Approved Document B (England & Wales)

NIST WTC Recommendations 8-11 > New Design of Structures

Previous Posts in This Series …

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

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

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2011-11-24:  SOME PRELIMINARY COMMENTS …

  1.     The first of two NIST Publications being referenced in this Series of Posts is as follows …

NIST (National Institute of Standards and Technology).  September 2005.  Federal Building and Fire Safety Investigation of the World Trade Center Disaster: Final Report on the Collapse of the World Trade Center Towers.  NIST NCSTAR 1.  Gaithersburg, MD, USA.

The 2005 NIST Report concludes, in Chapter 9, with a list of 30 Recommendations for Action, grouped together under the following 8 Subject Headings

i)        Increased structural integrity ;

ii)       Enhanced fire endurance of structures ;

iii)      New methods for fire resisting design of structures ;

iv)      Enhanced active fire protection ;

v)       Improved building evacuation ;

vi)      Improved emergency response ;

vii)     Improved procedures and practices ;   and

viii)    Education and training.

NIST has clearly stated that “the numerical ordering (of the Recommendations) does not reflect any priority”.

From my point of view, the 2005 NIST Report is especially noteworthy for the emphasis placed on:

(a)     The 3 R’s … Reality – Reliability – Redundancy ;

(b)     Evacuation Way Finding … should be ‘intuitive and obvious’ … a major challenge for building designers, since buildings are still typically designed for ‘access’ only.  In order to find the evacuation routes in a building, it is usually necessary to have a compass, a map, a magnifying glass, a torch … and a prayer book !!!   More about this in later posts …

  2.     However, following on from NIST’s emphasis on Reality … and just between you, me and the World Wide Web … there is a lot of misunderstanding in the International Fire Science and Engineering Community about what exactly is the Realistic End Condition.  But, here it goes …

Realistic End Condition:  A ‘real’ fire in a ‘real’ building, which is used by ‘real’ people with varying abilities in relation to self-protection, independent evacuation to a ‘place of safety’, and participation in the Fire Defence Plan for the building.

It is strange, therefore … and quite unacceptable … to have to point out that the Realistic End Condition IS NOT … a test fire or an experimental fire in a laboratory … or a design fire in a computer model, even IF it is properly validated !

  3.     With regard to Recommendation 8 below … NIST’s contention that “Current methods for determining the fire resistance of structural assemblies do not explicitly specify a performance objective” is not strictly the case.

If we examine Technical Guidance Document B (Ireland) and Approved Document B (England & Wales) once again, as examples close to home … Part B: ‘Fire Safety’ in both jurisdictions should be read in conjunction with its associated Part A: ‘Structure’, which contains a requirement on Disproportionate Damage.

In everyday practice, however, this never happens.  Instead, people dealing with Part B in both jurisdictions enter a sort of bubble … a twilight zone … and, if there is anything to do with structural performance in fire, they immediately refer to the Appendices at the back of both Guidance Documents (ignoring Part A altogether) … where we find a ‘single element’ approach to design, no consideration of connections, etc., etc., etc.

And … this fundamental error is further reinforced in Ireland because, under the national system of Fire Safety Certification for buildings, it is only Part B which is relevant.

At European Level, I would make the same point … under EU Regulation 305/2011 on Construction Products … Basic Requirement for Construction Works 2: ‘Safety in Case of Fire’ must be read in conjunction with Basic Requirement 1: ‘Mechanical Resistance & Stability’ … where we will again find a direct reference to Disproportionate Damage … and an indirect, but explicit, reference to Serviceability Limit States under normal conditions of use … including fire !

A major gap … the missing link at international level … is the failure, still, to elaborate and flesh out the structural concept of Fire-Induced Progressive Collapse.  More about this in later posts …

  4.     With regard to Recommendation 10 below … and amplifying my earlier comments concerning Recommendation 6 … the manufacturers of all Lightweight Structural Fire Protection Systems … not just the Sprayed Systems … have a lot to answer for.

Major question marks concerning Life Cycle Durability, and Resistance to Mechanical Damage at any stage in a building’s life cycle, hang over all of these systems.

Fire testing, alone, does not show that a Lightweight Structural Fire Protection System is ‘fit for its intended use’ !   And manufacturers well know this !!!

And as for the Installation of Lightweight Structural Fire Protection Systems on site … it’s a hornets’ nest that nobody wants to touch !

Vested interests … vested interests … vested interests !!!

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2005 NIST WTC RECOMMENDATIONS

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 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.

NIST WTC 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.

This performance-based capability should include the development of, but not be limited to:

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.

Affected National and International Standards:  ASCE-7, AISC Specifications, ACI 318, and ASCE/SFPE 29 for fire resistance design and retrofit of structures;  NFPA, SFPE, ASCE, and ISO TC92 SC4 for building-specific multi-compartment, multi-floor design basis fire scenarios;  and ASTM, NFPA, UL, and ISO for new test methods.  Model Building Codes:  The performance standards should be adopted as an alternative method in model building codes by mandatory reference to, or incorporation of, the latest edition of the standard.

NIST WTC Recommendation 10.

NIST recommends the development and evaluation of new fire resisting coating materials, systems, and technologies with significantly enhanced performance and durability to provide protection following major events.  This could include, for example, technologies with improved adhesion, double-layered materials, intumescent coatings, and more energy absorbing SFRM’s.*  Consideration should be given to pre-treatment of structural steel members with some type of mill-applied fire protection to minimize the uncertainties associated with field application and in-use damage.  If such an approach were feasible, only connections and any fire protection damaged during construction and fit-out would need to be field-treated.  Affected Standards:  Technical barriers, if any, to the introduction of new structural fire resisting materials, systems and technologies should be identified and eliminated in the AIA MasterSpec, AWCI Standard 12 and ASTM standards for field inspection, conformance criteria, and test methods.  Model Building Codes:  Technical barriers, if any, to the introduction of new structural fire resisting materials, systems, and technologies should be eliminated from the model building codes.

[ * F-34  Other possibilities include encapsulation of SFRM by highly elastic energy absorbing membranes or commodity grade carbon fibre or other wraps.  The membrane would remain intact under shock, vibration, and impact but may be compromised in a fire, yet allowing the SFRM to perform its thermal insulation function.  The carbon wrap would remain intact under shock, vibration, and impact, and possibly under fire conditions as well.]

NIST WTC Recommendation 11.

NIST recommends that the performance and suitability of advanced structural steels, reinforced and pre-stressed concrete, and other high-performance material systems be evaluated for use under conditions expected in building fires.  This evaluation should consider both presently available and new types of steels, concrete, and high-performance materials to establish the properties (e.g. yield and ultimate strength, modulus, creep behaviour, and failure) that are important for fire resistance, establish needed test protocols and acceptance criteria for such materials and systems, compare the performance of newer systems to conventional systems, and the cost-effectiveness of alternative approaches.  Technical and standards barriers to the introduction and use of such advanced steels, concrete, and other high-performance material systems should be identified and eliminated, or at least minimized, if they are found to exist.  Affected Standards:  AISC Specifications and ACI 318.  Technical barriers, if any, to the introduction of these advanced systems should be eliminated in ASTM E 119, NFPA 251, UL 263, ISO 834.  Model Building Codes:  Technical barriers, if any, to the introduction of these advanced systems should be eliminated from the model building codes.

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NIST WTC Recommendations 4-7 > Structural Fire Endurance

First Post 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)

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2011-11-18:  SOME PRELIMINARY COMMENTS …

  1.     Before launching into the next Group of NIST WTC Recommendations, it would be useful to distinguish between the following technical terms … which have been adapted from ISO/TR 10158: ‘Principles and Rationale Underlying Calculation Methods in Relation to Fire Resistance of Structural Elements’

Real Fire:  A fire which develops in a building and which is influenced by such factors as the type of building and its occupancy;  the combustible content (fire load);  the ventilation, geometry and thermal properties of the fire compartment, or building space (should no fire compartmentation exist);  the fire suppression systems in the building and the actions of the fire services.

Real Fires are complex phenomena.  Consequently, in structural fire engineering, idealized versions of ‘real fires’ are employed.

Experimental Fire:  A full or reduced scale fire with specified and controlled characteristics.

Design Fire:  A fire with specified exposure data intended for use in connection with structural fire engineering calculations.

A Design Fire may either be representative of the thermal exposure described by the standard time-temperature-pressure relationship in an International/European/National Standard, or some non-standard exposure intended to simulate particular fire exposure conditions.

However, in SDI Technical Guidance Note 95/102: ‘Proper Evidence of a Fire Test Result within the European Economic Area (EEA)’, issued on 22 May 1995, I included the following caution …

#1.7  A Fire Test in a Fire Test Laboratory, involving exposure of a test specimen or prototype to ‘test fire’ conditions, gives only a limited indication of:  (a) the likely performance of a particular product, material or component when exposed to ‘real fire’ conditions;  and (b) the suitability of a product, material or component for a particular end use.

  2.     In conventional fire engineering, much confusion arises because of a failure to properly distinguish between these two concepts …

Fire Resistance

The inherent capability of a building assembly, or an ‘element of construction’, to resist the passage of heat, smoke and flame for a specified time during a fire.

Structural Reliability

The ability of a structural system to fulfil its design purpose, for a specified time, under the actual environmental conditions encountered in a building.

[ In structural fire engineering, the concern must be that the structure will fulfil its purpose, both during the fire – and for a minimum period afterwards, during the ‘cooling phase’.]

  3.     Therefore, with regard to Recommendation 6 … it is more correct and precise to refer to ‘Steel Fire Protection Systems’, rather than to ‘steel fire resisting materials’ !   AND … the same questions must be asked about All Lightweight Steel Fire Protection Systems … not just the sprayed systems.

Lightweight Fire Protection Systems are also used to protect concrete in buildings and tunnels.

  4.     These 2005 NIST Recommendations will later be confirmed, and further reinforced, by the 2008 NIST Recommendations.  Bringing Recommendation 7, below, closer to home … it is interesting to note that a very necessary discussion on the technical adequacy of the approach taken to structural performance in fire … in both Technical Guidance Document B (Ireland) and Approved Document B (England & Wales) … has yet not even commenced !

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2005 NIST WTC RECOMMENDATIONS

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 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-23  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.  It is not clear how the current height and areas tables in building codes consider 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-24  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-25  The passive fire protection system (including 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-26  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-27  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.

Adoption of this Recommendation will allow building codes to distinguish the risks associated with different building heights, fuel concentrations, and fire protection systems.  Research is needed to develop the data and evaluate alternative proposals for construction classifications and fire ratings.  Model Building Codes:  A comprehensive review of current construction classifications and fire rating requirements and the establishment of a uniform set of revised thresholds with a firm technical basis that considers the factors identified above should be undertaken.*

[ * F-28  The National Fire Protection Association (NFPA) 5000 model code and the International Building Code (IBC) both recognize the risks associated with different building heights and accepted changes in 2001 and 2004, respectively.  Both model codes now require that buildings 126 metres and higher have a minimum 4 hour structural fire resistance rating.  The previous requirement was 2 hours.  The change provides increased fire resistance for the structural system leading to enhanced tenability of the structure and gives firefighters additional protection while fighting a fire.  While NIST supports these changes as an interim step, NIST believes that it is essential to complete a comprehensive review that will establish a firm technical basis for construction classifications and fire rating requirements.]

NIST WTC 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.

This effort should address the technical issues listed below: *

[ * F-29  The technical issues were identified from the series of four fire resistance tests of the WTC Floor system, and the review and analysis of relevant documents that were conducted as part of this Investigation.]

a.     Criteria and test methods for determining:

  • structural limit states, including failure, and means for measurement ;
  • effect of scale of test assembly versus prototype application, especially for long-span structures that significantly exceed the size of test furnaces ;
  • effect of restraining thermal expansion (end-restraint conditions) on test results, especially for long-span structures that have greater flexibility ;
  • fire resistance of structural connections, especially the fire protection required for a loaded connection to achieve a specified rating ; *

[ * F-30  There is a lack of test data on the fire resistance ratings of loaded connections.  The fire resistance of structural connections is not rated in current practice.  Also, standards and codes do not provide guidance on fire protection requirements for structural connections when the connected members have different fire resistance ratings.]

  • effect of the combination of loading and exposure (time-temperature profile) required to adequately represent expected conditions ;
  • the repeatability and reproducibility of test results (typically, results from a single test are used to determine the rating for a component or assembly) ;   and
  • realistic ratings for structural assemblies made with materials that have improved elevated temperature properties (strength, modulus, creep behaviour).

b.     Improved procedures and guidance to analyze and evaluate existing data from fire resistance tests of building components and assemblies for use in qualifying an untested building element.

c.     Relationships between prescriptive ratings and performance of the assembly in real fires.

Affected National and International Standards: * ASTM E 119, NFPA 251, UL 263, and ISO 834.  Model Building Codes:  The standards should be adopted in model building codes by mandatory reference to, or incorporation of, the latest edition of the standard.

[ * F-31  While the NIST Recommendations are focused mainly on U.S. national standards, each U.S. standard has counterpart international standards.  In a recent report (ISO/TMB AGS N 46), the International Organization for Standardization (ISO), through its Advisory Group for Security (AGS), has recommended that since many of the ISO standards for the design of buildings date back to the 1980’s, they should be reviewed and updated to make use of the studies done by NIST on the World Trade Center disaster, the applicability of new technology for rescue from high buildings, natural disasters, etc.  ISO’s Technical Advisory Group 8 co-ordinates standards work for buildings.]

NIST WTC Recommendation 6.

NIST recommends the development of criteria, test methods, and standards:  (1) for the in-service performance of Sprayed Fire Resisting Materials (SFRM, also commonly referred to as fire protection insulation) used to protect structural components;  and (2) to ensure that these materials, as installed, conform to conditions in tests used to establish the fire resistance rating of components, assemblies, and systems.

This should include:

  • Improved criteria and testing methodologies for the performance and durability of SFRM (e.g. adhesion, cohesion, abrasion, and impact resistance) under in-service exposure conditions (e.g. temperature, humidity, vibration, impact, with/without primer paint on steel*) for use in acceptance and quality control.  The current test method to measure the bond strength, for example, does not distinguish the cohesive strength from the tensile and shear adhesive strengths.  Nor does it consider the effect of primer paint on the steel surface.  Test requirements that explicitly consider the effects of abrasion, vibration, shock, and impact under normal service conditions are limited or do not exist.  Also, the effects of elevated temperatures on thermal properties and bond strength are not considered in evaluating the performance and durability of SFRM.

[ * F-32  NIST tests show that the adhesive strength of SFRM on steel coated with primer paint was a third to half of the adhesive strength on steel that had not been coated with primer paint.  The SFRM products used in the WTC towers were applied to steel components coated with primer paint.]

  • Inspection procedures, including measurement techniques and practical conformance criteria, for SFRM in both the building codes and fire codes for use after installation, renovation, or modification of all mechanical and electrical systems and by fire inspectors over the life of the building.  Existing standards of practice (AIA MasterSpec and AWCI Standard 12), often required by codes for some buildings need to be broadly applied to both new and existing buildings.  These standards may require improvements to address the issues identified in this Recommendation.
  • Criteria for determining the effective uniform SFRM thickness – thermally equivalent to the variable thickness of the product as it is actually applied – that can be used to ensure that the product in the field conforms to the near uniform thickness conditions in the tests used to establish the fire resistance rating of the component, assembly, or system.  Such criteria are needed to ensure that the SFRM, as installed, will provide the intended performance.
  • Methods for predicting the effectiveness of SFRM insulation as a function of its properties, the application characteristics, and the duration and intensity of the fire.
  • Methods for predicting service life performance of SFRM under in-service conditions.

Affected Standards:  AIA MasterSpec and AWCI Standard 12 for field inspection and conformance criteria; ASTM standards for SFRM performance criteria and test methods.  Model Building Codes:  The standards should be adopted in model building codes by mandatory reference to, or incorporation of, the latest edition of the standard.  (See Recommendation 10 for more on this issue.)

NIST WTC Recommendation 7.

NIST recommends the adoption and use of the ‘structural frame’ approach to fire resistance ratings.  This approach requires that structural members – such as girders, beams, trusses, and spandrels having direct connection to the columns, and bracing members designed to carry gravity loads – be fire protected to the same fire resistance rating as columns.  This approach is currently required by the International Building Code (IBC), one of the model codes, and is in the process of adoption by NFPA 5000, the other model code.  This requirement 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.

[ * F-33  Had this requirement been adopted by the 1968 New York City building code, the WTC floor system, including its connections, would have had the 3 hour rating required for the columns since the floors braced the columns.]

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Fire Evacuation of People with Disabilities – Reality Bites ?

2009-03-10:   Regarding Seán’s Comment, dated 2009-03-06.

 

Yes, the guidance provided in Technical Guidance Document B (Ireland) is inadequate … and the same can equally be said of Approved Document B (England & Wales).

 

And yes, you will find only partial answers in British Standard BS 9999, even though it was only published on 31st October 2008 last.

 

Access Consultants in Ireland and Great Britain rarely deal with any matters relating to fire safety in buildings.

 

 

 

Please allow me, therefore, to fill in some gaps for you.  The following guidance is suitable for application in any European country …

 

People with Activity Limitations (2001 WHO ICF) experience many difficulties when attempting to independently evacuate a fire building.  However, our reasoning is very simple.  If we can get things right for the most vulnerable building users, we get them right for everyone else also.

 

 

The Target Destination … whether evacuation is independent, assisted by other building users or accomplished by means of firefighter rescue … is a ‘Place of Safety’.  This term is not well defined in legislation or codes.

 

Building User ‘Place of Safety’:

Any location beyond a perimeter which is [100] metres from the fire building or a distance of [10] times the height of such building, whichever is the greater … and … where necessary and effective medical care and attention can be provided, or organized, within one hour of injury … and … where people can be identified.

 

Where there is a Risk of Explosion … multiply the numbers in square brackets above by 4 (at least !).

 

 

 

All Fire Evacuation Routes – inside and outside a building – should comply with Accessibility Design Criteria.  This is an entirely alien concept to many Fire Prevention Officers in Local Authorities, and Fire Consultants !

 

Panic Attacks, during evacuation in a ‘real’ fire incident, exist.

 

Standard Movement Times, during evacuation in a ‘real’ fire incident, do not exist.

 

 

 

People should be able to reach an ‘Area of Rescue Assistance’ inside a building with ease.  In practice, few people understand what the word ‘refuge’ means (as in … refuge point, refuge area, area of refuge, etc).  As a result, these spaces are regularly misused and/or abused in buildings.  And there is great difficulty translating a word into other languages which, in English, can have so many meanings.  In Italian fire safety legislation, for example, ‘refuge’ has been translated as ‘spazio calmo’.  How crazy is that ?

 

So … what is an ‘Area of Rescue Assistance’ ?

A building space directly adjoining, and visible from, a main vertical evacuation route – robustly and reliably protected from heat, smoke and flame during and after a fire – where people may temporarily wait with confidence for further information, instructions, and/or rescue assistance, without obstructing or interfering with the evacuation travel of other building users.

 

 

This is a notional Area of Rescue Assistance …

 

A Clear Evacuation Width of 1.5 metres on the Evacuation Staircase facilitates ‘contraflow’ in a fire emergency (shown on the lower flight of stairs), i.e. emergency access by firefighters entering a building and moving towards a fire, while building users are moving away from the fire and evacuating the building … as well as allowing sufficient space to safely carry an occupied wheelchair down the staircase (shown on the upper flight of stairs).

 

Drawing showing a notional Area of Rescue Assistance in a Building. Click to enlarge. Based on a design by CJ Walsh. Drawn by S Ginnerup, Denmark.

Drawing showing a notional Area of Rescue Assistance in a Building. Click to enlarge. Based on a design by CJ Walsh. Drawn by S Ginnerup, Denmark.

 

 

Evacuation Skills & Self-Protection from Fire in Buildings …

A ‘skill’ is the ability of a person – resulting from adequate training and regular practice – to carry out complex, well-organized patterns of behaviour efficiently and adaptively, in order to achieve some end or goal.

 

Building users should be skilled for evacuation to a ‘place of safety’, and test/drill/non-emergency evacuations should be carried out sufficiently often to equip building users with that skill.  Consideration should be given to practicing evacuation once every month or, at most, every two months; once a year is inadequate.  In the case of people with a mental or cognitive impairment, there is a particular need to encourage, foster and regularly practice the adaptive thinking which will be necessary during a ‘real’ fire incident.

 

Since Fire Protection Measures and Human Management Systems are never 100% reliable … it is necessary for frail older people and building users with disabilities to be familiar with necessary guidelines for self-protection in the event of a fire emergency.

 

 

Assisted Evacuation & Rescue Techniques …

Firefighters have two functions:

         fighting fires ;  and

         rescuing people who are trapped in buildings, or for some reason, cannot independently evacuate a building which is on fire.

 

People with disabilities are participating more and more, and in ever increasing numbers, in mainstream society.  It is necessary, particularly for firefighters, to become skilled in how best to rescue a person with a disability from a building, using procedures and equipment which will not cause further harm or injury to that person.

 

Manual handling of occupied wheelchairs in a fire evacuation staircase, even with adequate training for everyone directly and indirectly involved, is hazardous for the person in the wheelchair and those people – minimum three – giving assistance.

 

Generally … Powered Wheelchairs are too heavy for manual handling in any situation.

 

For these reasons, all lifts/elevators in new buildings should be capable of being used for fire evacuation.  Lifts/elevators in existing buildings, when being replaced or undergoing major overhaul, should then be made capable of being used for fire evacuation.

 

Local Fire Authorities should ensure that they possess the necessary equipment to rescue people with a wide range of impairments, and that specialized rescue equipment is regularly serviced and maintained.  Every Fire Authority should have an ‘accessible’ and ‘reliable’ Emergency Call System which is available, at all times, to the public within its functional area.

 

It is essential that every Firefighter is fully aware of this important public safety issue, and is regularly trained in the necessary rescue procedures involving people with a wide range of impairments.

 

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