Fire-fighting & Rescue in Buildings with Engineered Solutions

Roy WilsherDirector Community Protection

& Chief Fire Officer

Fire Engineering is the application of scientific and engineering principles, rules [Codes], and expert judgement, based on an understanding of the phenomena and effects of fire and of the reaction and behaviour of people to fire, to protect people, property and the environment from the destructive effects of fire.

Definition

Modern Buildings

• Traditional design limits designers and engineers of large innovative buildings

• Designers and engineers are actively seeking more cost effective solutions

• Are today’s buildings potentially more hazardous to Firefighters?

The Issue

Modern Buildings

• Information on buildings not being passed to Firefighters

• Focus now on community fire safety

• Advent of self assessment

• Maintenance of Knowledge

What are the issues?Facades/insulation

• Glazed panels from floor to ceiling level

What are the issues?

Ventilation – in a fire, how can you

effectively ventilate a compartment

when there are

no external

openings?

What are the issues?

Large open spaces

What are the issues?Compartment sizes

Galleria Harlequin

Westgate

Howard Centre

Marlowes Jackson Square

Firefighter Override Controls

What are the issues?

Horizontal Dry Risers and Poor Fire Service Access

What are the issues?

Increased travel distances

• Corridor length - 7.5m• Can go to 17.5m• Compensatory features

(Automatic ventilation)

What are the issues? Innovative construction products & techniques

What are the issues?

Timber framed construction

Timber framed construction

Rapid fire development

False Chimneys

Two Hertfordshire Examples

News International, Cheshunt

News International, Cheshunt

News International, Cheshunt

Hillmead School, Bishop’s Stortford

Operational ConsiderationsSummary of risk critical

information• Incomplete evacuation likely: ‘persons reported’• Excessive noise levels: FA & mech. vents• Excessive firefighter penetration distances• Min. smoke level 2.5m• Intense radiated heat (200ºc at 2.5m)• Fire size > 5MW (‘good’ car fire): beyond smoke

control design criteria: total smoke logging could lead to flashover Fire size > 216m² (½ a tennis court): beyond sprinkler (& smoke control) design criteria

• Ensure entrance doors remain open (for inlet air)• Do not shut down sprinkler system.

Operational Considerations (cont.) Summary of risk critical information

• Smoke entering/exhausting from > 1 reservoir indicates system/s failure: dangerous conditions.

• Smoke control equipment rated at 300ºc for 1 hour• West Gate, Marlowes and Jackson Square sprinkler

systems fed from town main: use of incorrect hydrants could lead to supply failure/building loss

• Harlequin, Galleria and Howard Centre sprinkler systems on tank supply: 1 hour duration at the max. design capacity of 18 heads/216m² (½ a tennis court)

• Danger of backdraft, ‘blow-torch’ effect from fire in ‘sealed’ shop units out of hours (Marlowes, Westgate, Howard Centre and Harlequin). Consider overriding mechanical smoke control system.

What can we do?

• Ensure information is shared

• On Site Expertise

• Training – practice!

• Operational planning

• Involve Firefighters

• Changes to the building when in use compromises design & Firefighters!

What else needs to be done?• An effective testing regime for building

materials to ensure buildings are safe, not only for the occupants, but also for Firefighters

• This should include testing in their ‘as built’ format in realistic conditions

• Information to local fire service (manual)

Thank You

Questions