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Progressive Collapse of WTC 7 – 2008 NIST Recommendations – Part 2 of 2

CJ Walsh — Sun, 22 Jan 2012 18:20:54 +0000

1st Series of Posts on the 2005 NIST WTC 1 & 2 Collapse Recommendations … which began towards the end of 2011 …

2011-10-25: NIST’s Recommendations on the 9-11 WTC Building Collapses … GROUP 1. Increased Structural Integrity – Recommendations 1, 2 & 3 (out of 30)

Previous Post in this New Series …

2012-01-18: Progressive Collapse of WTC 7 – 2008 NIST Recommendations - Part 1 of 2 … GROUP 1. Increased Structural Integrity – Recommendation A … and GROUP 2. Enhanced Fire Endurance of Structures – Recommendations B, C, D & E (out of 13)

2012-01-22: SOME PRELIMINARY COMMENTS …

1. Keeping my ear closely to the ground … I hear you wondering: ”So … how did the fires actually start in World Trade Center Building 7 ?”

Extracts from the Executive Summary (pages xxxi – xxxv) – 2008 NIST NCSTAR 1A …

[ Refer back to the WTC 1 & 2 Collapse Damage Plan in the previous post.]

The fires in WTC Building 7 were ignited as a result of the impact of debris from the collapse of WTC Tower 1, which was approximately 110 metres to the south. The debris also caused some structural damage to the south-west perimeter of WTC 7. The fires were ignited on at least 10 floors; however, only the fires on Floors 7 to 9 and 11 to 13 grew and lasted until the time of building collapse. These uncontrolled fires had characteristics similar to those that have occurred previously in tall buildings. Their growth and spread were consistent with ordinary building content fires. Had a water supply for the automatic sprinkler system been available and had the sprinkler system operated as designed, it is likely that the fires in WTC 7 would have been controlled, and the collapse prevented. However, the collapse of WTC 7 highlights the importance of designing fire resisting structures for situations where sprinklers are not present, do not function (e.g. due to disconnected or impaired water supply), or are overwhelmed.

and …

There were no serious injuries or fatalities, because the estimated 4,000 occupants of WTC 7 reacted to the airplane impacts on the two WTC Towers and began evacuating before there was significant damage to WTC 7. The occupants were able to use both the elevators and the stairs, which were as yet not damaged, obstructed, or smoke-filled. Evacuation of the building took just over an hour. The potential for injuries to people leaving the building was mitigated by building management personnel holding the occupants in the lobby until they identified an exit path that was safe from the debris falling from WTC Tower 1. The decisions not to continue evaluating the building and not to fight the fires were made hours before the building collapsed, so no emergency responders were in or near the building when the collapse occurred.

and …

The design of WTC 7 was generally consistent with the New York City Building Code of 1968 (NYCBC), with which, by policy, it was to comply. The installed thickness of the thermal insulation on the floor beams was below that required for unsprinklered or sprinklered buildings, but it is unlikely that the collapse of WTC 7 could have been prevented even if the thickness had been consistent with building code requirements. The stairwells were narrower than those required by the NYCBC, but, combined with the elevators, were adequate for a timely evacuation on 11 September 2001, since the number of building occupants was only about half that expected during normal business hours.

The collapse of WTC 7 could not have been prevented without controlling the fires before most of the combustible building contents were consumed. There were two sources of water (gravity-fed overhead tanks and the city water main) for the standpipe and automatic sprinkler systems serving Floor 21 and above, and some of the early fires on those upper floors might have actually been controlled in this manner. However, consistent with the NYCBC, both the primary and back-up source of water for the sprinkler system in the lower 20 floors of WTC 7 was the city water main. Since the collapses of the WTC Towers had damaged the water main, there was no water available (such as the gravity-fed overhead tanks that supplied water to Floor 21 and above) to control those fires that eventually led to the building collapse.

Link to read and/or download a copy of the 2008 NIST NCSTAR 1A Report … www.fireox-international.eu/fire/structdesfire.htm

2. On a separate subject and quite by chance … a few days ago, I was invited to review a technical paper for a reputable international fire engineering journal (which shall remain nameless). The paper was discussing a certain aspect of steel column critical temperatures. After three days, I replied to the journal’s editor as follows …

2012-01-18.

Most regrettably, I must decline your invitation to review Paper XYZ.

The ‘critical temperature’ approach to the fire engineering design of steel-framed structures is deeply flawed … and obsolete.

C. J. Walsh, FireOx International – Ireland, Italy & Turkey.

The ‘critical temperature’ approach is antiquated … and this nonsense has got to stop ! NOW … would be the best time !!

3. In the last post, I wrote …

Structural Fire Engineering is concerned with those aspects of fire engineering which relate to structural design for fire, and the complex architectural interaction between a building’s structure and fabric, i.e. non-structure, under conditions of fire and its immediate aftermath.

Indeed ! But, more needs to be added …

I hope it is becoming clearer now that Structural Fire Engineering is not just ambient structural engineering with a few extra ‘bells and whistles’ grafted on … in token consideration of what could happen in fire conditions, i.e. at high temperatures.

[ If, in some jurisdictions, there are no legal requirements to add even those 'bells and whistles' ... then, typically, even they will be omitted ! ]

This brings me right back to the typical education of Civil/Structural Engineers; because: (i) they exit the educational system with little understanding of anything beyond ‘structure’ … in other words, a ‘real’ building, which also comprises ‘fabric’, i.e. non-structure, is a mystery to them; and (ii) they have difficulty reading architectural drawings … which is why a walk-through inspection of a building, as it is nearing completion, is much preferred over a detailed discussion about drawings at the most appropriate stage, which is well before construction commences … when faults can be readily identified and easily rectified !

In ambient conditions … the architectural interaction between a building’s structure and fabric is difficult, not being entirely static. Before the surface finishes have been applied, it is immediately obvious when this interaction has been properly ‘designed’, and looks neat and tidy … or, on the vast majority of construction sites, when this interaction is a ‘traffic accident’, and the results are desperately ugly … and you know that they can’t apply the surface finishes quickly enough in order to hide everything from view !

In fire conditions … this architectural interaction between building fabric and structure is complex, certainly very dynamic … and fluid !

It would be more appropriate to think of Structural Fire Engineering as ‘Design in the Hot Form’ … which is a completely different mindset.

It is essential, therefore, that Fire Engineers understand ‘real’ buildings … most importantly, the ‘design’ of real buildings … and, that they know which end is ‘up’ on a real construction site !! See NIST WTC 7 Recommendation L below.

4. Since the collapse of WTC Building 7 on 11 September 2001, it has been generally assumed that Fire-Induced Progressive Collapse is a large-scale, macro-phenomenon only. But, believe it or not, this phenomenon has also been observed at micro-level in small building types.

In fact … Progressive Collapse was already receiving sporadic attention, in Ireland, as far back as the 1980′s …

As organizer of the 1987 Dublin International Fire Conference: ‘Fire, Access & Safety in Residential Buildings’, I requested that the following Paper be presented … ‘Design against Progressive Collapse in Fire’ … by Dr. Willie Crowe, who was Head of Construction Technology, in the old Institute for Industrial Research & Standards (IIRS) in Ireland. He later became Manager of the Irish Agrément Board (IAB). Those were the days … and Willie really knew his stuff !

Mr. Noel C. Manning, of FireBar in Ireland (www.firebar.ie), and I both contributed to the development of his Paper.

And now is as good a time as any to give full credit to Noel Manning for his innovative approach to Structural Fire Engineering back in the early 1980′s. He’s a ‘hard man’ … a term that we use for some special people in Ireland !

Link to the Dublin International Fire Conferences, and a copy of this Paper … www.fireox-international.eu/fire/dublinfire.htm

For approximately 12 years from the mid-1980′s, I was a Member of the National Masonry Panel – the National Standards Authority of Ireland (NSAI) Masonry Standards Advisory Committee. A small, but substantial, text on Fire-Induced Progressive Collapse in Buildings was included, by me, in the following standard … Irish Standard 325: Code of Practice for Use in Masonry – Part 2: Masonry Construction (1995). Appendix A – Determination of Movement in Masonry. A.3 – Thermal Movement. Once again … those were the days … when I was the only architect in a sea of engineers !! Not a pretty experience.

5. What next ? A final draft of the International CIB W14 Research WG IV Reflection Document on Fire-Induced Progressive Collapse will be completed in time for circulation to all CIB W14 members before the end of March 2012 … well in time for the next CIB W14 Meetings in Greece, near the end of April 2012.

2008 NIST WTC 7 RECOMMENDATIONS (Final Report NCSTAR 1A)

5.1.3 GROUP 3. New Methods for Fire Resisting Design of Structures

The procedures and practices used in the fire resisting design of structures should be enhanced by requiring an objective that uncontrolled fires result in burnout without partial or global (total) collapse. Performance-based methods are an alternative to prescriptive design methods. This effort should include the development and evaluation of new fire resisting coating materials and technologies, and evaluation of the fire performance of conventional and high-performance structural materials.

NIST WTC 7 Recommendation F (NCSTAR 1 Recommendation 8).

NIST recommends that the fire resistance of structures be enhanced by requiring a performance objective that uncontrolled building fires result in burnout without partial or global (total) collapse. Such a provision should recognize that sprinklers could be compromised, non-operational, or non-existent. Current methods for determining the fire resistance of structural assemblies do not explicitly specify a performance objective. The rating resulting from current test methods indicates that the assembly (component or sub-system) continued to support its superimposed load (simulating a maximum load condition) during the test exposure without collapse. Model Building Codes: This Recommendation should be included in the national model building codes as an objective, and adopted as an integral pert of the fire resistance design for structures. The issue of non-operational sprinklers could be addressed using the existing concept of Design Scenario 8 of NFPA 5000, where such compromise is assumed and the result is required to be acceptable to the Authority Having Jurisdiction (AHJ). Affected Standards: ASCE-7, AISC Specifications, ACI 318, and ASCE/SFPE 29.

Relevance to WTC 7: Large, uncontrolled fires led to failure of a critical column and consequently the complete collapse of WTC 7. In the region of the collapse initiation (i.e. on the east side of Floor 13), the fire had consumed virtually all of the combustible building contents, yet collapse was not prevented.

NIST WTC 7 Recommendation G (NCSTAR 1 Recommendation 9).

NIST recommends the development of: (1) performance-based standards and code provisions, as an alternative to current prescriptive design methods, to enable the design and retrofit of structures to resist real building fire conditions, including their ability to achieve the performance objective of burnout without structural or local fire collapse; and (2) the tools, guidelines, and test methods necessary to evaluate the fire performance of the structure as a whole system. Standards development organizations, including the American Institute of Steel Construction, have already begun developing performance-based provisions to consider the effects of fire in structural design.

a. Standard methodology, supported by performance criteria, analytical design tools, and practical design guidance; related building standards and codes for fire resistance design and retrofit of structures, working through the consensus process for nationwide adoption; comprehensive design rules and guidelines; methodology for evaluating thermo-structural performance of structures; and computational models and analysis procedures for use in routine design practice.

b. Standard methodology for specifying multi-compartment, multi-floor fire scenarios for use in the design and analysis of structures to resist fires, accounting for building-specific conditions such as geometry, compartmentation, fuel load (e.g. building contents and any flammable fuels such as oil and gas), fire spread, and ventilation; and methodology for rating the fire resistance of structural systems and barriers under realistic design-basis fire scenarios.

c. Publicly available computational software to predict the effects of fires in buildings – developed, validated, and maintained through a national effort – for use in the design of fire protection systems and the analysis of building response to fires. Improvements should include the fire behaviour and contribution of real combustibles; the performance of openings, including door openings and window breakage, that controls the amount of oxygen available to support the growth and spread of fires and whether the fire is fuel-controlled or ventilation-controlled; the floor-to-floor flame spread; the temperature rise in both insulated and un-insulated structural members and fire barriers; and the structural response of components, sub-systems, and the total building system due to the fire.

d. Temperature-dependent thermal and mechanical property data for conventional and innovative construction materials.

e. New test methods, together with associated conformance assessment criteria, to support the performance-based methods for fire resistance design and retrofit of structures. The performance objective of burnout without collapse will require the development of standard fire exposures that differ from those currently used.

There is a critical gap in knowledge about how structures perform in real fires, particularly concerning: the effects of fire on the entire structural system (including thermal expansion effects at lower temperatures); interaction between the sub-systems, elements, and connections; and scaling of fire test results to full-scale structures (especially for structures with long-span floor systems).

Relevance to WTC 7: A performance-based assessment of the effects of fire on WTC 7, had it considered all of the relevant thermal effects (e.g. thermal expansion effects that occur at lower temperatures), would have identified the vulnerability of the building to fire-induced progressive collapse and allowed alternative designs for the structural system.

5.1.4 GROUP 4. Improved Active Fire Protection

Active fire protection systems (i.e. sprinklers, standpipes/hoses, fire alarms, and smoke management systems) should be enhanced through improvements to the design, performance, reliability, and redundancy of such systems.

NIST WTC 7 Recommendation H (NCSTAR 1 Recommendation 12).

NIST recommends that the performance, and possibly the redundancy and reliability of active fire protection systems (sprinklers, standpipes/hoses, fire alarms, and smoke management systems), in buildings be enhanced to accommodate the greater risks associated with increasing building height and population, increased use of open spaces, high-risk building activities, fire department response limits, transient fuel loads, and higher threat profile.

Reliability is affected by (a) redundancy, such that when one water supply is out of service (usually for maintenance), the other interconnected water supply can continue to protect the building and its occupants; (b) automatic operation of water supply systems (not only for starting fire pumps but also for testing and tank replenishment, with appropriate remote alarms to the fire department and local alarms for notifying emergency personnel); and (c) the use of suitable equipment and techniques to regulate unusual pressure considerations.

Relevance to WTC 7: No water was available for the automatic suppression systems on the lower 20 storeys of WTC 7, once water from street-level mains was disrupted. This lack of reliability in the source of the primary and secondary water supplies allowed the growth and spread of fires that ultimately resulted in collapse of the building.

5.1.5 GROUP 6. Improved Emergency Response

Technologies and procedures for emergency response should be improved to enable better access to buildings, response operations, emergency communications, and command and control in large-scale emergencies.

NIST WTC 7 Recommendation I (NCSTAR 1 Recommendation 24).

NIST recommends the establishment and implementation of codes and protocols for ensuring effective and uninterrupted operation of the command and control system for large-scale building emergencies.

a. State, local, and federal jurisdictions should implement the National Incident Management System (NIMS). The jurisdictions should work with the Department of Homeland Security to review, test, evaluate, and implement an effective unified command and control system. NIMS addresses interagency co-ordination and establishes a response matrix – assigning lead agency responsibilities for different types of emergencies, and functions. At a minimum, each supporting agency should assign an individual to provide co-ordination with the lead agency at each incident command post.

b. State, local, and federal emergency operations centres (EOC’s) should be located, designed, built, and operated with security and operational integrity as a key consideration.

c. Command posts should be established outside the potential collapse footprint of any building which shows evidence of large multi-floor fires or has serious structural damage. A continuous assessment of building stability and safety should be made in such emergencies to guide ongoing operations and enhance emergency responder safety. The information necessary to make these assessments should be made available to those assigned responsibility (see related Recommendations 15 and 23 in NIST NCSTAR 1).

d. An effective command system should be established and operating before a large number of emergency responders and apparatus are dispatched and deployed. Through training and drills, emergency responders and ambulances should be required to await dispatch requests from the incident command system and not to self-dispatch in large-scale emergencies.

e. Actions should be taken via training and drills to ensure a co-ordinated and effective emergency response at all levels of the incident command chain by requiring all emergency responders that are given an assignment to immediately adopt and execute the assignment objectives.

f. Command post information and incident operations data should be managed and broadcast to command and control centres at remote locations so that information is secure and accessible by all personnel needing the information. Methods should be developed and implemented so that any information that is available at an interior information centre is transmitted to an emergency responder vehicle or command post outside the building.

Relevance to WTC 7: (1) The New York City Office of Emergency Management (OEM) was located in WTC 7 and was evacuated before key fire ground decisions had to be made. The location of OEM in WTC 7, which collapsed due to ordinary building fires, contributed to the loss of robust interagency command and control on 11 September 2001. (2) Due to the collapse of the WTC Towers and the loss of responders and fire control resources, there was an evolving site leadership during the morning and afternoon. Key decisions (e.g. not to fight the fires in WTC 7 and to turn off power to the Con Edison substation) were reasonable and would not have changed the outcome on 11 September 2001, but were not made promptly. Under different circumstances (e.g. if WTC 7 had collapsed sooner and firefighters were still evaluating the building condition), the outcome could have been very different.

5.1.6 GROUP 7. Improved Procedures and Practices

The procedures and practices used in the design, construction, maintenance, and operation of buildings should be improved to include encouraging code compliance by non-governmental and quasi-governmental entities, adoption and application of evacuation and sprinkler requirements in codes for existing buildings, and retention and availability of building documents over the life of a building.

NIST WTC 7 Recommendation J (NCSTAR 1 Recommendation 27).

NIST recommends that building codes incorporate a provision that requires building owners to retain documents, including supporting calculations and test data, related to building design, construction, maintenance, and modifications over the entire life of the building.* Means should be developed for off-site storage and maintenance of the documents. In addition, NIST recommends that relevant information be made available in suitably designed hard copy or electronic formats for use by emergency responders. Such information should be easily accessible by responders during emergencies.

[ * F-12 The availability of inexpensive electronic storage media and tools for creating large searchable databases makes this feasible.]

Relevance to WTC 7: The efforts required in locating and acquiring drawings, specifications, tenant layouts, and material certifications, and especially shop fabrication drawings, significantly lengthened the investigation into the collapse of WTC 7.

NIST WTC 7 Recommendation K (NCSTAR 1 Recommendation 28).

[ * F-13 In projects involving a design team, the 'Design Professional in Responsible Charge' - usually the lead architect - ensures that the team members use consistent design data and assumptions, co-ordinates overlapping specifications, and serves as the liaison between the enforcement and reviewing officials and the owner. This term is defined in the International Building Code (IBC) and in the International Code Council's Performance Code for Buildings and Facilities (where it is the Principal Design Professional).]

Relevance to WTC 7: Following typical practice, none of the design professionals in charge of the WTC 7 Project (i.e. architect - structural engineer - fire protection engineer) was assigned the responsibility to explicitly evaluate the fire performance of the structural system. Holistic consideration of thermal and structural factors during the design or review stage could have identified the potential for the failure and might have prevented the collapse of the building.

5.1.7 GROUP 8. Education and Training

The professional skills of building and fire safety professionals should be upgraded through a national education and training effort for fire protection engineers, structural engineers, and architects. The skills of building regulatory and fire service personnel should also be upgraded to provide sufficient understanding and the necessary skills to conduct the review, inspection, and approval tasks for which they are responsible.

NIST WTC 7 Recommendation L (NCSTAR 1 Recommendation 29).

NIST recommends that continuing education curricula be developed, and programmes be implemented for: (1) training fire protection engineers and architects in structural engineering principles and design; and (2) training structural engineers, architects, fire protection engineers, and code enforcement officials in modern fire protection principles and technologies, including the fire resisting design of structures; and (3) training building regulatory and fire service personnel to upgrade their understanding and skills to conduct the review, inspection, and approval tasks for which they are responsible. The outcome would further the integration of the disciplines in effective fire-safe design of buildings.

Relevance to WTC 7: Discerning the fire-structure interactions that led to the collapse of WTC 7 required research professionals with expertise in both disciplines. Assuring the safety of future buildings will require that participants in the design and review processes possess a combined knowledge of fire science, materials science, heat transfer, and structural engineering, and design.

NIST WTC 7 Recommendation M (NCSTAR 1 Recommendation 30).

NIST recommends that academic, professional short-course, and web-based training materials in the use of computational fire dynamics and thermo-structural analysis tools be developed and delivered to strengthen the base of available technical capabilities and human resources.

Relevance to WTC 7: NIST stretched the state-of-the-art in the computational tools needed to reconstruct a fire-induced progressive collapse. This enabled identification of the critical processes that led to that collapse. Making these expanded tools and derivative, validated, and simplified modelling approaches usable by practitioners could prevent future disasters.

END

Progressive Collapse of WTC 7 – 2008 NIST Recommendations – Part 1 of 2

CJ Walsh — Wed, 18 Jan 2012 17:29:05 +0000

See the 1st Series of Posts on the 2005 NIST WTC 1 & 2 Collapse Recommendations … which began, here, towards the end of 2011 …

2011-10-25: NIST’s Recommendations on the 9-11 WTC Building Collapses … GROUP 1. Increased Structural Integrity – Recommendations 1, 2 & 3 (out of 30)

Colour plan showing the World Trade Center Complex in New York City, and its surrounding neighbourhood in Manhattan. By means of yellow shading and annotation in red text, the extent of direct damage caused by the collapse of the 2 WTC Towers on 11 September 2001 is shown. Not shown is the much greater extent of indirect damage caused, e.g. dust and debris from the collapses clogged up and destroyed air conditioning systems and ductwork in buildings. Everywhere south of Canal Street was a disaster zone. Also not shown is the damage caused by WTC 7, at the north-eastern tip of the Complex, which collapsed late on the afternoon of 9-11. Click to enlarge.

2012-01-18: SOME PRELIMINARY COMMENTS …

1. World Trade Center Building 7 was a 47 Storey Office Building located at the north -eastern tip of the WTC Complex in Lower Manhattan, New York City. It had been built on top of an existing Consolidated Edison of New York electric power substation, on land owned by the Port Authority of New York and New Jersey.

On Tuesday, 11 September 2001 … WTC Building 7 was on fire for almost seven hours … from the time of the collapse of WTC Tower 1 – North Tower, just before 10.30 hrs (local time), until 17.21 hrs … when WTC 7 failed completely, collapsing progressively as a result of ‘real’ fires – as distinct from ‘standard test’ fires – on many floors.

There were only two certainties on that fateful day (9-11) … the Fire-Induced Progressive Collapse of WTC Building 7 could no longer be ignored by the International Fire Science and Engineering Community … and the ‘reality’, which Modern Fire Engineering must now confront, was significantly altered. Secondly, it is NEVER acceptable to a general population for buildings to collapse !

Later in 2008, the Mumbai ‘Hive’ Attacks would add a sinister new ingredient to the standard threat profile for buildings, their occupants, and emergency services.

However, long before 9-11 and Mumbai, the growing complexity of modern communities and their rapidly evolving architectural forms had left the Fire Engineer far behind, unable to respond to the new fire safety challenges posed.

2. The second of the NIST Publications being referenced in this New Series of Posts is as follows …

NIST (National Institute of Standards and Technology). August 2008. Federal Building and Fire Safety Investigation of the World Trade Center Disaster: Final Report on the Collapse of World Trade Center Building 7. NIST NCSTAR 1A. Gaithersburg, MD, USA.

This 2008 NIST Report contains, in Chapter 5, a list of 13 Recommendations for Action (A-M), grouped together under the same 8 Subject Headings used in the 2005 NIST Report (NCSTAR 1) …

i) Increased structural integrity … Recommendation A ;

ii) Enhanced fire endurance of structures … Recommendations B, C, D & E ;

iii) New methods for fire resisting design of structures … Recommendations F & G ;

iv) Improved active fire protection … Recommendation H ;

v) Improved building evacuation … Long before its collapse, all occupants/users had evacuated WTC 7 … No Recommendation ;

vi) Improved emergency response … Recommendation I ;

vii) Improved procedures and practices … Recommendations J & K ; and

viii) Education and training … Recommendations L & M.

NIST has clearly stated that “the urgency of these Recommendations is substantially reinforced by their pertinence to the collapse of a tall building that was based on a structural system design that is in widespread use”.

3. The Colour Coding of Texts which I am using in this new series of posts … where NIST has presented new texts relating to WTC Building 7, these are shown in blue … where NIST has chosen to reinforce earlier texts from the 2005 Report on the WTC Towers 1 & 2 Collapses, these are shown in black. The important new paragraphs describing the critical relevance of WTC Building 7 are shown in red.

Please pay particular attention to these Red Paragraphs. Having carefully digested their contents … then if, by any chance, you happen to encounter somebody who still insists that the NIST 9-11 WTC Recommendations have no relevance to the design, construction, management and operation of ALL Buildings … that person is either living in Alice’s Wonderland … or he/she has never bothered to read the NIST Recommendations in the first place !!

4. While it is still essential to distinguish clearly between the two closely related structural concepts below … I would like to take this opportunity to bring to your attention a necessary and important modification … more, a refinement … to the definition of Fire-Induced Progressive Collapse …

Disproportionate Damage

The failure of a building’s structural system (i) remote from the scene of an isolated overloading action; and (ii) to an extent which is not in reasonable proportion to that action.

Fire-Induced Progressive Collapse

The sequential growth and intensification of structural distortion and displacement, beyond fire engineering design parameters, and the eventual failure of elements of construction in a building – during a fire and the ‘cooling phase’ afterwards – which, if unchecked, will result in disproportionate damage, and may lead to total building collapse.

This modification/refinement recognizes the following … that Fire-Induced Progressive Collapse may commence long before any breach occurs in a Fire Compartment Boundary … that, as a result of rampant commercial pressures in our societies, the tendency is for Compartment Volumes to become far too large to be any longer effective … and in the case of a Sustainable Building, for example, where natural patterns of air movement in buildings are used for either heating or cooling purposes, there may be no Compartments at all !

Restricting the application of one or both of these structural concepts, in law, to Multi-Storey Buildings, i.e. in many jurisdictions, those buildings having 5 or more storeys … is a purely arbitrary cut-off point.

CIB W14′s Research Working Group IV: ‘Structural Reliability & Fire-Induced Progressive Collapse’ would argue, rationally, that both of these concepts are fundamental to all structural fire engineering design.

5. Structural Fire Engineering is concerned with those aspects of fire engineering which relate to structural design for fire, and the complex architectural interaction between a building’s structure and fabric, i.e. non-structure, under conditions of fire and its immediate aftermath.

As Chair of CIB W14′s Research Working Group IV … I will shortly be making a Workshop Presentation in Europe, the aim of which will be to set the scene for the launch of an International CIB W14 Research WG IV Reflection Document; the specific objective of the Presentation, however, will be to accurately describe the phenomenon that is Fire-Induced Progressive Collapse … and to outline a necessary new design approach which will fulfil future requirements, legal and otherwise, concerning adequate resistance to this phenomenon.

It will be shown that the new design approach is fully compatible with the Recommendations contained in the 2005 and 2008 NIST Reports on the 9-11 World Trade Center Buildings 1, 2 & 7 Collapses – NCSTAR 1 & NCSTAR 1A.

2008 NIST WTC 7 RECOMMENDATIONS (Final Report NCSTAR 1A)

5.1 GENERAL

In its final report on the collapse of the World Trade Center Towers (NIST NCSTAR 1), NIST made 30 Recommendations for improving the safety of buildings, occupants, and emergency responders. These encompass increased structural integrity, enhanced fire endurance of structures, new methods for fire resisting design of structures, improved active fire protection, improved building evacuation, improved emergency response, improved procedures and practices, and education and training.

WTC 7 was unlike the WTC Towers in many respects. It was a more typical tall building in the design of its structural system. It was not struck by an airplane. The fires in WTC 7 were quite different from those in the Towers. Since WTC 7 was not doused with thousands of litres of jet fuel, large areas of any floor were not ignited simultaneously. Instead, the fires in WTC 7 were similar to those that have occurred previously in several tall buildings where the sprinklers did not function or were not present. These other buildings did not succumb to their fires and collapse, because they were of structural designs that differed from that of WTC 7.

The Investigation Team has compiled a list of key factors that enabled ordinary fires to result in an extraordinary outcome. In so doing, the Team recognized that there were additional aspects to be included in the content of some of the earlier 30 Recommendations.

Based on the findings of this Investigation, NIST has identified 1 New Recommendation and has reiterated 12 Recommendations from the Investigation of the WTC Towers.

The urgency of the Prior Recommendations is substantially reinforced by their pertinence to the collapse of a tall building that is based on a structural system design that is in widespread use. A few of the Prior Recommendations have been modified to reflect the findings of this Investigation.

The partial or total collapse of a building due to fires is an infrequent event. This is particularly true for buildings with a reliably operating active fire protection system, such as an automatic fire sprinkler system. A properly designed and operating automatic sprinkler system will contain fires while they are small and, in most instances, prevent them from growing and spreading to threaten structural integrity.

The intent of current practice, based on prescriptive standards and codes, is to achieve life safety, not collapse prevention. However, the key premise of NIST’s Recommendations is that buildings should not collapse in infrequent (worst-case) fires that may occur when active fire protection systems are rendered ineffective, e.g. when sprinklers do not exist, are not functional, or are overwhelmed by the fire.

Fire scenarios for structural design based on single compartment or single floor fires are not appropriate representations of infrequent fire events. Such events have occurred in several tall buildings resulting in unexpected substantial losses. Instead, historical data suggests that infrequent fires which should be considered in structural design have characteristics that include: ordinary combustibles and combustible load levels, local fire origin on any given floor, no widespread use of accelerants, consecutive fire spread from combustible to combustible, fire-induced window breakage providing ventilation for continued fire spread and accelerated fire growth, concurrent fires on multiple floors, and active fire protection systems rendered ineffective. The fires in WTC 7 had all of these characteristics.

NIST believes the Recommendations are realistic, appropriate, and achievable within a reasonable period of time. NIST strongly urges that immediate and serious consideration be given to these Recommendations by the building and fire safety communities in order to achieve appropriate improvements in the way buildings are designed, constructed, maintained, and used – with the goal of making buildings safer in future emergencies.

A complete listing of all 13 Recommendations (Recommendations A through L) based on this Investigation follows. Under a few of the Recommendations, the pertinent lesson from the reconstruction of the WTC 7 Collapse is reflected in the form of a modification. For the 12 Reiterated Recommendations, the pertinent codes, standards, and organizations were listed in Table 9-1, and Tables 9-2a through 9-2c of NIST NCSTAR 1 and are not repeated here. For the 1 New Recommendation, B, this information is provided in the text.

5.1.1 GROUP 1. Increased Structural Integrity

The standards for estimating the load effects of potential hazards (e.g. progressive collapse, wind) and the design of structural systems to mitigate the effects of those hazards should be improved to enhance structural integrity.

NIST WTC 7 Recommendation A (NCSTAR 1 Recommendation 1).

NIST recommends that: (1) progressive collapse be prevented in buildings through the development and nationwide adoption of consensus standards and code provisions, along with the tools and guidelines needed for their use in practice; and (2) a standard methodology be developed – supported by analytical design tools and practical design guidance – to reliably predict the potential for complex failures in structural systems subjected to multiple hazards.

Relevance to WTC 7: Had WTC 7 been expressly designed for prevention of fire-induced progressive collapse, it would have been sufficiently robust to withstand local failure due to the fires without suffering total collapse.

5.1.2 GROUP 2. Enhanced Fire Endurance of Structures

The procedures and practices used to ensure the fire endurance of structures should be enhanced by improving the technical basis for construction classifications and fire resistance ratings, improving the technical basis for standard fire resistance testing methods, use of the ‘structural frame’ approach to fire resistance ratings, and developing in-service performance requirements and conformance criteria for sprayed fire resisting materials.

NIST WTC 7 Recommendation B (New)

NIST recommends that buildings be explicitly evaluated to ensure the adequate performance of the structural system under worst-case design fires with any active fire protection system rendered ineffective. Of particular concern are the effects of thermal expansion in buildings with one or more of the following features: (1) long-span floor systems* which experience significant thermal expansion and sagging effects; (2) connection designs (especially shear connections) that cannot accommodate thermal effects; (3) floor framing that induces asymmetric thermally-induced (i.e. net lateral) forces on girders; (4) shear studs that could fail due to differential thermal expansion in composite floor systems; and (5) lack of shear studs on girders. Careful consideration should also be given to the possibility of other design features that may adversely affect the performance of the structural system under fire conditions.

[ * F-6 Typical floor span lengths in tall office buildings are in the range of 12-15 metres; this range is considered to represent long-span systems. Thermal effects (e.g. thermal expansion) that may be significant in long-span buildings may also be present in buildings with shorter span lengths, depending on the design of the structural system.]

Building owners, operators, and designers are strongly urged to act upon this Recommendation. Engineers should be able to design cost-effective fixes to address any areas of concern that are identified by these evaluations. Several existing, emerging, or even anticipated capabilities could have helped prevent the collapse of WTC 7. The degree to which these capabilities improve performance remains to be evaluated. Possible options for developing cost-effective fixes include:

More robust connections and framing systems to better resist the effects of thermal expansion on the structural system ;
Structural systems expressly designed to prevent progressive collapse. The current model building codes do not require that buildings be designed to resist progressive collapse ;
Better thermal insulation (i.e. reduced conductivity and/or increased thickness) to limit heating of structural steel and to minimize both thermal expansion and weakening effects. Currently, insulation is used to protect steel strength, but it could also be used to maintain a lower temperature in the steel framing to limit thermal expansion ;
Improved compartmentation in tenant areas to limit spread of fires ;
Thermally resisting window assemblies which limit breakage, reduce air supply, and retard fire growth.

Industry should partner with the research community to fill critical gaps in knowledge about how structures perform in real fires, particularly considering: the effects of fire on the entire structural system; the interactions between sub-systems, elements, and connections; and scaling of fire test results to full-scale structures, especially for structures with long-span floor systems.

Affected Standards: ASCE 7, ASCE/SFPE 29, AISC Specifications, and ACI 318. Development of performance objectives, design criteria, evaluation methods, design guidance, and computational tools should begin promptly, leading to new standards.

Model Building Codes: The new standard should be adopted in model building codes (IBC, NFPA 5000) by mandatory reference to, or incorporation of, the latest edition of the standard.

Relevance to WTC 7: The effects of restraint of free thermal expansion on the steel framing systems, especially for the long spans on the east side of WTC 7, were not considered in the structural design and led to the initiation of the building collapse.

NIST WTC 7 Recommendation C (NCSTAR 1 Recommendation 4).

NIST recommends evaluating, and where needed improving, the technical basis for determining appropriate construction classifications and fire rating requirements (especially for tall buildings) – and making related code changes now, as much as possible – by explicitly considering factors including:*

[ * F-7 The construction classification and fire rating requirements should be risk-consistent with respect to the design-basis hazards and the consequences of those hazards. The fire rating requirements, which were originally developed based on experience with buildings less than 20 storeys in height, have generally decreased over the past 80 years since historical fire data for buildings suggest considerable conservatism in those requirements. For tall buildings, the likely consequences of a given threat to an occupant on the upper floors are more severe than the consequences to an occupant on the first floor or the lower floors. For example, with non-functioning elevators, both of the time requirements are much greater for full building evacuation from upper floors and emergency responder access to those floors. The current height and areas tables in building codes do not provide the technical basis for the progressively increasing risk to an occupant on the upper floors of tall buildings that are much greater than 20 storeys in height.]

timely access by emergency responders and full evacuation of occupants, or the time required for burnout without partial collapse ;
the extent to which redundancy in active fire protection systems (sprinklers and standpipe, fire alarm, and smoke management) should be credited for occupant life safety ;*

[ * F-8 Occupant life safety, prevention of fire spread, and structural integrity are considered separate safety objectives.]

the need for redundancy in fire protection systems that are critical to structural integrity ;*

[ * F-9 The passive fire protection system (including the application of fire protection insulation, compartmentation, and fire stopping) and the active sprinkler system each provide redundancy for maintaining structural integrity in a building fire, should one of the systems fail to perform its intended function.]

the ability of the structure and local floor systems to withstand a maximum credible fire scenario* without collapse, recognizing that sprinklers could be compromised, not operational, or non-existent ;

[ * F-10 A maximum credible fire scenario includes conditions that are severe, but reasonable to anticipate, conditions related to building construction, occupancy, fire loads, ignition sources, compartment geometry, fire control methods, etc., as well as adverse, but reasonable to anticipate operating conditions.]

compartmentation requirements (e.g. 1,200 sq.m*) to protect the structure, including fire rated doorsets and automatic enclosures, and limiting air supply (e.g. thermally resisting window assemblies) to retard fire spread in buildings with large, open floor plans ;

[ * F-11 Or a more appropriate limit, which represents a reasonable area for active fire fighting operations.]

the effect of spaces containing unusually large fuel concentrations for the expected occupancy of the building ; and
the extent to which fire control systems, including suppression by automatic or manual means, should be credited as part of the prevention of fire spread.

Relevance to WTC 7: The floor systems in WTC 7 failed at lower temperatures because thermal effects within the structural system, especially thermal expansion, were not considered in setting the fire rating requirements in the construction classification, which are determined using the ASTM E 119 or equivalent testing standard.

NIST WTC 7 Recommendation D (NCSTAR 1 Recommendation 5).

NIST recommends that the technical basis for the century-old standard for fire resistance testing of components, assemblies and systems be improved through a national effort. Necessary guidance also should be developed for extrapolating the results of tested assemblies to prototypical building systems. A key step in fulfilling this Recommendation is to establish a capability for studying and testing components, assemblies, and systems under realistic fire and load conditions.

Of particular concern is that the Standard Fire Resistance Test does not adequately capture important thermally-induced interactions between structural sub-systems, elements, and connections that are critical to structural integrity. System-level interactions, especially due to thermal expansion, are not considered in the standard test method since columns, girders, and floor sub-assemblies are tested separately. Also, the performance of connections under both gravity and thermal effects is not considered. The United States currently does not have the capability for studying and testing these important fire-induced phenomena critical to structural safety.

Relevance to WTC 7: The floor systems failed in WTC 7 at shorter fire exposure times than the specified fire rating (two hours) and at lower temperatures because thermal effects within the structural system, especially thermal expansion, were not considered in setting the endpoint criteria when using the ASTM E 110 or equivalent testing standard. The structural breakdowns that led to the initiating event, and the eventual collapse of WTC 7, occurred at temperatures that were hundreds of degrees below the criteria that determine structural fire resistance ratings.

NIST WTC 7 Recommendation E (NCSTAR 1 Recommendation 7).

NIST recommends the adoption and use of the ‘structural frame’ approach to fire resistance ratings. This approach requires all members that comprise the primary structural frame (such as columns, girders, beams, trusses, and spandrels) be fire protected to the higher fire resistance rating required for the columns. The definition of the primary structural frame should be expanded to include bracing members that are essential to the vertical stability of the primary structural frame under gravity loading (e.g. girders, diagonal bracing, composite floor systems that provide lateral bracing to the girders) whether or not the bracing members carry gravity loads. Some of these bracing members may not have direct connections to the columns, but provide stability to those members directly connected to the columns. This Recommendation modifies the definition of the primary structural frame adopted in the 2007 supplement to the International Building Code (IBC). The IBC considers members of floor or roof construction that are not connected to the columns not to be part of the primary structural frame. This Recommendation ensures consistency in the fire protection provided to all of the structural elements that contribute to overall structural stability. State and local jurisdictions should adopt and enforce this requirement.

Relevance to WTC 7: Thermally-induced breakdown of the floor system in WTC 7 was a determining step in causing failure initiation and progressive collapse. Therefore, the floor system should be considered as an integral part of the primary structural frame.

END

Emergency Services in Europe – Occupational Health & Safety

CJ Walsh — Sat, 14 Jan 2012 15:12:39 +0000

2012-01-14: I do hope that everyone had a wonderful Christmas and New Year’s Eve ! I spent the time on an interesting project in Cuba … but more about that later.

Before launching into a new, much shorter series of posts on the 2008 NIST WTC Recommendations … I wanted to bring to your attention a related, and recently issued, EU-OSHA Publication: ‘Emergency Services: A Literature Review on Occupational Safety & Health Risks’. It can be downloaded at the end of this post.

I have touched upon this important issue before. AND … unfortunately, the lack of any proper consideration of this issue by Spatial Planners and Building Designers continues to receive insufficient attention at European and International Levels !

In its own explanatory blurb …

‘ The European Agency for Safety and Health at Work (EU-OSHA) contributes to making Europe a safer, healthier and more productive place to work. The Agency researches, develops, and distributes reliable, balanced, and impartial safety and health information and organizes pan-European awareness raising campaigns.

Set up by the European Union in 1996 and based in Bilbao, Spain, the Agency brings together representatives from the European Commission, Member State governments, employers’ and workers’ organizations, as well as leading experts in each of the EU-27 Member States and beyond.’

The EU-OSHA WebSite is located at … http://osha.europa.eu

EXECUTIVE SUMMARY – EU-OSHA ‘Emergency Services’ Publication (October 2011)

Emergency Workers comprise large professional groups ranging from career and volunteer firefighters, police officers, emergency medical staff (paramedics - emergency medical technicians - doctors - nurses) to psychologists. In major disasters, rescue workers, technicians from large relief organizations, additional medical staff, military personnel, anti-terrorist forces, body handlers, clean-up workers, construction workers, and numerous volunteers are involved. Depending on the emergency/disaster site, emergency workers need specialization, for instance in water rescue, mountain rescue or rescue from heights. Current environmental, economic, and political developments and trend data all suggest an increase in the severity and frequency of disasters in the future. Phenomena that support this assumption include increased energy use, progressive global warming, climate change and pollution, population growth, dispersal of industrialization around the globe, expansion of transportation facilities, and the growing spread of terrorism. The growing issue of better protection for emergency workers from Occupational Safety and Health (OSH) Risks has been emphasized as a priority by many experts. The demands made upon emergency workers, as well as the OSH Risks they are exposed to, will rise as they are confronted with events greater in both number and severity.

Although the exact number of emergency workers is difficult to estimate, the available figures and the large number of people affected by disasters and in need of immediate help are reliable indicators that emergency workers account for a significant proportion of the European Workforce. Exact numbers can be given for some groups, such as firefighters. According to the report by the International Labour Organization (ILO), in European countries there is on average one firefighter for every 1,000–1,200 inhabitants. There are also a considerable number of volunteer firefighters.

Emergency workers’ priorities are to protect human life, property and the environment, and their most common fields of action include:

everyday emergencies (road accidents, crime scenes, gas explosions, fires) ;
natural disasters (floods, storms, fires, earthquakes, volcanic eruptions) ;
industrial accidents (involving hazardous materials, such as in the nuclear and mining sectors) ;
transport accidents (major car crashes, plane crashes, rail accidents) ;
terrorist and criminal attacks (bomb attacks, gas attacks, shootings) ;
massive public events (negative events during concerts, sport events, demonstrations).

The absolute numbers of emergency workers involved in specific events are often not easy to obtain. Some figures can be found in media reports. Around 4,000 emergency workers were involved during mud spills in Hungary (2010); 5,500 police and emergency workers were mobilised to organize evacuation during crowd panic in Duisburg, Germany (2010); 240,000 emergency workers and 2,000 members of the armed forces dealt with forest fires in Russia (2010); more than 500 emergency workers were sent to a mine explosion in Russia (2010); 2,500 rescue workers, including 1,500 firefighters, were sent to the area affected by an earthquake in central Italy (2009); up to 70,000 emergency workers took part in the massive operation after the terrorist attack at the World Trade Center in New York, including policemen, firefighters, and construction workers (2001); 200,000 recovery workers were involved in clean-up activities in 1986–1987 after the nuclear disaster at Chernobyl (1986).

European emergency workers are often involved in dealing with major catastrophes that happen outside Europe. After the earthquake in Haiti (2010), a 64-member search and rescue team was sent from the UK; more than 500 personnel, particularly rescue workers, were sent by France; 450 troops, 50 doctors, technicians and specialists were sent from Spain; more than 20 emergency workers went from Portugal; a plane with a search and rescue team went from the Netherlands; and three medical teams were sent from Hungary.

All types of emergency workers can be involved in any kind of intervention, and the spectrum of possible demands and risks those workers may encounter is very wide. They may be especially high when the management and preparedness are poor, and there is lack of or insufficient co-ordination, information and communication, lack of training, and inappropriate or insufficient safety and personal protective equipment.

There are some General OSH Hazards and Risks likely to occur in any kind of emergency intervention:

Demanding work environment: working in remote, difficult to access areas; unstable and extremely difficult weather conditions; and unpredictable hazards at the disaster scene such as the danger of collapse of damaged structures. High risk of violence.
Emotional and psychological overstrain: dealing with many fatalities and injured people; high responsibility for people’s lives; time pressure; and long, unpredictable working hours.
Physical overstrain: physically demanding work; insufficient breaks; manual handling (wearing heavy protective equipment, transportation of patients, carrying dead bodies, removal of debris).

Additionally, particular types of emergency events are related to the greater possibility of other, more Specific OSH Hazards. Natural disasters may put emergency workers at risk of:

water-borne diseases where there is contact with contaminated water (diarrhoea, cholera, typhoid fever, hepatitis A, hepatitis E, parasitic diseases, rotavirus, and shigellosis) ;
infectious (tuberculosis) and blood-borne diseases (HIV, hepatitis B, and hepatitis C) as a consequence of contact with survivors and dead bodies, and the possibility of infection transmitted by needle-stick injuries ;
vector-borne diseases (malaria, dengue, St. Louis encephalitis, and West Nile fever) transmitted by mosquitoes ;
respiratory and asthmatic problems, including asphyxiation, heat stress, and the carcinogenic effects of volcanic eruptions, landslides and earthquakes, and fires leading to significant release of ash and gases, and dust ;
being trapped or seriously injured by debris, working in confined spaces, drowning, confrontation with wild, aggressive or infected, domestic animals.

Industrial Accidents may lead to:

fatalities, serious injuries, and short and long-term health problems stemming from accidents caused by explosions, followed by fires and the release of toxic substances; the health consequences may include headache, confusion, fainting, agitation, delirium or convulsions, respiratory complaints, cardiovascular complaints, renal failure, eye and skin problems and gastrointestinal problems ;
severe health consequences such as burns, skin diseases, and incurable diseases including different kinds of cancer, Acute Radiation Syndrome (ARS) and death as a result of nuclear radiation.

Transport Accidents may involve:

the risk of being struck by a passing vehicle ;
specific risks associated with accidents involving the transport of dangerous substances, hazardous materials, or stemming from burning fuel or chemicals used in vehicles which have ignited or exploded.

Terrorist and Criminal Attacks may involve:

unfamiliar, unpredictable, confused, and complex scenarios ;
the risk of death or serious injury, injury from weapons and the prospect of being taken as a hostage ;
the risk of being exposed to chemical and radiological hazards ;
a possibility of bio-terrorism using biological agents such as smallpox, anthrax, botulism, tularaemia, and viral haemorrhagic fevers which can be easily disseminated or transmitted from person to person and cause high mortality.

Negative Events during Massive Public Events may lead to:

specific risks, varying from scenario to scenario, including fire, collapsing buildings, violence, terrorist attacks ;
specific hazards stemming from violent behaviour and the unpredictable acts of a panicking crowd, such as people trying to escape from a confined space.

Emergency Workers are exposed to a combination of many different risks and there may be many possible consequences for their safety and health. Possible OSH outcomes have been explored by the analysis of relevant statistics and studies.

Although the risk of Fatalities caused by burn injuries is considered to be relatively small, these kinds of accidents continue to happen. Data from the UK shows that in the period 2003–2008, 22 firefighters died on duty, significantly more than in the previous five years. From February 1996 to October 2002, there were no recorded fire deaths in the UK among firefighters who actually attended fires, whereas in the years 2002–2005 13 firefighters were killed at fires. These statistics do not include fatal heart attacks which happened during the emergency intervention, nor road traffic accidents in transit to or from the accident. Statistics on fatal accidents indicate that in the US, 43% of firefighters’ deaths in 2009 were caused by sudden cardiac death, 34% by internal trauma, 6% by asphyxiation, 6% by stroke, 6% by ‘other’ causes, 4% by burns, and 1% by gunshot. The high prevalence of fatalities due to cardiovascular overexertion among firefighters (triggered, for instance, by the emergency alarm that abruptly terminates sedentary activity and begins intense exertion, the very high heart rates recorded during firefighting, exposure to extreme heat, and wearing of heavy protective equipment) has been confirmed by many studies. Also at high risk are emergency medical staff and ambulance personnel. Fatal accidents can occur as an immediate consequence of vehicle-related accidents, homicides (a higher prevalence of this among emergency medical workers compared to other medical staff has been reported), and terrorist attacks (such as the hundreds of emergency workers who died in the aftermath of the 2001 attack at the World Trade Center). In Sweden in 2002, 80% of emergency paramedics reported being threatened or experiencing physical violence. Fatalities are also related to radiological exposure caused by industrial accidents. Out of 237 emergency workers involved in the 1986 disaster at Chernobyl and later diagnosed with acute radiation syndrome (ARS), 28 died from ARS in the following months, and a further 19 in the years afterwards.

Available statistics indicate the significant prevalence of Non-Fatal Accidents and Injuries among emergency workers. For instance, the number of non-fatal accidents suffered by firefighters in Finland ranged between 500 and 600 per year during the period 2005–2007 out of a total population of about 19,000 firefighters. German data shows that accidents while moving, such as being struck or hit by objects, are the most prevalent, following those involving manual handling and dealing with dangerous, sharp, pointed, stiff, or rough-textured objects. In 2004–2005, the most frequent non-fatal accidents among workers in the fire services of the United Kingdom were injuries while handling, lifting or carrying (41.3%), followed by slips, trips or falls on the same level (27.6%) and being hit by a moving, flying or falling object (8.9%). Many other studies confirm that back injuries and upper and lower extremity injuries related to transportation of patients and manual handling are the most common types of injuries experienced by emergency workers, leading to many types of musculoskeletal disorders.

In the last 25 years, the Psychological Trauma suffered by emergency and rescue workers has gained the attention of scientists. Although studies show that the majority of rescue workers may experience stress that does not necessarily lead to diagnosable mental disorders, a variety of symptoms such as strong emotional reactions (shock, anger, guilt, helplessness), cognitive reactions (disorientation, lack of concentration), physical reactions (tension, fatigue, pain, racing heartbeat) and social effects (isolation from family and friends) may for some time after an incident have a negative impact on workers’ wellbeing. More serious problems such as acute stress disorder, depression, anxiety, and post-traumatic stress disorders (PTSD) have also been diagnosed. A Swedish study indicates a prevalence of between 3% and 25% of PTSD among rescue workers there. In the USA, the national prevalence of PTSD for the general population was recorded at 4%, whereas the highest reported prevalence for a particular group was 25% among rescue workers and 21% among firefighters. Higher rates of ‘burnout’ and problems with substance abuse have also been recorded in these groups, compared to the general population.

Occupational Diseases described in the literature are related to the development of different types of cancer as a consequence of radiological exposure, such as the increase in cases of thyroid cancer revealed in a study of Russian emergency workers involved in the Chernobyl disaster. There are also several epidemiological studies which refer to respiratory disorders experienced by emergency workers, including firefighters, rescue workers, clean-up workers, and police officers who were exposed for several months to dust and hazardous toxic pollutants at the WTC disaster scene, showing that WTC-related lower respiratory symptoms were experienced by 60% and upper respiratory symptoms by 74% of the studied sample. Respiratory symptoms include the ‘World Trade Center cough’, a persistent cough that some workers developed after exposure to conditions at the site, and which was accompanied by respiratory symptoms severe enough to require medical leave for at least four weeks. Other serious health problems caused by exposure to hazardous materials and dangerous combustion products include various types of cancer, asbestosis, skin disorders, changes in biochemical and blood parameters, reproductive problems, and even general shorter life expectancy. Many studies, however, show ambiguous results, and further research in this area is needed.

The nature of emergency work makes it impossible to eliminate, or often even significantly reduce, the amount of risk to which personnel are exposed. However, there are many primary and secondary preventive measures which may provide better protection. Some examples of preventive measures at international and national levels include the development of common co-operation and communication procedures, and the introduction of specific laws or policies to protect emergency workers.

Preventive measures at the company level include:

better management (communication and co-ordination) ;
comprehensive risks assessment ;
appropriate preparedness and training (for instance, workers should obtain knowledge about what hazards can be encountered at the disaster scene, the possible physical and mental reactions to them, and how to protect themselves against negative outcomes) ;
vaccination ;
providing appropriate personal protective equipment, protective clothes, safety equipment (for instance, gas detectors, radiation alarm systems, mosquito nets), and ergonomic equipment (firefighter robots, syringe needles that incorporate safety features) ;
providing primary and secondary prevention of mental health problems (psychological preparedness, post-intervention psychological support and help, and long-term psychological care when needed) ;
long-term care and health surveillance alongside mandatory medical examinations, including workplace health promotion projects that provide workers with appropriate and safe keep-fit facilities.

Although major disasters and accidents are always to be expected, past disasters and more recent events demonstrate that communities are still often not fully prepared for dealing with major disasters. It is also clear that the protection of emergency workers against OSH Risks exhibits shortcomings. This literature review indicates some areas in which additional research and actions are necessary. General preventive measures begin with reducing the vulnerability of people to disasters, and reducing the severity of the damage that might be caused by a disaster, resulting in a smaller number of emergency workers needed to take part in disaster control. The OSH of Emergency Workers should be also taken into consideration in the earliest stages of building design, such as by making it possible for lifts to be used during an emergency, and in the formation of emergency response plans at international, national, and organisational level. Rehearsing different terrorist attack scenarios can serve as a way to predict possible hazards for emergency workers. Also essential is the further development of personal protective and other safety equipment, especially against multiple hazards and bio-terrorism, and taking into consideration the possibility of physical overstrain and the difficult working environment of emergency workers. Further longitudinal research on the negative health effects of dangerous substances is needed, including studies on the toxicological properties of the combustion of new products which are constantly being developed and introduced to the market.

EU-OSHA – October 2011

Emergency Services: A Literature Review on Occupational Safety & Health Risks

Click the Link Above to read and/or download PDF File (1.32 Mb)

END

Post-9/11 & Post-Mumbai Fire Engineering – What Future ?

CJ Walsh — Thu, 15 Dec 2011 14:24:20 +0000

Previous Posts in This Series …

2011-10-25: NIST’s Recommendations on the 9-11 WTC Building Collapses … GROUP 1. Increased Structural Integrity – Recommendations 1, 2 & 3 (out of 30)

2011-11-18: NIST WTC Recommendations 4-7 > Structural Fire Endurance … GROUP 2. Enhanced Fire Endurance of Structures – Recommendations 4, 5, 6 & 7

2011-11-24: NIST WTC Recommendations 8-11 > New Design of Structures … GROUP 3. New Methods for Fire Resisting Design of Structures – Recommendations 8, 9, 10 & 11

2011-11-25: NIST WTC Recommendations 12-15 > Improved Active Protection … GROUP 4. Improved Active Fire Protection – Recommendations 12, 13, 14 & 15

2011-11-30: NIST Recommendations 16-20 > Improved People Evacuation … GROUP 5. Improved Building Evacuation – Recommendations 16, 17, 18, 19 & 20

2011-12-04: NIST WTC Recommendations 21-24 > Improved Firefighting … GROUP 6. Improved Emergency Response – Recommendations 21, 22, 23 & 24

2011-12-07: NIST WTC Recommendations 25-28 > Improved Practices … GROUP 7. Improved Procedures and Practices – Recommendations 25, 26, 27 & 28

2011-12-08: NIST WTC Recommendations 29-30 > Improved Fire Education … GROUP 8. Education and Training – Recommendations 29 & 30 (out of 30)

Colour image showing 'The Cloud' Residential Tower Project, in Seoul (South Korea) ... which will be completed in 2015. Design by MVRDV Architects, The Netherlands. Click to enlarge.

2011-12-15: You know what is coming soon … so Merry Christmas & Happy New Year to One and All !!

1. There were 2 Important Reasons for undertaking this Series of Posts …

(a) The General Public, and particularly Client Organizations, should be facilitated in directly accessing the core content of the 2005 NIST WTC Recommendations. Up to now, many people have found this to be a daunting task. More importantly, I also wanted to clearly show that implementation of the Recommendations is still proceeding far too slowly … and that today, many significant aspects of these Recommendations remain unimplemented. Furthermore, in the case of some recent key national standards, e.g. British Standard BS 9999, which was published in 2008 … the NIST Recommendations were entirely ignored.

As a golden rule … National Building Codes/Regulations and National Standards … cannot, should not, and must not … be applied without informed thought and many questions, on the part of a building designer !

(b) With the benefit of hindsight, and our practical experience in FireOx International … I also wanted to add a necessary 2011 Technical Commentary to the NIST Recommendations … highlighting some of the radical implications, and some of the limitations, of these Recommendations … in the hope of initiating a much-needed and long overdue international discussion on the subject.

Colour photograph showing the Taipei 101 Tower, in Taiwan ... which was completed in 2004. Designed by C.Y. Lee & Partners Architects/Planners, Taiwan. Click to enlarge.

” Architecture is the language of a culture.”

” A living building is the information space where life can be found. Life exists within the space. The information of space is then the information of life. Space is the body of the building. The building is therefore the space, the information, and the life.”

C.Y. Lee & Partners Architects/Planners, Taiwan

[ This is a local dialect of familiar Architectural Language. However, the new multi-aspect language of Sustainable Design is fast evolving. In order to perform as an effective and creative member of a Trans-Disciplinary Design & Construction Team ... can Fire Engineers quickly learn to communicate on these wavelengths ?? Evidence to date suggests not ! ]

2. ‘Climate Change’ & ‘Energy Stability’ – Relentless Driving Forces for Sustainable Design !

Not only is Sustainable Fire Engineering inevitable … it must be ! And not at some distant point in the future … but now … yesterday !! There is such a build-up of pressure on Spatial Planners and Building Designers to respond quickly, creatively, intuitively and appropriately to the relentless driving forces of Climate Change (including climate change mitigation, adaptation, and severe weather resilience) and Energy Stability (including energy efficiency and conservation) … that there is no other option for the International Fire Science and Engineering Community but to adapt. Adapt and evolve … or become irrelevant !!

And one more interesting thought to digest … ‘Green’ is not the answer. ’Green’ looks at only one aspect of Sustainable Human & Social Development … the Environment. This is a blinkered, short-sighted, simplistic and ill-conceived approach to realizing the complex goal of a Safe and Sustainable Built Environment. ‘Green’ is ‘Sustainability’ for innocent children !!

Colour image showing the Shanghai Tower Project, in China ... which will be completed in 2014. Design by Gensler Architects & Planners, USA. Click to enlarge.

(a) Organization for Economic Co-Operation & Development (OECD) – 2012′s Environmental Outlook to 2050

Extract from Pre-Release Climate Change Chapter, November 2011 …

‘ Climate change presents a global systemic risk to society. It threatens the basic elements of life for all people: access to water, food production, health, use of land, and physical and natural capital. Inadequate attention to climate change could have significant social consequences for human wellbeing, hamper economic growth and heighten the risk of abrupt and large-scale changes to our climatic and ecological systems. The significant economic damage could equate to a permanent loss in average per capita world consumption of more than 14% (Stern, 2006). Some poor countries would be likely to suffer particularly severely. This chapter demonstrates how avoiding these economic, social and environmental costs will require effective policies to shift economies onto low-carbon and climate-resilient growth paths.’

(b) U.N. World Meteorological Organization (WMO) Greenhouse Gas Bulletin No.7, November 2011

Executive Summary …

The latest analysis of observations from the WMO Global Atmosphere Watch (GAW) Programme shows that the globally averaged mixing ratios of Carbon Dioxide (CO₂), Methane (CH₄) and Nitrous Oxide (N₂O) reached new highs in 2010, with CO₂ at 389.0 parts per million (ppm), CH₄ at 1808 parts per billion (ppb) and N₂O at 323.2 ppb. These values are greater than those in pre-industrial times (before 1750) by 39%, 158% and 20%, respectively. Atmospheric increases of CO₂ and N₂O from 2009 to 2010 are consistent with recent years, but they are higher than both those observed from 2008 to 2009 and those averaged over the past 10 years. Atmospheric CH₄ continues to increase, consistent with the past three years. The U.S. National Oceanic & Atmospheric Administration (NOAA) Annual Greenhouse Gas Index shows that from 1990 to 2010 radiative forcing by long-lived Greenhouse Gases (GHG’s) increased by 29%, with CO₂ accounting for nearly 80% of this increase. Radiative forcing of N₂O exceeded that of CFC-12, making N₂O the third most important long-lived Greenhouse Gas.

(c) International Energy Agency (IEA) – World Energy Outlook, November 2011

Extract from Executive Summary …

‘ There are few signs that the urgently needed change in direction in global energy trends is underway. Although the recovery in the world economy since 2009 has been uneven, and future economic prospects remain uncertain, global primary energy demand rebounded by a remarkable 5% in 2010, pushing CO₂ emissions to a new high. Subsidies that encourage wasteful consumption of fossil fuels jumped to over $400 billion. The number of people without access to electricity remained unacceptably high at 1.3 Billion, around 20% of the world’s population. Despite the priority in many countries to increase energy efficiency, global energy intensity worsened for the second straight year. Against this unpromising background, events such as those at the Fukushima Daiichi Nuclear Power Plant and the turmoil in parts of the Middle East and North Africa (MENA) have cast doubts on the reliability of energy supply, while concerns about sovereign financial integrity have shifted the focus of government attention away from energy policy and limited their means of policy intervention, boding ill for agreed global climate change objectives.’

Colour image showing the One World Trade Center Project, in New York City (USA) ... which will be completed in 2013. Design by Skidmore Owings & Merrill, Architects/Planners, USA. Click to enlarge.

[ Not just in the case of Tall, Super-Tall and Mega-Tall Buildings ... but the many, many Other Building Types in the Built Environment ... are Building Designers implementing the 2005 & 2008 NIST WTC Recommendations ... without waiting for Building and Fire Codes/Regulations and Standards to be properly revised and updated ?? Evidence to date suggests not ! ]

3. Separate Dilemmas for Client Organizations and Building Designers …

As discussed earlier in this Series … the Fire Safety Objectives of Building and Fire Codes/Regulations are limited to:

The protection of building users/occupants ; and
The protection of property … BUT only insofar as that is relevant to the protection of the users/occupants ;

… because the function of Building and Fire Codes is to protect Society. Well, that is supposed to be true ! Unfortunately, not all Codes/Regulations are adequate or up-to-date … as we have been observing here in these posts.

Just taking the Taipei 101 Tower as an example, I have very recently sent out three genuine, bona fide e-mail messages from our practice …

2011-12-08

Toshiba Elevator & Building Systems Corporation (TELC), Japan.

To Whom It May Concern …

Knowing that your organization was involved in the Taipei 101 Project … we have been examining your WebSite very carefully. However, some important information was missing from there.

For our International Work … we would like to receive technical information on the Use of Elevators for Fire Evacuation in Buildings … which we understand is actually happening in the Taipei Tower, since it was completed in 2004.

The Universal Design approach must also be integrated into any New Elevators.

Can you help us ?

C.J. Walsh

[2012-01-10 ... No reply yet !]

2011-12-12

Mr. Thomas Z. Scarangello P.E. – Chairman & CEO, Thornton Tomasetti Structural Engineers, New York.

Dear Thomas,

Knowing that your organization was involved in the structural design of the Taipei 101 Tower, which was completed in 2004 … and in the on-going design of many other iconic tall, super-tall and mega-tall buildings around the world … we have been examining your Company Brochures and WebSite very carefully. However, some essential information is missing.

As you are certainly aware … implementation of the 2005 & 2008 National Institute of Standards & Technology (NIST) Recommendations on the Collapse of WTC Buildings 1, 2 & 7, in New York, on 11 September 2001 … is still proceeding at a snail’s pace, i.e. very slowly. Today, many significant aspects of NIST’s Recommendations remain unimplemented.

For our International Work … we would like to understand how you have responded directly to the NIST Recommendations … and incorporated the necessary additional modifications into your current structural fire engineering designs.

Many thanks for your kind attention. In anticipation of your prompt and detailed response …

C.J. Walsh

[2012-01-10 ... No reply yet !]

2011-12-14

Mr. C.Y. Lee & Mr. C.P. Wang, Principal Architects – C.Y. Lee & Partners Architects/Planners, Taiwan.

Dear Sirs,

Knowing that your architectural practice designed the Taipei 101 Tower, which was completed in 2004 … and, later, was also involved in the design of other tall and super-tall buildings in Taiwan and China … we have been examining your Company WebSite very carefully. However, some essential information is missing.

As you are probably aware … implementation of the 2005 & 2008 U.S. National Institute of Standards & Technology (NIST) Recommendations on the Collapse of WTC Buildings 1, 2 & 7, in New York City, on 11 September 2001 … is still proceeding at a snail’s pace, i.e. very slowly. Today, many significant aspects of NIST’s Recommendations remain unimplemented.

Many thanks for your kind attention. In anticipation of your prompt and detailed response …

C.J. Walsh

[2012-01-10 ... No reply yet !]

So … how many Clients, or Client Organizations, are aware that to properly protect their interests … even, a significant part of their interests … it is vitally necessary that Project-Specific Fire Engineering Design Objectives be developed which will have a much wider scope ? The answer is … not many !

How many Architects, Structural Engineers, and Fire Engineers fully explain this to their Clients or Client Organizations ?

And how many Clients/Client Organizations either know that they should ask, or have the balls to ask … their Architect, Structural Engineer and Fire Engineer for this explanation … and furthermore, in the case of any High-Rise Building, Iconic Building, or Building having an Important Function or an Innovative Design … ask the same individuals for some solid reassurance that they have responded directly to the 2005 & 2008 NIST WTC Recommendations … and incorporated the necessary additional modifications into your current designs … whatever current Building and Fire Codes/Regulations do or do not say ?? A big dilemma !

A common and very risky dilemma for Building Designers, however, arises in the situation where the Project Developer, i.e. the Client/Client Organization … is the same as the Construction Organization. The Project Design & Construction Team - as a whole - now has very little power or authority if a conflict arises over technical aspects of the design … or over construction costs. An even bigger dilemma !!

Colour image showing the Kingdom Tower Project, in Jeddah (Saudi Arabia) ... which will be completed in 2018. Design by Adrian Smith & Gordon Gill Architecture, USA. Click to enlarge.

4. The Next Series of Posts – 2008 NIST WTC Recommendations

In the new year of 2012 … I will examine the later NIST Recommendations which were a response to the Fire-Induced Progressive Collapse of World Trade Center Building No.7.

Colour image showing the Signature Tower Project, in Jakarta (Indonesia) ... which will be completed in 2016. Design by Smallwood Reynolds Stewart Stewart Architects & Planners, USA. Click to enlarge.

5. Please … Your Comments, Views & Opinions ?!?

The future of Conventional Fire Engineering ended on the morning of Tuesday, 11 September 2001, in New York City … an engineering discipline constrained by a long heritage deeply embedded in, and manacled to, an outdated and inflexible prescriptive approach to Codes/Regulations and Standards … an approach which is irrational, ignores the ‘real’ needs of the ‘real’ people who use and/or occupy ‘real’ buildings … and, quite frankly, no longer makes any scientific sense !!

On the other hand … having confronted the harsh realities of 9/11 and the Mumbai ‘Hive’ Attacks, and digested the 2005 & 2008 NIST WTC Recommendations … Sustainable Fire Engineering … having a robust empirical basis, being ‘person-centred’, and positively promoting creativity … offers the International Fire Science and Engineering Community a confident journey forward into the future … on many diverse routes !

This IS the only appropriate response to the exciting architectural innovations and fire safety challenges of today’s Built Environment.

BUT … what do you think ?

END

NIST WTC Recommendations 29-30 > Improved Fire Education

CJ Walsh — Thu, 08 Dec 2011 21:51:43 +0000

Previous Posts in This Series …

2011-10-25: NIST’s Recommendations on the 9-11 WTC Building Collapses … GROUP 1. Increased Structural Integrity – Recommendations 1, 2 & 3 (out of 30)

2011-11-18: NIST WTC Recommendations 4-7 > Structural Fire Endurance … GROUP 2. Enhanced Fire Endurance of Structures – Recommendations 4, 5, 6 & 7

2011-11-24: NIST WTC Recommendations 8-11 > New Design of Structures … GROUP 3. New Methods for Fire Resisting Design of Structures – Recommendations 8, 9, 10 & 11

2011-11-25: NIST WTC Recommendations 12-15 > Improved Active Protection … GROUP 4. Improved Active Fire Protection – Recommendations 12, 13, 14 & 15

2011-11-30: NIST Recommendations 16-20 > Improved People Evacuation … GROUP 5. Improved Building Evacuation – Recommendations 16, 17, 18, 19 & 20

2011-12-04: NIST WTC Recommendations 21-24 > Improved Firefighting … GROUP 6. Improved Emergency Response – Recommendations 21, 22, 23 & 24

2011-12-07: NIST WTC Recommendations 25-28 > Improved Practices … GROUP 7. Improved Procedures and Practices – Recommendations 25, 26, 27 & 28

2011-12-08: SOME PRELIMINARY COMMENTS …

1. At last, we arrive at the Group 8 Recommendations ! At this stage … my impression is that the NIST Team began to run out of steam, because these two short Recommendations barely scratch the surface with regard to the significant education and training needs of the many different design, construction, management, operation, maintenance and emergency response disciplines engaged with, and confronted by, the Built Environment … every day of every week.

After a careful reading of all 30 NIST WTC Recommendations, I hope that you have satisfied yourself/yourselves that these Recommendations must be applied to ALL Buildings … not just Tall Buildings. At various times … Iconic Buildings, and Buildings having a Critical Function or an Innovative Design have been specifically mentioned. And look back to Recommendation 22a … tunnels and subways also made an appearance ! The proper focus for the International Fire Science and Engineering Community must be on the Built Environment as a whole.

At All Levels in a Typical Construction Project … there are also pressing education and training needs. It is of little use if the Project Design Documentation is 100% … and the people actually installing the passive fire protection measures or the active fire protection systems on site don’t know which end is ‘up’ ! The Project Design Documentation, in whatever format, is merely a means to an end … a fully realized and occupied Building, which is fire-safe.

Preferably … we should be discussing the mandatory Re-education and Re-training of Practitioners in the different Disciplines … [CPD (Continuing Professional/Personal Development) is not at all sufficient !] … accompanied by a very necessary Re-engineering of the Stakeholder Professional and Educational Institutions … and other related Organizations, particularly National Authorities Having Jurisdiction (AHJ’s).

Our Best Hope for Transformation … lies with the current crop of third-level undergraduate students in the different disciplines. And, as we are discovering with the introduction of the Structural EuroCodes in the European Union, it will take perhaps 5-8 years of continuous student output to transform pre-9/11 conventional fire engineering … into a post-9/11 and post-Mumbai fire engineering which is properly ‘reliability-based’ and ‘person-centred’, i.e. Sustainable Fire Engineering !

As for the Future, and Some Conclusions to this Series … coming shortly to a computer monitor screen near you !

2005 NIST WTC RECOMMENDATIONS

GROUP 8. Education and Training

NIST WTC Recommendation 29.

NIST WTC Recommendation 30.

END

NIST WTC Recommendations 25-28 > Improved Practices

CJ Walsh — Wed, 07 Dec 2011 17:47:01 +0000

Previous Posts in This Series …

2011-10-25: NIST’s Recommendations on the 9-11 WTC Building Collapses … GROUP 1. Increased Structural Integrity – Recommendations 1, 2 & 3 (out of 30)

2011-11-18: NIST WTC Recommendations 4-7 > Structural Fire Endurance … GROUP 2. Enhanced Fire Endurance of Structures – Recommendations 4, 5, 6 & 7

2011-11-24: NIST WTC Recommendations 8-11 > New Design of Structures … GROUP 3. New Methods for Fire Resisting Design of Structures – Recommendations 8, 9, 10 & 11

2011-11-25: NIST WTC Recommendations 12-15 > Improved Active Protection … GROUP 4. Improved Active Fire Protection – Recommendations 12, 13, 14 & 15

2011-11-30: NIST Recommendations 16-20 > Improved People Evacuation … GROUP 5. Improved Building Evacuation – Recommendations 16, 17, 18, 19 & 20

2011-12-04: NIST WTC Recommendations 21-24 > Improved Firefighting … GROUP 6. Improved Emergency Response – Recommendations 21, 22, 23 & 24

2011-12-07: SOME PRELIMINARY COMMENTS …

1. Concerning Recommendation 25 below … yes, this Recommendation applies to the types of organizations identified in the text, but it should also be understood as applying to ALL Organizations … public or private, governmental or non-governmental or quasi-governmental, whatever, etc … ‘supported’ (see the text further down in Recommendation 25) with rigorous enforcement, in all cases, by publically appointed building control officials and/or by private, independent, competent technical control professionals.

Once more … and again and again (!) … confirmed by the sort of debacle seen at the Priory Hall Apartment Complex, in Dublin … Self-Certification / Self-Approval, i.e. ‘lite’ regulation, does not work. For National Authorities Having Jurisdiction (AHJ’s), however, it is a cheap solution to a difficult, resource-devouring issue, i.e. protecting society and the consumer … in that order.

2. Concerning the Footnote to Recommendation 26 below … the choice should never be between either Fire Compartmentation or Sprinklers … or the other way around, whichever you prefer. Neither is 100% reliable !

Fire Compartmentation

The division of a building into fire-tight compartments, by fire and smoke resisting elements of construction, in order …

to contain an outbreak of fire, and to facilitate effective firefighting ;
to prevent damage, within the building, to other adjoining compartments and/or spaces ;
to protect a compartment interior from external fire attack, e.g. fire spread across the building’s facade or from an adjacent building ;
to minimize adverse, or harmful, environmental impacts outside the building.

As developed as that definition is above, Fire Compartmentation should be regarded as just one Fire Safety Strategy / Fire Engineering Strategy … not the only strategy, and certainly not the main strategy.

Here are two reasons why not …

a) The connection between compartment size and the ability to effectively fight a fire within a space of limited volume has been lost … so more and more, commercial pressure is being exerted on national authorities to expand the acceptable compartment sizes in buildings … which significantly increases the fire hazard ;

[ Remembering the difference between the limited Fire Safety Objectives of Building Codes/Regulations and the much broader Project-Specific Fire Engineering Objectives of Ethical Fire Engineering required to protect society and the full interests of our clients ... it is easy to understand why national authorities feel that they can respond positively to such commercial pressures.]

b) In a Sustainable Building … it is a very common design strategy to take advantage of the natural patterns of air movement in a building, for either cooling or heating purposes, depending on local climate conditions. So there is simply no compartmentation, as understood in conventional fire engineering terms … and this throws up a fundamental conflict between the two. To be discussed in another post !

3. Concerning the 2nd Footnote to Recommendation 28 below … in the very same New York City … at 09.40 hrs on a Saturday morning, 28 July 1945 … lost in fog, a B-25 Bomber slammed head-on into the 79th Floor of the Empire State Building … and caused enormous damage. That building is still standing today … and surprise, surprise … there was aviation fuel in the B-25 !

In a similar vein … Fire-Induced Progressive Collapse was not observed for the first time, in New York, on 11 September 2001 !

2005 NIST WTC RECOMMENDATIONS

GROUP 7. Improved Procedures and Practices

The procedures and practices used in the design, construction, maintenance, and operation of buildings should be improved to include encouraging code compliance by non-governmental and quasi-governmental entities, adoption and application of egress and sprinkler requirements in codes for existing buildings, and retention and availability of building documents over the life of a building.

NIST WTC Recommendation 25.

Non-governmental and quasi-governmental entities that own or lease buildings and are not subject to building and fire safety code requirements of any governmental jurisdiction are nevertheless concerned about the safety of building occupants and responding emergency personnel. NIST recommends that such entities be encouraged to provide a level of safety that equals or exceeds the level of safety that would be provided by strict compliance with the code requirements of an appropriate governmental jurisdiction. NIST further recommends that as-designed and as-built safety be certified by a qualified third party, independent of the building owner(s). The process should not use self-approval for code enforcement in areas including interpretation of code provisions, design approval, product acceptance, certification of the final construction, and post-occupancy inspections over the life of the buildings.*

[ * F-46 The long-standing stated policy of the Port Authority of New York & New Jersey (PANYNJ) was to meet and, where appropriate, exceed the requirements of local building and fire codes, and it entered into agreements with the New York City Department of Buildings and the Fire Department of the City of New York in accordance with that policy. Although the PANYNJ sought review and concurrence from New York City in the areas listed in the Recommendation, the PANYNJ was not required to yield, and appears not to have yielded, approval authority to New York City. The PANYNJ was created as an interstate entity, a 'body corporate and politic', under its charter, pursuant to Article 1, Section 10 of the United States Constitution permitting compacts between states. Further, there are many other similar non-governmental and quasi-governmental entities in the U.S. A comprehensive review of documents conducted as part of this Investigation suggests that the WTC towers generally were designed and maintained consistent with the requirements of the 1968 New York City Building Code. Areas of concern included fireproofing of the WTC floor system, height of tenant separation walls, and egress requirements for the assembly use spaces of 'Windows of the World' in WTC Tower 1 and the 'Top of the World' Observation Deck in WTC Tower 2. These areas of concern did not play a significant role in determining the outcomes related to the events on 11th September 2001.]

NIST WTC Recommendation 26.

NIST recommends that state and local jurisdictions adopt and aggressively enforce available provisions in building codes to ensure that egress and sprinkler requirements are met by existing buildings.* Further, occupancy requirements should be modified where needed (such as when there are assembly use spaces within an office building) to meet the requirements in model building codes. Provisions related to egress and sprinkler requirements in existing buildings are available in such codes as the International Existing Building Code (IEBC), International Fire Code, NFPA 1, NFPA 101, and ASME A 17.3. For example, the IEBC defines three levels of building alteration (removal and replacement or covering of existing materials and equipment, reconfiguration of space or system or installation of new equipment, and extending the work area in excess of 50% of the aggregate area of the building). At the lowest level, there are no upgrade implications for sprinklers and the egress system. At the next level, sprinklers are required in work areas serving greater than 30 people if certain other conditions related to building height and use such as shared exits also are met. There are numerous requirements for means of egress, including number of exits, specification of doorsets, dead-end corridors and travel distances, lighting, signage, and handrails. At the highest level, the sprinkler and egress requirements are identical to the second level without the minimum 30-person restriction and the other conditions related to building height and use. The Life Safety Code (NFPA 101) applies retroactively to all buildings, independent of whether any work is currently being done on the building, and ASME A 17.3 applies retroactively to all elevators as a minimum set of requirements.

[ * F-47 The WTC towers were unsprinklered when built. It took nearly 28 years after passage of New York City Local Law 5 in 1973, which required either compartmentation or sprinklering, for the buildings to be fully sprinklered (the Port Authority chose not to use the compartmentation option in Local Law 5). This was about 13 years more than the 15-year period for full compliance with Local Law 5 that was set by Local Law 84 of 1979.]

NIST WTC Recommendation 27.

[ * F-48 The availability of inexpensive electronic storage media and tools for creating large searchable databases makes this feasible.]

NIST WTC Recommendation 28.

NIST recommends that the role of the ‘Design Professional in Responsible Charge’* be clarified to ensure that: (1) all appropriate design professionals (including, e.g. the fire protection engineer) are part of the design team providing the highest standard of care when designing buildings employing innovative or unusual fire safety systems;** and (2) all appropriate design professionals (including, e.g. the structural engineer and the fire protection engineer) are part of the design team providing the highest standard of care when designing the structure to resist fires, in buildings that employ innovative or unusual structural and fire safety systems. Affected Standards: AIA Practice Guidelines. Model Building Codes: The International Building Code (IBC), which already defines ‘Design Professional in Responsible Charge’, should be clarified to address this Recommendation. NFPA 5000 should incorporate the ‘Design Professional in Responsible Charge’ concept, and address this Recommendation.

[ * F-49 In projects involving a design team, the 'Design Professional in Responsible Charge' - usually the lead architect - ensures that the team members use consistent design data and assumptions, co-ordinates overlapping specifications, and serves as the liaison between the enforcement and reviewing officials and the owner. This term is defined in the International Building Code (IBC) and in the International Code Council's Performance Code for Buildings and Facilities (where it is the Principal Design Professional).]

[ ** F-50 If the fire safety concepts in tall buildings had been sufficiently mature in the 1960's, it is possible that the risks associated with jet-fuel ignited multi-floor fires might have been recognized and taken into account when the impact of a Boeing 707 aircraft was considered by the structural engineer during the design of the WTC towers.]

END

NIST Recommendations 16-20 > Improved People Evacuation

CJ Walsh — Wed, 30 Nov 2011 18:01:08 +0000

Previous Posts in This Series …

2011-10-25: NIST’s Recommendations on the 9-11 WTC Building Collapses … GROUP 1. Increased Structural Integrity – Recommendations 1, 2 & 3 (out of 30)

2011-11-18: NIST WTC Recommendations 4-7 > Structural Fire Endurance … GROUP 2. Enhanced Fire Endurance of Structures – Recommendations 4, 5, 6 & 7

2011-11-24: NIST WTC Recommendations 8-11 > New Design of Structures … GROUP 3. New Methods for Fire Resisting Design of Structures – Recommendations 8, 9, 10 & 11

2011-11-25: NIST WTC Recommendations 12-15 > Improved Active Protection … GROUP 4. Improved Active Fire Protection – Recommendations 12, 13, 14 & 15

2011-11-30: SOME PRELIMINARY COMMENTS …

1. In the First Post of this Series, I wrote …

” As such a high level of performance is expected … indeed demanded … of a Sustainable Building … Sustainable Fire Engineering must be ‘reliability-based’ … in other words, it must have a rational, empirical and scientifically robust basis … “

Sustainable Fire Engineering must also be ‘person-centred’ … i.e. a design process (in whatever architectural or engineering discipline) which places ‘real’ people at the centre of creative endeavours and gives due consideration to their responsible needs, and their health, safety, welfare and security in the Human Environment.

In order to prolong, and if at all possible, significantly extend the Life Cycle of a Sustainable Building beyond 100 years … Fire Engineers must begin to feel at ease … and be comfortable … with the following mainstream Sustainable Design Concepts …

Flexibility: The extent to which a building interior is designed, when new, to be capable of being easily modified at any later stage during the life cycle of that building – with minimal cost and user inconvenience – because of a person’s changing living or working needs.

Adaptability: The extent to which a building, or a building component, is designed when new, or capable of being easily modified at any later stage, to meet the changing life and living needs of the broad range of potential users, who may or may not have activity limitations, or may develop a health condition during the life cycle of that building or component.

Accessibility of a Building: Ease of independent approach, entry, egress (during normal ambient conditions), evacuation (in the event of an emergency) and/or use of a building and its services and facilities, by all of the building’s potential users - with an assurance of individual health, safety and welfare during the course of those activities.

2. Group 5 of the 2005 NIST WTC Recommendations is, by far, the most important … introducing some innovative concepts of ‘real’ evacuation … with nothing too startling. Contrary to the impression given by NIST … these Recommendations are equally valid for complex building types and, in reality, for all but the most simple of low-rise buildings. It is interesting to note, however, that when discussing fire behaviour or structural performance in fire, for example … the NIST texts are confident and direct. Here, when dealing with ‘people’ issues … not so confident, prone to some rambling … and lacking clarity.

Shortly after the 2005 NIST Report (NCSTAR 1) was published, I stated the following on the SDI Corporate WebSite … at this FireOx International Page … http://www.sustainable-design.ie/fire/structdesfire.htm …

” In its treatment of ‘disability’ and ‘people with activity limitations’, the Report does not go far enough, and is seriously flawed.”

Let me explain why …

As you go scan down through NIST’s Recommendations 16-20, you will encounter 1 reference to ‘mobility impaired occupants’ and 2 references to the impersonal ‘mobility impaired’. IF (and that is still a very big ‘if’, because there is still so much rabid resistance to this topic !) … a New Post-9/11 Evacuation Model, or Construct, Dealing with ‘Disability’ is being developed … all of the major impairment groupings (i.e. visual impairment, hearing impairment, physical function impairment, mental/cognitive impairment, and psychological impairment) must be added to the mix from the beginning. In other words, our proper focus of attention must be ‘people with activity limitations’ … not just people with disabilities, but also frail older people (not all older people !), children under the age of 5 years, women in the later stages of pregnancy, people with a health condition, etc.

And … because of the social stigma still firmly attaching to ‘disability’ … many building occupants/users will not self-identify … not even if their lives depend on it !

Concentrating on one group only, i.e. people with mobility impairments, is simplistic and entirely inadequate … and we will all end up, in a few years time, having to graft on a consideration of the other impairment groups.

This is exactly what has already gone wrong with the development of Accessibility Design Guidance during the last 30 years … where ‘people with visual or hearing impairments’ received merely token attention … and ‘people with cognitive or psychological impairments’ received no attention at all ! And … we are now grappling with the challenge of having to graft on additional texts to try to re-balance International Design Guidance on Accessibility of the Built Environment. Been there – done that – I have all of the t-shirts !!

People with Activity Limitations (English) / Personnes à Performances Réduites (French): Those people, of all ages, who are unable to perform, independently and without aid, basic human activities or tasks – because of a health condition or physical/mental/cognitive/psychological impairment of a permanent or temporary nature.

The above Terms (in English and French) include …

wheelchair users ;
people who experience difficulty in walking, with or without a facilitation aid, e.g. stick, crutch, calliper or walking frame ;
frail, older people ;
the very young (people under the age of 5 years) ;
people who suffer from arthritis, asthma, or a heart condition ;
the visually and/or hearing impaired ;
people who have a cognitive impairment disorder, including dementia, amnesia, brain injury, or delirium ;
women in the later stages of pregnancy ;
people impaired following the use of alcohol, other ‘social’ drugs e.g. cocaine and heroin, and some medicines ;
people who suffer any partial or complete loss of language related abilities, i.e. aphasia ;
people impaired following exposure to environmental pollution and/or other irresponsible human activities, e.g. war and terrorism ;

and …

people who experience a panic attack in a fire situation or other emergency ;
people, including firefighters, who suffer incapacitation as a result of exposure, during a fire, to poisonous or toxic substances, and/or elevated temperatures.

3. So … what provision should be made for ‘people with activity limitations’ in typical Fire Engineering Design Projects ?

Equivalent to the concept of Maximum Credible Fire Scenario, which has already been discussed in this Series … at FireOx International, some years ago, we developed the concept of …

Maximum Credible User Scenario

Representing building user conditions which are also severe but reasonable to anticipate …

a) 10% of People Using the Building (occupants, visitors and other users) have an Impairment (visual or hearing, physical function, mental or cognitive, psychological, with some impairments not being identifiable) ;

[ This performance indicator appears in ISO FDIS 21542: 'Building Construction - Accessibility & Usability of the Built Environment', which will soon be published.]

b) The Number of People Using a Building increases, on occasions which cannot be specified, to 120% of designed/calculated maximum building capacity.

[ Generally ... the fire safety related texts contained in ISO 21542 are based on the 2005 & 2008 NIST WTC Recommendations.]

4. With regard to Recommendation 17 below, and NIST’s reference to the widths of evacuation staircases and door openings, etc … fire codes and regulations, fire authorities having jurisdiction (AHJ’s), and even the fire services themselves … still have a crazy mixed-up approach to defining the width of these building features … an approach which I am not even going to attempt to repeat ! Forget it !!

Without Exception … all understandings of Evacuation Route Width, Evacuation Staircase Width and Evacuation Door Opening Width … must be harmonized with the following definitions of Unobstructed Width …

Unobstructed Width – General

Free, unobstructed space – clear of all obstacles below a height of 2.1 metres above finished floor level – necessary for passage along a circulation route, or other route component, e.g. a staircase.

[ For example ... the Unobstructed Width of a Staircase is the clear dimension from the edge of one handrail to the edge of the opposite handrail ... and there is always a continuous handrail on each side of an evacuation staircase ! ]

Unobstructed Width – Door Opening

Free, unobstructed space – clear of all obstacles below a height of 2.0 metres above finished floor level – necessary for passage through a door opening, measured when the door leaf is opened to an angle of 90°, or when a sliding or folding door leaf is opened to its fullest extent.

[ For example ... the Unobstructed Width of a Door Opening is the dimension from the edge of the door leaf (when open at an angle of 90°) to the nearest edge of the door frame.]

This FireOx International Page on the SDI Corporate WebSite provides more guidance … http://www.sustainable-design.ie/fire/appendixd.htm

5. With regard to Recommendation 20 below, and NIST’s reference to allowing “all occupants an equal opportunity for evacuation” … this is not just a ‘nice idea’, or an ‘idealistic notion’ … this is now a Human and Social Right which is backed up and supported by International Law ! And … it is no longer acceptable for the Fire Science and Engineering Community to continue its stubborn resistance in the face of this fact !!

For the benefit of my fire engineering colleagues … I will, once again here, reproduce the most relevant extracts from the United Nations Convention on the Rights of Persons with Disabilities …

UN CRPD Preamble Paragraph (g)

Emphasizing the importance of mainstreaming disability issues as an integral part of relevant strategies of sustainable development, …

UN CRPD Article 9 – Accessibility

1. To enable persons with disabilities to live independently and participate fully in all aspects of life, States Parties shall take appropriate measures to ensure to persons with disabilities access, on an equal basis with others, to the physical environment, to transportation, to information and communications, including information and communications technologies and systems, and to other facilities and services open or provided to the public, both in urban and in rural areas. These measures, which shall include the identification and elimination of obstacles and barriers to accessibility, shall apply to, inter alia:

(a) Buildings, roads, transportation and other indoor and outdoor facilities, including schools, housing, medical facilities and workplaces ;

(b) Information, communications and other services, including electronic services and emergency services.

2. States Parties shall also take appropriate measures:

(a) To develop, promulgate and monitor the implementation of minimum standards and guidelines for the accessibility of facilities and services open or provided to the public ;

(b) To ensure that private entities that offer facilities and services which are open or provided to the public take into account all aspects of accessibility for persons with disabilities ;

(c) To provide training for stakeholders on accessibility issues facing persons with disabilities ;

(d) To provide in buildings and other facilities open to the public signage in Braille and in easy to read and understand forms ;

(e) To provide forms of live assistance and intermediaries, including guides, readers and professional sign language interpreters, to facilitate accessibility to buildings and other facilities open to the public ;

(f) To promote other appropriate forms of assistance and support to persons with disabilities to ensure their access to information ;

(g) To promote access for persons with disabilities to new information and communications technologies and systems, including the Internet ;

(h) To promote the design, development, production and distribution of accessible information and communications technologies and systems at an early stage, so that these technologies and systems become accessible at minimum cost.

UN CRPD Article 11 – Situations of Risk & Humanitarian Emergencies

States Parties shall take, in accordance with their obligations under international law, including international humanitarian law and international human rights law, all necessary measures to ensure the protection and safety of persons with disabilities in situations of risk, including situations of armed conflict, humanitarian emergencies and the occurrence of natural disasters.

[ Note: An outbreak of fire in a building is a situation of serious risk for all vulnerable building occupants/users.]

At the time of writing, 153 Countries had signed the UN CRPD … while 106 Countries have ratified the Convention and are, therefore, the ‘State Parties’ referred to above.

These are just a few of the State Parties to the UN CRPD …

Argentina (ratified the UN CRPD, 2008-09-02)
Australia (ratified the UN CRPD, 2008-07-17)
Brazil (ratified the UN CRPD, 2008-08-01)
Canada (ratified the UN CRPD, 2010-03-11)
China (ratified the UN CRPD, 2008-08-01)
Cuba (ratified the UN CRPD, 2007-09-06)
European Union (ratified the UN CRPD, 2010-12-23)
India (ratified the UN CRPD, 2007-10-01)
Malaysia (ratified the UN CRPD, 2010-07-19)
Mexico (ratified the UN CRPD, 2007-12-17)
Philippines (ratified the UN CRPD, 2008-04-15)
South Africa (ratified the UN CRPD, 2007-11-30)
Turkey (ratified the UN CRPD, 2009-09-28)
United Arab Emirates (ratified the UN CRPD, 2010-03-19)

I wonder how implementation is proceeding in these countries !?!

2005 NIST WTC RECOMMENDATIONS

GROUP 5. Improved Building Evacuation

Building evacuation should be improved to include system designs that facilitate safe and rapid egress, methods for ensuring clear and timely emergency communications to occupants, better occupant preparedness regarding their roles and duties for evacuation during emergencies, and incorporation of appropriate egress technologies.*

[ * F-36 This effort should include standards and guidelines for the development and evaluation of emergency evacuation plans, including best practices for both partial and full evacuation, and the development of contingency plans that account for expected conditions that may require adaptation, including the compromise of all or part of an egress path before or during evacuation, or conditions such as widespread power failure, earthquake, or security threat that restrict egress from the building. Evacuation planning should include the process from initial notification of the need to evacuate up to the point when occupants arrive at a place where their safety is ensured. These standards and guidelines should be suitable for assessing the adequacy of evacuation plans submitted for approval, and should require occupant training through the conduct of regular drills.]

NIST WTC Recommendation 16.

NIST recommends that public agencies, non-profit organizations concerned with building and fire safety, and building owners and managers develop and carry out public education and training campaigns, jointly and on a nationwide scale, to improve building occupants’ preparedness for evacuation in case of building emergencies. This effort should include better training and self-preparation of occupants, an effectively implemented system of floor wardens and building safety personnel, and needed improvements to standards. Occupant preparedness should include:

a. Improved training and drills for building occupants to ensure that they know evacuation procedures for a variety of emergency scenarios (e.g. including evacuation and shelter in place), are familiar with the egress route, and are sufficiently aware of what is necessary if evacuation is required with minimal notice (e.g. footwear consistent with the distance to be travelled, a flashlight/glow stick for pathway illumination, and dust masks).

b. Building owners and managers should educate tenants on the life safety systems present in their building(s), provide training materials explaining egress routes and stairwell and elevator information, and develop educational programmes explaining the most appropriate responses in emergency situations. It is further recommended that the owners and managers of office buildings implement the necessary systems for collecting and storing the training history of each building occupant.

c. Improved training and drills that routinely inform building occupants that roof rescue is not (or is) presently feasible as a standard evacuation option, that they should evacuate down the stairs in any full-building evacuation unless explicitly instructed otherwise by on-site incident commanders, and that elevators can be used if they are still in service and haven’t been recalled or stopped.

d. Improved codes, laws, and regulations that do not restrict or impede building occupants during evacuation drills from familiarizing themselves with the detailed layout of alternative egress routes for a full building evacuation.*

[ * F-37 New York City Local Law 5 prohibits requiring occupants to practice stairwell evacuation during drills.]

Affected Standard: ICC/ANSI A117-1. Model Building and Fire Codes: The standard should be adopted in model building and fire codes by mandatory reference to, or incorporation of, the latest edition of the standard. Affected Organizations: NFPA, NIBS, NCSBCS, BOMA, and CTBUH.

NIST WTC Recommendation 17.

NIST recommends that tall buildings be designed to accommodate timely full building evacuation of occupants when required in building-specific or large-scale emergencies such as widespread power outages, major earthquakes, tornadoes, hurricanes without sufficient advance warning, fires, explosions, and terrorist attack. Building size, population, function, and iconic status should be taken into account in designing the egress system. Stairwell capacity and stair discharge door opening width* should be adequate to accommodate contraflow due to emergency access by responders.

[ * F-38 Egress capacity should be based on an all-hazards approach that considers the number and width of stairs (and door openings) as well as the possible use of scissor stairs credited as a single stair.]

a. Improved egress analysis models, design methodology, and supporting data should be developed to achieve a target evacuation performance (e.g. time for full building evacuation*) for the design building population by considering the building and egress system designs, and human factors such as occupant size, mobility status, stairwell tenability conditions, visibility, and congestion.

[ * F-39 Use of egress models is required to estimate the egress capacity for a range of different evacuation strategies, including full building evacuation. NIST found that the average surviving occupant in the WTC towers descended stairwells at about half the slowest speed previously measured for non-emergency evacuations.]

b. To the degree possible, mobility impaired occupants should be provided a means for self-evacuation in the event of a building emergency. Current strategies (and law) generally require the mobility impaired to shelter in place. New procedures, which provide redundancy in the event that the floor warden system or co-worker assistance (i.e. a buddy system) fails, should consider full building evacuation, and may include use of fire-protected and structurally hardened elevators,* motorized evacuation technology (e.g. a battery-operated evacuation chair), and/or dedicated communication technologies for the mobility impaired.

[ * F-40 Elevators should be explicitly designed to provide protection against large, but conventional, building fires. Fire-protected elevators also should be structurally hardened to withstand the range of foreseeable building-specific or large-scale emergencies. While progress has been made in developing the requirements and technologies for fire-protected elevators, similar criteria and designs for structurally hardened elevators remain to be developed.]

c. If protected/hardened elevators are provided for emergency responders but become unusable during an emergency, due to a malfunction or a conventional threat whose magnitude exceeds the magnitude considered in design, sufficient stairwell capacity should be provided to ensure timely emergency responder access to buildings that are undergoing full evacuation. Such capacity could be provided either via dedicated stairways for fire service use or by building sufficient stairway capacity (i.e. number and width of stairways and/or use of scissor stairs credited as a single stair) to accommodate the evacuation of building occupants while allowing access to emergency responders with minimal hindrance from occupant contraflow.

d. The egress allowance in assembly use spaces should be limited in state and local laws and regulations to no more than a doubling of the stairway capacity for the provision of a horizontal exit on a floor, as is the case now in the national model codes.* The use of a horizontal exit creates an area of refuge with a 2 hour fire rated separation, at least one stair on each side, and sufficient space for the expected occupant load.

[ * F-41 The New York City Building Code permits a doubling of allowed stair capacity when one area of refuge is provided on a floor, and a tripling of stair capacity for two or more areas of refuge on a floor. In the world after 11 September 2001, it is difficult to predict: (1) if, and for how long, occupants will be willing to wait in a refuge area before entering an egress stairway; and (2) what the impact would be of such a large group of people moving down the stairs on the orderly evacuation of lower floors.]

Affected Standards: NFPA 101, ASME A 17. Model Building and Fire Codes: The standards should be adopted in model building and fire codes by mandatory reference to, or incorporation of, the latest edition of the standard.

NIST WTC Recommendation 18.

NIST recommends that egress systems be designed: (1) to maximize remoteness of egress components (i.e. stairs, elevators, exits) without negatively impacting on average travel distances; (2) to maintain their functional integrity and survivability under foreseeable building-specific or large-scale emergencies; and (3) with consistent layouts, standard signage, and guidance so that systems become intuitive and obvious to building occupants during evacuations.

a. Within a safety-based design hierarchy that should be developed, highest priority should be assigned to maintain the functional integrity, survivability, and remoteness of egress components and active fire protection systems (sprinklers, standpipes, associated water supply, fire alarms, and smoke management systems). The design hierarchy should consider the many systems (e.g. stairs, elevators, active fire protection, mechanical, electrical, plumbing, and structural) and system components, as well as functional integrity, tenant access, emergency responder access, building configuration, security, and structural design.

b. The design, functional integrity, and survivability of the egress and other life safety systems (e.g. stairwell and elevator shafts, and active fire protection systems) should be enhanced by considering accidental structural loads such as those induced by overpressures (e.g. gas explosions), impacts, or major hurricanes and earthquakes, in addition to fire separation requirements. In selected buildings, structural loads due to other risks such as those due to terrorism may need to be considered. While NIST does not believe that buildings should be designed for aircraft impact, as the last line of defence for life safety, the stairwells and elevator shafts individually, or the core if these egress components are contained within the core, should have adequate structural integrity to withstand accidental structural loads and anticipated risks.

c. Stairwell remoteness requirements should be met by a physical separation of the stairwells that provide a barrier to both fire and accidental structural loads. Maximizing stairwell remoteness, without negatively impacting on average travel distances, would allow a stairwell to maintain its structural integrity independent of any other stairwell that is subject to accidental loads, even if the stairwells are located within the same structural barrier such as the core. The current ‘walking path’ measurement allows stairwells to be physically next to each other, separated only by a fire barrier. Reducing the clustering of stairways that also contain standpipe water systems provides the fire service with increased options for formulating firefighting strategies. This should not preclude the use of scissor stairs* as a means of increasing stair capacity – provided the scissor stair is only credited as a single stair.

[ * F-42 Two separate stairways within the same enclosure and separated by a fire rated partition.]

d. Egress systems should have consistent layouts with standard signage and guidance so that the systems become intuitive and obvious to all building occupants, including visitors, during evacuations. Particular consideration should be given to unexpected deviations in the stairwells (e.g. floors with transfer hallways).

Affected Standard: NFPA 101. Model Building and Fire Codes: The standard should be adopted in model building and fire codes by mandatory reference to, or incorporation of, the latest edition of the standard.

NIST WTC Recommendation 19.

NIST recommends that building owners, managers, and emergency responders develop a joint plan and take steps to ensure that accurate emergency information is communicated in a timely manner to enhance the situational awareness of building occupants and emergency responders affected by an event. This should be accomplished through better co-ordination of information among different emergency responder groups, efficient sharing of that information among building occupants and emergency responders, more robust design of emergency public address systems, improved emergency responder communication systems, and use of the Emergency Broadcast System (now known as the Integrated Public Alert and Warning System) and Community Emergency Alert Networks.

a. Situational awareness of building occupants and emergency responders in the form of information and event knowledge should be improved through better co-ordination of such information among emergency responder groups (9-1-1 dispatch, fire department or police department dispatch, emergency management dispatch, site security, and appropriate federal agencies), efficient sharing and communication of information between building occupants and emergency responders, and improved emergency responder communication systems (i.e. including effective communication within steel and reinforced concrete buildings, capacity commensurate with the scale of operations, and interoperability among different communication systems.

b. The emergency communications systems in buildings should be designed with sufficient robustness and redundancy to continue providing public address announcements or instructions in foreseeable building-specific or large-scale emergencies, including widespread power outage, major earthquakes, tornadoes, hurricanes, fires, and accidental explosions. Consideration should be given to placement of building announcement speakers in stairways in addition to other standard locations.

c. The Integrated Public Alert and Warning System (IPAWS) should be activated and used, especially during large-scale emergencies, as a means to rapidly and widely communicate information to building occupants and emergency responders to enhance their situational awareness and assist with evacuation.

d. Local jurisdictions (cities and counties or boroughs) should seriously consider establishing a Community Emergency Alert Network (CEAN), within the framework of IPAWS, and make it available to the citizens and emergency responders of their jurisdictions to enhance situational awareness in emergencies.* The network should deliver important emergency alerts, information and real time updates to all electronic communication systems or devices registered with the CEAN. These devices may include e-mail accounts, cell/mobile phones, text pagers, satellite phones, and wireless PDA’s.

[ * F-43 Types of emergency communications could include life safety information, severe weather warnings, disaster notifications (including information on terrorist attacks), directions for self-protection, locations of nearest available shelters, precautionary evacuation information, identification of available evacuation routes, and accidents or obstructions associated with roadways and utilities.]

Affected Standard: NFPA 101, and/or a new standard. Model Building and Fire Codes: The standard should be adopted in model building and fire codes by mandatory reference to, or incorporation of, the latest edition of the standard to the extent it is within the scope of building and fire codes.

NIST WTC Recommendation 20.

NIST recommends that the full range of current and next generation evacuation technologies should be evaluated for future use, including protected/hardened elevators, exterior escape devices, and stairwell descent devices, which may allow all occupants an equal opportunity for evacuation and facilitate emergency response access. Affected Standards: NFPA 101, ASME A 17, ASTM E 06, ANSI A117.1. Model Building and Fire Codes: The standards should be adopted in model building and fire codes by mandatory reference to, or incorporation of, the latest edition of the standard.

END

Accessible Toilet Room in a Japanese Public Place – Kanazawa

CJ Walsh — Mon, 28 Nov 2011 13:08:08 +0000

2011-11-28: Further to my post, dated 20 October 2010 …

A valuable and essential facility in the grounds of Kanazawa Castle, Japan … entered directly from the exterior … is this Accessible Toilet Room / WC / Bathroom / Hygiene Room / Rest Room / Sanitary Room (whichever term you are familiar with) provided for public use. There is no attendant permanently present, and no camera surveillance of the external entrance area. However, it is regularly cleaned and properly maintained during the Castle’s opening hours.

Colour photograph showing Kanazawa Castle and its grounds, in Japan. Photograph by CJ Walsh. 2010-04-27. Click to enlarge.

The following photographs show a far more ‘developed’, ‘civilized’ and ‘person-centred’ approach to the design and fit-out of these public facilities (quite common in Japan) … than here in Europe.

Real Accessibility-for-All in action … with no messing around …

Colour photograph showing a Public Toilet Room in the grounds of Kanazawa Castle, Japan ... which is Accessible-for-All. Photograph by CJ Walsh. 2010-04-27. Click to enlarge.

Colour photograph showing a Public Toilet Room in the grounds of Kanazawa Castle, Japan ... which is Accessible-for-All. Detailed view of toilet controls and accessories. Photograph by CJ Walsh. 2010-04-27. Click to enlarge.

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NIST WTC Recommendations 12-15 > Improved Active Protection

CJ Walsh — Fri, 25 Nov 2011 16:52:35 +0000

Previous Posts in This Series …

2011-10-25: NIST’s Recommendations on the 9-11 WTC Building Collapses … GROUP 1. Increased Structural Integrity – Recommendations 1, 2 & 3 (out of 30)

2011-11-18: NIST WTC Recommendations 4-7 > Structural Fire Endurance … GROUP 2. Enhanced Fire Endurance of Structures – Recommendations 4, 5, 6 & 7

2011-11-24: NIST WTC Recommendations 8-11 > New Design of Structures … GROUP 3. New Methods for Fire Resisting Design of Structures – Recommendations 8, 9, 10 & 11

2011-11-25: SOME PRELIMINARY COMMENTS …

1. Reliability has always been an issue with Active Fire Protection Systems … but, it is neither acknowledged, nor fully understood, that … Reliability Is Equally An Issue With Passive Fire Protection Measures !

Furthermore, the following should always be taken into account when considering the Safety Factors to be applied in calculating the level of satisfactory fire safety and protection which is provided in a specific project … one of the design objectives in Ethical Fire Engineering.

For example, if Category C below is indicative of the design and construction quality on a particular building site … just think of the Priory Hall Apartment Development in Dublin (!) … the Safety Factors to be applied in the design should be high … and with regard to actual construction, it should be expected that the Reliability of both Active Fire Protection Systems and Passive Fire Protection Measures will be initially low … with Life Cycle Reliability being entirely non-existent.

Quality of Fire Engineering Design & Related Construction

Category A

(a) Design of the works is exercised by an independent, appropriately qualified and experienced architect/engineer/fire engineer, with design competence relating to fire safety and protection in buildings ;

(b) Installation/fitting of related construction products/systems is exercised by appropriately qualified and experienced personnel, with construction competence relating to fire safety and protection in buildings ;

(c) Supervision of the works is exercised by appropriately qualified and experienced personnel from the principal construction organization ;

(d) Regular inspections, by appropriately qualified and experienced personnel familiar with the design, and independent of the construction organization(s), are carried out to verify that the works are being executed in accordance with the fire engineering design.

Category B

(a) Design of the works is exercised by an independent, appropriately qualified and experienced architect/engineer/fire engineer ;

(b) Installation/fitting of fire-related construction products/systems is exercised by appropriately qualified and experienced personnel ;

(c) Supervision of the works is exercised by appropriately qualified and experienced personnel from the principal construction organization.

Category C

This level of design and construction execution is assumed when the requirements for Category A or Category B are not met.

2. With regard to Recommendations 12 & 13 below … in an earlier post in this series, and elsewhere, I have defined Disproportionate Damage … and differentiated that structural concept from the related concept of Fire-Induced Progressive Collapse.

A significant number of countries include a requirement on Resistance to Disproportionate Damage in their national building codes. Often, it is only necessary to consider this requirement in the case of buildings having 5 Storeys, or more … a completely arbitrary height threshold. I would consider that adequately tying together the horizontal and vertical structural elements of a building … any building … is a fundamental principle of good structural engineering !!

Putting it simply … for the purpose of showing compliance with this structural requirement … it is necessary to demonstrate that a building will remain structurally stable if a portion of the building’s structure is removed … always remembering that every building comprises both structure and fabric, i.e. non-structure.

In reality this may happen, and quite often does happen, when, for example, a large truck runs into the side of a building, which can happen anywhere … or there is a gas explosion in some part of the building, which happened in Dublin’s Raglan House back in 1987, and many times in other countries … or a plane hits a high-rise building, which happened to Milan’s iconic Pirelli Tower in 2002, and to New York’s Empire State Building way back in 1945 … etc., etc. Raglan House collapsed … the Pirelli Tower and the Empire State Building did not.

[ The World Trade Center Towers were originally designed to absorb the impact of a large plane and to remain structurally stable afterwards ... in ambient conditions. However, what was not considered in the ambient structural design was 'fire', i.e. the fuel tanks were empty and no fire in the building would be initiated as a result of the mechanical damage caused by the plane impact ... which, on 11 September 2001, proved to be a ridiculous basis for any structural design ! This is why 9-11 should be regarded, at its core, as being a very serious 'real' fire incident.]

What I am leading up to is this … the concept of removing a portion of a building, and it remaining structurally stable afterwards … should now – logically and rationally – also be incorporated into the fire engineering design of Active Fire Protection Systems. In other words, if a portion of a building is removed, will any particular Active Fire Protection System continue to operate effectively in the rest of the building ? This has implications for the location and adequate protection of critical system components in a building … and for the necessary redundancy, zoning and back-up alternative routeing which must be designed into the system from the beginning !

2005 NIST WTC RECOMMENDATIONS

GROUP 4. Improved Active Fire Protection

NIST WTC Recommendation 12.

NIST recommends that the performance and possibly the redundancy of active fire protection systems (sprinklers, standpipes/hoses, fire alarms, and smoke management systems) in buildings be enhanced to accommodate the greater risks associated with increasing building height and population, increased use of open spaces, high-risk building activities, fire department response limits, transient fuel loads, and higher threat profile. The performance attributes should deal realistically with the system design basis, reliability of automatic/manual operations, redundancy, and reduction of vulnerabilities due to single point failures. Affected Standards: NFPA 13, NFPA 14, NFPA 20, NFPA 72, NFPA 90A, NFPA 92A, NFPA 92B, and NFPA 101. Model Building Codes: The performance standards should be adopted in model building codes by mandatory reference to, or incorporation of, the latest edition of the standard.

NIST WTC Recommendation 13.

NIST recommends that fire alarm and communications systems in buildings be developed to provide continuous, reliable, and accurate information on the status of life safety conditions at a level of detail sufficient to manage the evacuation process in building fire emergencies; all communication and control paths in buildings need to be designed and installed to have the same resistance to failure and increased survivability above that specified in present standards. This should include means to maintain communications with evacuating occupants that can both reassure them and redirect them if conditions change. Pre-installed fire warden telephone systems can serve a useful purpose and may be installed in buildings and, if so, they should be made available for use by emergency responders. All communication and control paths in buildings need to be designed and installed to have the same resistance to failure and increased survivability above that specified in present standards. Affected Standards: NFPA 1, NFPA 72, and NFPA 101. Model Building and Fire Codes: The performance standards should be adopted in model building and fire codes by mandatory reference to, or incorporation of, the latest edition of the standard.

NIST WTC Recommendation 14.

NIST recommends that control panels at fire/emergency command stations in buildings be adapted to accept and interpret a larger quantity of more reliable information from the active fire protection systems that provide tactical decision aids to fire ground commanders, including water flow rates from pressure and flow measurement devices, and that standards for their performance be developed. Affected Standards: NFPA 1, NFPA 72, and NFPA 101. Model Building and Fire Codes: The performance standards should be adopted in model building and fire codes by mandatory reference to, or incorporation of, the latest edition of the standard.

NIST WTC Recommendation 15.

NIST recommends that systems be developed and implemented for: (1) real time off-site secure transmission of valuable information from fire alarm and other monitored building systems for use by emergency responders, at any location, to enhance situational awareness and response decisions, and maintain safe and efficient operation;* and (2) preservation of that information either off-site, or in a black box that will survive a fire or other building failure, for purposes of subsequent investigations and analysis. Standards for the performance of such systems should be developed, and their use should be required. Affected Standards: NFPA 1, NFPA 72, and NFPA 101. Model Building and Fire Codes: The performance standards should be adopted in model building and fire codes by mandatory reference to, or incorporation of, the latest edition of the standard.

[ * F-35 The alarm systems in the WTC towers were only capable of determining and displaying: (a) areas that had at some time reached alarm point conditions; and (b) areas that had not. The quality and reliability of information available to emergency responders at the Fire Command Station was not sufficient to understand the fire conditions. The only information transmitted outside the buildings was the fact that the buildings had gone into alarm. Further, the fire alarm system in WTC Building 7, which was transmitted to a monitoring service, was on 'test mode' during the morning of 11 September 2001, because routine maintenance was being performed. Under test mode conditions: (1) the system is typically disabled for the entire building, not just for the area where work is being performed; and (2) alarm signals typically do not show up on an operator console.]

END

‘Greening’ Ireland’s Economy – Will Somebody Please Get Real ?

CJ Walsh — Mon, 21 Nov 2011 16:58:20 +0000

2011-11-21: The International Labour Office (ILO), in Geneva, and the European Union’s Centre for the Development of Vocational Training (CEDEFOP) … have recently published a Joint Report: ‘Skills for Green Jobs – A Global View’ …

ILO – EU CEDEFOP

‘Skills for Green Jobs – A Global View’ (a synthesis report based on 21 country reports)

Click the Link Above to read and/or download PDF File (5.3 Mb)

The vision is positive … its advice is practical … and the writers actually sound as if they know what they are talking about. And it is evident that the word ‘green’ is used, in this Report, as a simple means of communicating the far more complex concept of ‘sustainable human and social development’, with all of its many different aspects. Judge for yourself by reading the extract from the Executive Summary below.

This Report’s contents also complement, very neatly, what has been said here in many posts … concerning the institutional infrastructure necessary, in societies, to properly implement an effective response to policies of energy conservation and security, climate change and sustainable development.

WAYS FORWARD [ Pages xxiv to xxvi, Executive Summary, ILO - EU CEDEFOP Report: 'Skills for Green Jobs - A Global View' ]

It is important to remember that skills are not a poor servant of the economy, expected merely to react and adjust to any change. The availability of a suitably trained workforce capable of further learning inspires confidence that in turn encourages investment, technical innovation, economic diversification and job creation.

Policies Need to be Informed, Coherent and Co-Ordinated

When policies to green the economy and policies to develop skills are not well connected, skill bottlenecks will slow the green transformation, and potential new jobs will be lost. Strategic, leadership and management skills that enable policy-makers in governments, employers’ associations and trade unions to set the right incentives and create enabling conditions for cleaner production and services are an absolute priority.

Environmental awareness as an integral part of education and training at all levels, introduced as a core skill from early childhood education onwards, will eventually push consumer behaviour and preferences and the market itself.

Labour market information for anticipating and monitoring skill needs for green jobs is the critical starting point for effective policy cycles. This enables governments and businesses to anticipate changes in the labour market, identify the impact on skill requirements, incorporate changes into the system by revising training programmes and introducing new ones, and monitor the impact of training on the labour market.

The country studies that told the most successful stories prove the value of effective co-ordination among line ministries and social partners, achieved by creating task forces for human resource development for a greening economy, or by incorporating training and skills issues into a council for environmental development. It is important that the platform for this dialogue has decision-making authority, can establish clear commitments among all those partners involved and allocate human and financial resources to them, and has agreed responsibilities not only for planning but for implementation. A win–win situation can only be achieved if environment, jobs and skills are discussed, planned and implemented in conjunction with each other.

Decentralized approaches can actually promote policy co-ordination and coherence at sectoral and local levels. Direct dialogue between national and regional governments and social partners can be translated into action when commitments and resource allocation occur at a smaller scale and where immediate dividends are obvious for all partners involved. A good combination of top-down co-ordinated policy-making with bottom-up sectoral or local initiatives can support effective training-intensive green transitions.

Policies Need to be Targeted

The transformation to greener economies provides an opportunity to reduce social inequalities. Social justice dictates that training initiatives target those who lose jobs during the transition, especially those who are typically at a disadvantage in the labour market and may require special assistance. The growth dividend from greening the economy will be attained only if access to new training provided as part of green measures is made accessible to disadvantaged youth, persons with disabilities, rural communities and other vulnerable groups. Incentives to increase women’s participation in technical training programmes will not only increase their participation in technology-driven occupations but also help solve the skill shortage problem in this segment of the labour market.

Green Transitions Affect the Entire Training System

Taking into account all three types of skills change – that resulting from employment shifts within and across sectors as the consequence of green restructuring, that associated with new and emerging occupations, and the massive change in the content of established occupations – it becomes clear that the whole training system must be mobilized. Adjusting training programmes to green changes in the labour market is a transversal task across levels and types of education and training.

So far, compulsory level and tertiary education have been catching up rather well, whereas technical and vocational education and training has been lagging behind in adapting to the needs of the green economy. Improving adjustment here can give new impetus to employment-centred and fair green transitions and requires the following key challenges to be met:

Putting basic skills high on the policy agenda, as a foundation of flexibility and employability throughout the life cycle ;
Matching classroom and practical training through apprenticeships, internships, job placements, projects on the job etc ;
Adjusting the length and breadth of training provision according to different types of skills change ;
Equipping teachers and trainers with up-to-date knowledge on environmental issues and on green technologies – education and training which deals with preparation of teachers and trainers should be one of the first priorities in skills response strategies ;
Enabling active labour market policy measures (ALMP’s) to take into account green structural change and to provide access to relevant training and other employment activation measures ; and
Deploying public employment services (PES), as important players in job matching and training, to raise awareness about green business opportunities and related skill needs.

The linchpin of effective skills development for greening the economy is co-ordination. The degree of co ordination between public and private stakeholders and the degree of involvement of social partners are decisive. Concerted measures need to be undertaken by governments at different levels, including the community level, employers and workers, through institutional mechanisms of social dialogue, such as national or regional tripartite councils, sector or industry skills councils, public–private partnerships and the like.

Developing Countries Need Special Measures

Developing countries, and the workers and employers in them, have the least responsibility for climate change and environmental degradation but suffer their economic and social consequences disproportionately. Special measures that can speed their employment-centred green transformations include:

- capacity building for employers in the informal economy and micro- and small enterprises to enter green markets in localities where they are most needed ;

- entrepreneurship training and business coaching for young people and adults to start up green businesses in conjunction with micro-finance projects ;

- environmental awareness among decision-makers, business leaders and administrators as well as institutions of formal and non-formal training systems ;

- capacity building of tripartite constituents to strengthen social dialogue mechanisms and to apply these to dialogue about accessibility of training for green jobs ; and

- increased capacity of formal education and training systems and institutions to provide basic skills for all and to raise the skills base of the national workforce ; this includes improving apprenticeship systems and building synergies with NGO’s that provide education and training.

These measures can only be taken if resources are available. It is therefore recommended that not only national governments but also international partnerships in developing countries take these recommendations into account both in environment programmes and in skills development programmes.

‘GREENING’ IRELAND’s ECONOMY ?

Ireland was not one of the countries examined in the ILO / EU CEDEFOP Project. That should tell us a lot !

BUT … just pause for a moment … and meditate on the many skill-related issues arising from the debacle at the Priory Hall Apartment Development, in Dublin.

AND NOW … read the following extracts from recent Irish National Reports … ‘high notions’ from goats in the Kerry Mountains …

The Overarching Vision – Forfás Report: ‘Future Skills Needs of Enterprise within the Green Economy in Ireland’ (November 2010) …

” For Ireland to be the benchmark ‘smart green’ economy for population centres under 20 million by 2015 – and to have the skills base and talent to drive innovative and high value products and services and maximise future business and employment growth potential.”

Final Paragraphs, #7 Conclusions – Review of National Climate Policy (November 2011) …

” In the wider-international context, there are also encouraging signs of a new ‘green growth’ paradigm which emphasises resource efficiency, the protection of natural resources and competitiveness along with the creation of new jobs. A long-term view of how Ireland aligns its economic development with the demands of the growth engines of global commerce should be at the core of a low-carbon development vision. In order to create enabling conditions for selling into these markets, many of which are already gearing up for the green economy, it will be necessary to ensure that the domestic conditions are right to encourage innovation. This can be done by showing environmental ambition and using tools that allow the market to identify solutions. That will require a combination of taking the best of what is working in other countries as well as devising domestically appropriate policies that will place Ireland in the vanguard of countries making the most of the opportunities presented by the green economy.

In terms of a long-term national vision of a carbon-constrained world, Ireland is faced with both the challenge of addressing a unique greenhouse gas emissions profile and the opportunity to position itself as an enlightened society with an environmentally sustainable and competitive, low-carbon economy. Developing the policies to put Ireland on a clear and definite path to achieve that vision is the immediate priority.”

Who Are These Moráns ?!? Will Somebody Please Get Real !?!

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