Fire Safety: A Sociological Perspective

1. Fire Safety: A Sociological Perspective Graham Spinardi Ove Arup Foundation/Royal Academy of Engineering Senior Research Fellow in Integrating Technical and Social Aspects of Fire Safety Expertise and Engineering 4 June 2013

2. How is Fire Safety Social? • How individuals, families, colleagues, etc cause and respond to fires • (Lifestyle, poverty, arson) • Evacuation • How society (and groupings within) prepare for fires • Regulation • (Fire services) • How experts know about fire and fire safety • Induction from testing and from actual fires • Deduction from theory (eg fluid dynamics)

3. Regulation • Origins in major disasters • Great Fire of London 1666 => no thatch, less wood, 2 hour party walls, no projecting roofs • Edinburgh Empire Palace Theatre Fire 1911 => 2½ minutes evacuation time • Insurers and suppliers • National Fire Protection Association (NFPA) origins in 1895 meeting of insurers and sprinkler manufacturers - need for standardisation of sprinkler installation • Self-regulation? • Comparison with aviation (see John Downer’s work)

4. Regulatory Barriers • Prescriptive building regulations/codes – to slow fire spread, aid evacuation, facilitate rescue • Testing geared towards the regulations • Inflexible and not responsive to new materials & building techniques, limits use of difficult spaces, adds cost • => Shift from rigid code compliance to Performance Based Design (PBD) • ‘Assess the effects of fire from first principles early in the design’* • Computer power to model fire and smoke fluid dynamics, structural outcomes, and evacuation behaviour (quantitative and graphic outputs) *Florian Block, 'Structural Fire Engineering of Unusual Steel Structures'

5. Performance Based Design Issues: Expertise and Professional Standards • PBD is more flexible, but needs regulators to have expertise and/or to trust outside review – not just ‘code-checkers’ • Difficult to do if authorities have little expertise • Problematic if regulators are weak, if professionals lack standards of behaviour, and if link with socially-agreed level of safety is lost – e.g. parts of Australia versus San Francisco’s ‘local equivalencies’ to the code

6. PBD, Risk, and Judgment • Acceptable levels of risk • Perceptions vary according to whether seen as voluntary, controllable, catastrophic • Most deaths in domestic homes but little regulation, whereas few deaths in high-rise building but heavily regulated • Prescriptive regulations reflect social consensus, outcome of local governance • PBD can make safety a matter of judgment • ‘guidance is almost exclusively qualitative in nature … can lead to inconsistent levels of safety’* • Also need judgment on reliability of the science * Fleischmann, 2011, 'Is Prescription the Future of Performance-Based Design?'

7. Learning from Fires • Complex circumstances (many variables, not controlled), not fully documented • Rare for some classes of building (eg modern high rises), each example unique (different designs, materials, regulatory regimes, etc) • Lack of instrumentation • Evidence more or less destroyed

8. Fire Safety Knowledge and Testing • Controlled, but therefore not realistic • Test design – elements tested in isolation • Underlying theoretical assumptions • ‘Similarity judgments’ about whether test is sufficiently similar to real-world situations • Expensive to build and burn anything like a realistic building • 1990 Broadgate fire => Cardington tests • 2006 Dalmarnock Glasgow fire tests • ‘Standard’ tests central to regulatory regimes • ‘test individual components of structures in a fake scenario with a fake fire’* * Luke Bisby, March 2011, Ove Arup Foundation interview

9. Cardington Airship Hanger

10. Fire Safety Knowledge and Testing • Controlled, but therefore not realistic • Test design – elements tested in isolation • Underlying theoretical assumptions • ‘Similarity judgments’ about whether test is sufficiently similar to real-world situations • Expensive to build and burn anything like a realistic building • 1990 Broadgate fire => Cardington tests • 2006 Dalmarnock Glasgow fire tests • ‘Standard’ tests central to regulatory regimes • ‘test individual components of structures in a fake scenario with a fake fire’* * Luke Bisby, March 2011, Ove Arup Foundation interview

11. Standard Fire Resistance Test • Method stems from early Twentieth Century • e.g. ASTM (American Society for Testing and Materials) E119 • Building element (eg column or floor) subject to heating according to standard fire temperature-time curve • Does it maintain load-bearing, integrity and insulation for long enough?

12. Criticism of Standard Fire Test • ‘The difference between the standard test temperature-time curve and temperature-time curves measured in real compartment fires is considerable.’* • Does not take account of windows, ventilation, compartment shape and size • Elements tested in isolation though in building will be joined to other elements thus spreading heat *Barbara Lane, 2000, 'Performance Based Design for FIre Resistance.'

14. Fire/Smoke Dynamics • Fire Dynamics Simulator (FDS)/Smokeviewvisualisation software • Widely used for PBD(free, developed by US National Institute of Standards and Technology) • How good is this software for smoke and fire prediction? Do users understand limitations? • A priori simulation of Dalmarnock tests showed that ‘current modelling cannot provide good predictions of HRR [heat release rate] evolution (ie fire growth) in realistic complex scenarios’* • Powerful tool for demonstration – could visual nature be overly persuasive to non-experts? * Rein et al, 2009, 'Round-robin study of a priori modelling predictions of the Dalmarnock Fire Test One’

15. Performance Based Design Issues:Trade-offs • Active measures (sprinkler system, smoke control) can allow passive measures to be relaxed (size and height of compartments, distance to exits, fire resistance of materials) • Enables innovative design, use of difficult spaces (eg new San Francisco Exploratorium in old Pier building) • But important that active measures have sufficient redundancy (eg sprinklers in domestic housing in California may not work after earthquake)

16. Fire Safety and Human Behaviour • Do quantitative simulations used in PBD produce spuriously accurate results? • Simulation models provide quantitative (and visual) results that may gloss over limited basic understanding (are ‘first principles’ enough?) • Human behaviour is simplified or ignored

17. Maintaining Fire Safety • Who is responsible for assuring that fire safety features are maintained during a building’s life? • In many jurisdictions, regular inspections, including operational demonstrations of equipment • In UK, shift now to ‘responsible person’ and reliance on fire safety audits • Critical issue when buildings are modified (eg six deaths in Lakanal House tower block, Camberwell, July 2009) • PBD-based buildings may incorporate active features that need to be maintained