Gulf Construction Online - High-rises need better fire safety

Fire Protection

Dubai’s skyscrapers ... redefining safety.

High-rises need better fire safety

High-rise construction brings with it a new set of fire hazards that the Gulf region must address to ensure the safety of occupants, says Robert Triozzi,* the founder of the Fire Rescue Development Program (FRDP).

01 March 2006

With developers in the GCC redefining skylines with each passing day, the importance of revising the guidelines for fire safety in these structures has become more pronounced.

Taller buildings bring with them a new set of problems and inherent risks that are different from what can be expected in buildings less than 20 m in height. Hence, there must be the political will to provide for high-rise fire safety that is commensurate with the desire to build the multi-storeys in the first place.
The threat of a fire in high-rises is still very real, despite the availability of sophisticated and high-tech automatic fire detection and suppression systems. This is as true for a fully-occupied structure as much as it is for buildings under construction or in a phase of renovation.
There are many questions that must be answered to determine just how safe our high-rises are:
•  Are the buildings built to a specific code that takes into consideration, specific high-rise problems?
•  What are the problems that could be encountered on the upper floors of a structure in the event of a fire?
•  How do high-rise fires in hot climates differ from those in cooler temperatures?
•  How capable are we in effectively evacuating high-rises, in the event of a fire?
•  How prepared is the local fire service to handle a fire 50, 100 or many more metres above the street?
•  Is the building management and staff adequately prepared and trained to effectively handle a high-rise fire situation?
•  Are the building’s occupants aware of fire prevention procedures and practices and how to escape to safety, in the event of a fire?
•  What will the political and economic repercussions be for the region, subsequent to a devastating skyscraper fire?

Building construction law
Let us begin with the main criteria used to construct a high-rise. A building construction code law, that requires all buildings higher than 20 m to provide for safety measures and easy evacuation of the occupants of the building must be enforced. These measures should include early fire detection, prevention of fire spread – both vertically and horizontally, allowance for easy evacuation, rapid access by the fire service and the inclusion of fire suppression systems in the building.
However, presently in many parts of the GCC, the ‘code’ applied in fire safety measures are only what the conscience of the architects and designers dictate, which is not good enough. There must be stringent laws that stipulate that these skyscrapers be built according to a strict code and standards specific to high-rise construction.

Problems in fire-fighting
There are many problems encountered in a high-rise, relating to structural integrity of the building, the efficiency of an automatic suppression systems, the evacuation of the building occupants as well as access to the fire by the firefighters.
Today, the trend in the building construction trade is to build lightweight structures but this almost always diminishes the resistance a structure has with regard to high temperatures. The supporting structure of the building must be well protected and have long resistance to high heat, as structural integrity is dependent on how and how well the building is constructed.
The efficiency of an automatic suppression system depends on how well maintained the systems and their back-up systems are and whether there are any obstructions, such as accumulated files, shelves and cabinets that may impede the extinguishing agent from reaching its objective.
The timely evacuation of people from a high-rise building will further depend on various factors such as the type of occupancy, the height of the structure, the number and width of the fire stairs, the efficiency of the building management and staff and most importantly, the level of training and familiarity of the occupants with regard to alternative exits to egress the structure.
The higher the building and the fewer the number of stairwells, the more the time required to evacuate the structure and for firefighters to reach the fire. Occupants trying to leave the building, a lack of “firemen service” elevators and the “stack effect” usually hamper access to the fire by the firefighters.

Stack effect
The stack effect is a phenomenon that occurs during high-rise fires in hot climates. Under normal conditions, the air entering a building is heated and rises, but in hot weather, what enters the building is hot air. In a fire above the seventh or eighth floor, or roughly 20 m, with the HVAC shut down and temperatures exceeding 32 deg C, the air, and therefore smoke, no longer rises.
The smoke that is continually accumulating from what is burning may remain where it is, that is, “stack up” or actually fall to the floors below the fire. It should be remembered that smoke is made up of tiny particles that are the unburned products of combustion. Being a solid matter, it is heavier than air but will rise during a fire forced by the convection of hot air pushing up from the heat of the flames. When there is no longer a vertical convection, the smoke will fall.

Logistics
Another major problem that firefighters face is the logistics of getting the resources to the fire floor in order to be able to fight the blaze. This can be a monumental task requiring time and manpower. Other difficulties that firefighters must be overcome difficulties include falling glass that may injure or kill them and cut hose lines, communications hampered by concrete and steel of the structure and the distance from the street, low water pressure on the upper floors and sheer physical exhaustion.

Lack of firefighting experience
The firefighting forces must be up to the challenge of combating a blaze many meters up in the sky.
Firefighting is a highly skilled profession that requires exceptional qualifications in those that perform it. Firefighters must be exceptionally fit, well educated, be able to think on their feet and calculate risks and make decisions. Currently, in most of the Gulf countries, some 80 to 90 per cent of fire officers are local nationals, while the firefighters are primarily unskilled guest workers. Many of them do not have the necessary prerequisites to be a professional firefighter.
There is also a lack of experience in the Gulf countries. Unlike Europe or North America, there is no long fire service tradition that has been handed down from one generation to another, permitting the “old-timers” to pass down knowledge gained on the fireground to the new recruits. Everyone is learning as they go, as this is new to all. This lack of practical experience will definitely have consequences on the effectiveness of the fire service department in rescue operations in skyscrapers.
One must also examine what the fallout from a high-rise fire will be regarding the general economy and image of the region, in terms of the future. A fatal high-rise fire will cause many to have second thoughts about investing in an area that seems unsafe and where the fire service personnel are perceived to be inadequate to effectively handle the challenges they face.
Many of the problems and concerns outlined here may be overcome. However, the desire to do so must be felt by all the protagonists involved, including the building construction industry personnel, engineers, architects, building managers, the fire service and above all, the government.
Laws that deal specifically with the construction and maintenance of high-rise buildings must be elaborated and enforced. Managers and occupants of the buildings must be prepared and trained to conduct themselves in the event of a fire on the upper floors. The fire services must be sustained and supported heavily by being given proper training along with the human and material resources necessary to tackle a high-rise fire.
If we begin to act on these points then we can be assured that the high-rise development in the GCC will create a safe investment and environment for all.
* Robert Triozzi has been fighting fires since December 1975 and has worked with fire-fighters in over 30 countries on five continents, serving in various capacities including being the United Nations fire chief. He now heads the FRDP, an international, non-governmental organisation comprised of fire officers from 12 countries whose mission is to train and reorganise fire services in developing and war- torn countries.