The Burrabazar fire has swivelled the spotlight on fire safety measures in highrises.

A fire can wreak more havoc in a tall building because heat does not dissipate easily into the atmosphere. The heat remains trapped within the structure, increasing the temperature not only on the floor of the origin of the fire but also on those above and below.

However, most deaths occur because of excessive inhalation of smoke and other toxic gases like carbon monoxide and cyanide fumes. Thick smoke also makes visibility poor, paving the way for disorientation during evacuation or escape.

Propertt looks at the critical factors in fire-protection and firefighting in highrise apartments:

Arrest spread

Fire generally spreads through conduction, convection or radiation, engulfing the floor of origin and finally floor after floor.

The common passages through which fire/smoke/heat spreads from one place to another are unsealed vertical service shafts, ceiling voids, air-conditioning ducts and openings like doors, windows and ventilators.

Another important phenomenon known as “stack effect” in highrises is attributed to the spread of smoke, followed by smoke-logging, in areas away from the seat of the fire.

Protection systems

These can be divided into two categories, passive and active.

Passive protection systems can be attained through the following measures:

Compartmentation: The objective of compartmentation is to limit the size of the fire and thus the losses. This also aims at arresting the spread of smoke, which enables the occupants to get more time to escape. The extent of compartmentation in any building is determined by taking into consideration fire insulation, which is a major element in preventing transfer of heat from one side to the other.

Non-combustible materials: The selection of building materials should be based on their “ignitability” and combustibility. As far as feasible, only non-combustible materials should be used in construction and furnishing.

Electricity: Calculate the total requirement of electrical fixtures and get adequate power to avoid overload and short-circuit.

Active fire protection systems can be attained through:

Detecting and communicating fire conditions. Automatically activated fixed firefighting installations like automatic sprinkler system, CO2 and total-flooding system, and water spray system are available

Alerting and aiding occupants who are required to evacuate the building. Manually operated electric fire-alarm system, talk-back system and public address system are useful

Emergency steps

In the event of fire, highrises should ensure the following measures without loss of time.

Informing the fire brigade and similar agencies

Automatic return of elevators to the ground floor

Starting of water pumps and emergency generators

Activation of automatic suppressing equipment

Directing people’s responses

Closure of fire doors

Pressurising the staircases and lift lobbies

Controlling air-conditioning system to prevent smoke spread.

Safety manual

A fire safety manual or ‘Fire Orders’ helps the building management to establish and carry out procedures in an efficient manner. This may differ from building to building, but the essential features are:

Formation of a group of occupants with clearly defined and delegated responsibilities, authority and accountability for effective use of human resources

Identification of risk and communication to occupants

Designing a contingency plan that prescribes dos and don’ts in case of an emergency

Periodic drills to shortlist the errors in the response of occupants and staff and building confidence in the fire-protection system

Good housekeeping practices that help minimise the outbreak of fire and keep escape routes free from obstruction

Maintenance schedules for fire-protection systems to retain their operating efficiency

Staff training to ensure correct operating procedures (without panic) after detecting fire, raising an alarm, informing the fire brigade, assisting in evacuation, reporting of faults and use of active fire-protection equipment

Safety audits to check regular implementation of fire-safety management procedures, status of passive fire-protection measures, functionality of active fire-protection equipment, adequacy of fire-protection equipment in case of additions and alterations to floor geometry and training level of members and occupants in housekeeping practices.