The threat of fire or other emergencies in high-rise buildings pose deadly fire challenges to fire department. The large numbers of persons in commercial high rise buildings, the nature of the occupancy and typical building geometry that is considered by many fire professionals presents an unacceptable risk. In reality, the fire department does not have capabilities to do much of anything above the fire floor that is beyond the reach of their super aerial ladder fire trucks. So, if a fire breaks out in a building taller than that, the consequences depend entirely on the in-built safety mechanisms. One of the in-built safety mechanisms is developing an evacuation plan.
Introduction
Fire remains a major cause of death, injury and property damage. The rise in the number of fire and non-fire related incidents such as the terrorist threats and earthquakes worldwide clearly illustrated the need for high-rise buildings to be proficient if a total and sudden building evacuation becomes necessary. But, full-scale evacuations of high-rise buildings are rare until a 'real' crisis occurs, little is known about how readily and rapidly these buildings can be evacuated and what factors serve as facilitators or barriers to the process.
In the aftermath of the World Trade Centre towers collapsed during the September 11, 2001 terrorist attacks in New York, building and fire authorities called for new research into how to construct buildings more safely and evacuate people more efficiently. There was a great deal of discussions on the need for high-rise and multi-complex buildings to be better prepared for probability of large-scale evacuations. Discussing requirements for more-frequent fire drills -- and ones that require that the whole building be evacuated rather than just certain floors -- along with a higher standard for the visibility of exit signs, emergency lighting and fluorescent markings, widening of stairwells and providing firefighters with building-information plans.
Preparedness in evacuation is not a luxury but risks reduction strategy in the post 9/11 world. Even a well-maintained intelligent or smart building with proper fire protection, security and surveillance systems cannot prevent threat of fire or other emergencies from happening. Creating emergency plans and procedures response to fire and other threats are needed to make sure all losses will be minimal in the event of worst case scenarios.
The lack of plans and procedures for evacuation can lead to confusion among the high rise occupants in the event of major emergency. The purpose of this article hopes to provide ideas on how to increase preparedness in evacuation that can help best provide for the care of getting everyone out quick in the case of a large-scale evacuation.
Lessons Learned From The World Trade Centre (WTC) Evacuations
According to the recent federal safety report, the September 11, 2001 attacks killed 2,749 people at the World Trade Centre. Out of that number, about 1,970 of the civilians who were trapped above the impact zones all died. The total number could have been as high as 14,000 had the buildings been full based on rough estimates using existing scientific models.
The extensive fire safety improvements (e.g., improved signage and better lighting in stairwells) done at the two WTC towers after the 1993 bombing were believed to have facilitated the evacuation process in the 9/11. The 1993 bombing led some employers to enhance their emergency plans, which might have helped evacuate their employees more rapidly.
An estimated 13,000--15,000 persons successfully evacuated the two towers. Yet, the fatality figures were high. Even for people below the impact zones, going down was no piece of cake, with problems like evacuation initiation delay, evacuation interruption, and encountering obstacles in the evacuation path (environmental cues) such as smoke, water, or debris. In the North Tower, it said, the average survivor took longer to descend each floor than the slowest speed cited in fire-safety handbooks that engineers use in designing buildings. It leave us all with some soul searching in respect to trying to visualize what it must have been like for those less fortunate occupants trying to escape but have no ability of walking down stairs unassisted.
Current building codes base the required number and location of exits on a ''phased'' evacuation strategy and do not assume that all occupants will leave at once. Such assumption could threaten lives. The lessons learned from the WTC evacuations revealed so many shortcomings about the building egress systems (exit stairs and refuge areas) and raised so many questions. What happened when people are trapped above a high-rise fire? How building management can best provide for the care of getting every occupant out quick in major emergency?
Ever since this tragic event, safety officials and engineers have been trying to think of efficient disaster escape plans to get as many people out of very tall buildings in the shortest possible time frame. Experts elaborate on a series of new escape systems for high rise buildings under fire (or damaged by explosions) whose aim is to bypass impassable floors or blocked stairways. These would allow people trapped in higher elevations to escape safely to the street. They consider various types of devices, including those that can be deployed inside or on the exterior walls of the building.
Duty Of Care
Just as important as making buildings accessible to people with disabilities, building stakeholder has also a duty of care to provide adequate means of escape from a building for every people in the event of a fire. The safest way to get out from a blazing high-rise building is via the protected staircases and make way down. Lifts are deemed to be unsafe for use in fire situation and should never be use for fire evacuation. Super aerial ladders from the fire truck are not the sure way out of a burning high-rise because they have their limits.
But what constitutes adequate care if people have difficulty in identifying or getting to the escape routes in case of complete darkness due to power outage. Further, it is estimated that about 20 percent of the building occupants living or working in high-rise buildings would have difficulty in evacuating a building if they could not use the lifts during an emergency. Stairway evacuation is almost impossible – not just for people in wheelchairs, but also for people with walking difficulties, heart disease, epilepsy and so on. The building managers today face new challenges to do more to ensure safer and quicker escape of all occupants. What are the facilities needed for aiding evacuation? What alternative means of escape are available to both the able bodied and to those with disabilities?
Facilities For Aiding Evacuation
The objective of evacuation preparedness attempts to tackle the perceived difficulties and problems of evacuation and to assess the need to provide adequate facilities for aiding evacuation.
For example, a person who has to decide how to get out of a burning building is likely to be under significant psychological and even physical stress if he/she cannot locate the escape routes during the power blackout. Identifying the escape route is fundamental to ensuring egress is effective and efficient even in complete darkness. For an escape route to be effective it is important that from anywhere in the building occupants have sight of a sign, or series of signs, which leads them to a place of safety. The visibility of escape route signs will assist firefighters and other rescue teams to evacuate occupied areas during emergency situations. For instance, evacuees and firefighters using unfamiliar escape stairways that lead to other floors or transfer corridors giving access to separate buildings need total confidence in their location and which floor they are on at any point of time during an evacuation. It is vitally important therefore, that these stairways are clearly identifiable even in complete darkness and that each floor access is clearly numbered.
For these reasons, the provision of adequate facilities for aiding evacuation in buildings hopes to provide better opportunity for a safer and orderly evacuation of the building to everyone in case of an emergency. Some of the facilities that are available in the market that the author has knowledge of when writing this article are:
1) An audible and visual fire alarm system is to warn people of an emergency and provide a general-purpose evacuation warning.
2) An adequate communication systems (e.g., public address system, inter-com system, and lifts telephone system) is to minimize heavy congestion on stairways by directing evacuees to move to a less congested staircase, and to quickly rescue those trapped inside the lifts.
3) Fire vents that open automatically in the event of a fire, maximize fire containment and life safety and minimize damage and material loss. The vents help to improve visibility inside the building to help occupants escape the fire and reduce the risk of smoke inhalation.
4) Creating better and safer protected staircase design, such as: increasing the width of doors, width of stairs, number of exits, add on anti-slip nosing on steps of stairs, improved emergency lighting and smoke control in stairs.
5) The exterior fire escape stairs provide alternative egress for occupants and can also provide firefighters with access to, and escape routes from, upper floor of the fire building, when interior stairs are sometimes untenable or inadequate.
6) Emergency escape lighting, signage and safety way-guidance system, both for electrically powered components and for photoluminescence components, should be capable of being activated as directional information signs in all risk situations, for examples where there is a power outage and where smoke is present.
7) Personal ‘escape smoke hood’ can protect user for safe escape from smoke and fume during fire evacuation.
8) Portable and lightweight evacuating chairs may be needed to help wheelchair users up and down stairs. This special designed evacuation chair enable trained helpers to move people with physical handicaps down a flight of stairs much easily that might not otherwise be possible. However, it can also slow stairwell traffic if travel dozens of floors during large-scale high-rise evacuation.
9) Ramps can be helpful for wheelchair users in negotiating one or two steps.
10) Only special designed evacuation-lift that is approved for used by the fire department in fire evacuation.
11) Only those escape chutes that permit safe evacuation in fire situations approved by a fire research-testing institute for fire protection will give every person the ability of self-reliant escape. Escape chute systems that can be deployed strategically inside or on the exterior walls of high rise buildings, allow people trapped in higher elevations to bypass impassable floors or blocked stairways to escape safely to the street, when building under fire (or damaged by explosions).
Provision of the appropriate facilities to facilitate evacuation will not only ensure all people have equal opportunity in evacuations but the speed of egress will also be improved. More importantly, reduce the hazards of evacuation and maximize the escape potential of people with disabilities of getting out alive.
Developing Evacuation Plans
Evacuation plans in general have always been an important operating feature of a building. Given that buildings have differences in structure design, construction, fire-resistant qualities, height, floor layout, usage, occupancy load, each building presents unique problems in emergency evacuations. For this reason, the fire department acknowledges that there is not a single recipe for handling evacuations for any one building, but the key is communication between building operators and firefighters.
A typical requirements of an evacuation plan should include floor plans and diagrams for evacuation routes, procedures for reporting emergencies, spell out occupant and staff response, include fire drills, and detail the type and coverage of a building's fire protection systems and other items required by the authority having jurisdiction. If additional facilities such as equipment and escape devices that are available for aiding evacuation and rescue, it should also be included in the evacuation plan.
Evacuation plans must account for a range of events and be robust enough to take all types of occupants into consideration. Plans should include floor search to make sure that every person on a floor is aware of an emergency evacuation. The orderly movement of persons requires the utmost coordination of assigned emergency evacuation floor teams and central evacuation control. They must be encompassing, amenable to change, and applicable to a range of occupants with disabilities. For example, floor plans with considerable detail reveal the number of people who work in a specific office and whether or not that office has someone with special needs. Such floor plans that are available to on scene commanders of the fire department would be an extraordinarily valuable tool for firefighters.
Evacuation planning should take into the consideration of how people will realistically react in an emergency situation. Lives are often lost through the irrational behavior of evacuees triggered by panic. Successful evacuation is partly dependent on physical ability of individuals and other physical values, such as distance to travel, proportions of exits and density of smoke and partly on psychological values, such as communication processes, perception, conceptualization, understanding, evaluation and decision. Because of this, proper education of occupants on abiding to evacuation procedures and escape routes hopes to eliminate panic when people are ignorant during an emergency evacuation.
The building calling for an evacuation when there is a known event. Not in every instant is there a need to evacuate the entire building. However, there may be no stopping of building occupants who choose to evacuate on their own. An improperly ordered evacuation in a high rise blaze can send people into a smoky stairwell where they may be trapped by locking doors. Because of this, only properly trained building manager or the chief engineer is authorized to order an evacuation on occasion when they have to make a decision ahead of the fire department.
In the event of a fire at high-rise building, the building manager or the chief engineer should have the assigned authority to order evacuation of a given floor or several floors of the building to a refuge location prior to the arrival of the fire service. Additional floors, as well as total evacuation, may be evacuated at the direction of the local fire department. Plans for evacuation during ‘bomb-threat’ or ‘non-fire’ related emergencies should be controlled by joint decision of the police and fire department in consultation with building management and tenants’ representatives. In addition to evacuation by means of staircases, the use of lifts for ‘bomb threat’ emergency evacuation can also be considered, but never for fire and earthquake emergencies.
Building control will determine the safest and most efficient means of evacuation, depending on the nature of the emergency and scope of damage. For examples, Plan-1 for evacuation during fire emergencies should be accomplished by means of fire staircases and make way down. Plan-2 for alternate routes when particular circumstances warrant rerouting of occupants because of hazards, such as smoke, heat, and gasses in the evacuation route. Procedures should advise skyscraper occupants never to flee towards the roof in a fire emergency because hot gas and smoke rises. The only exception to this rule is if the building has made provision of escape chute at the rooftop as an alternative means of escape route to reach the ground.
Lastly, it is the building management’s responsibility and duty of care to ensure that the building evacuation plans can evacuate as many occupants including the less fortunate prior to the arrival of the fire department. If the system fails, the firefighters will then have to come to do a search and rescue for those left behind. From time to time, an evacuation plan shall be reviewed and updated as required by the authority having jurisdiction.
Developing A Disability Evacuation Plan
A disability evacuation plan will not be complete without addressing the survival needs of people with disabilities during an evacuation. What stakeholders can do is where obstacles or physical features of a building makes it impossible or unreasonably difficult for disabled people to access/egress, building management must take reasonable steps to remove or alter the feature or provide a reasonable alternative method of overcoming the problem.
Depending on the type of building and its obstacles, such as stairs, certain equipment and signage may be needed. The provision of appropriate facilities to help those individuals who are not willing, or able, to walk down long flight of stairs due to impaired mobility or health reasons will maximize their escape potential in getting out alive. All primary function and public areas should have evacuation signs showing the means of egress and multiple paths of travel if the path to be taken by someone with a disability is different than the one used by the general public. Signs are for directional purposes and should be simple for people to follow even under complete darkness.
A building's evacuation plans should include the designation of people willing to provide assistance to those who need help and their training in the type of evacuation devices supplied to facilitate speedier evacuation, save injury to evacuees and firefighters. Emergency evacuation floor teams should have a current list of all visitors and occupants with physical handicaps, including those persons who cannot use stairs because of temporary illness or other impaired physical conditions. Unless the risk level of the emergency called for a total evacuation of all building occupants, fire wardens should simply evacuate their floor or area as normal and guide this group of occupants to a safe area of refuge. Depending on the life threat level of the emergency situations, at some point, rescue workers may have to get the disabled people out from the refuge location.
Fire authorities recognize the difficulties of evacuating people from high-rise buildings, especially elderly and disabled people in extreme emergency situations. Some fire departments have even approve the use of fire lifts for evacuation of people with mobility impairments, while others deem this method too risky. If the lifts are in service during emergencies, the evacuees should be moved down the staircase to the uppermost floor served by an uninvolved lift bank, and then be moved by lifts under the direction of firefighters. But if the lifts are not in service, the only way down is to move them via the stairway.
Evacuation Drills
The purpose of an evacuation drill is not a test for egress efficiency but enable building management to see how effective the plans and fire training have been conducted, identify problem areas and highlights things that should be better. Such practices hope to eliminate panic when people are ignorant during an emergency evacuation.
Combine training with drills should be conducted often enough to allow occupants to become familiar with the emergency procedures, and for building staff and fire wardens who must practice their duties to ensure an orderly evacuation in case of fire, panic, or other emergency. They should also be taught how to use portable fire extinguishers, in-door fire-hoses, ‘egress facilities’ if any, such as evacuation chairs and the escape chutes properly.
An evacuation drill programme should be established for periodic practice of ‘progressive movement’ and ‘total movement’ of occupants under varying conditions not restricted to fires. When drills are held, all occupants must know how to evacuate via routes that deviated from their normal paths and actually entered their designated staircases.
The myth of evacuation time taken to empty a tall building during a fire drill cannot be a determine factor of how long it will take to evacuate the structure under actual emergency situation. When the real emergency occurs, the speed of egress can vary greatly depending on many factors, including the number of occupants, their mobility, their reaction and behavior, visibility and accessibility of escape routes, dimension of the egress components and the distance they must travel. Will the building staff and fire wardens know what to do and perform their duties well? Are evacuation facilities in good working conditions to facilitate speedier evacuation?
Conclusion
Evacuation planning takes a ‘total approach’ at all levels: the individual, organizational, and building environmental. Preparedness in evacuation is a proactive and efficient state of readiness for a full-scale total building evacuation. Pre-planning, adequate communications capabilities, evacuation priorities and proper skill drills help eliminate mistakes and misunderstanding in coordination during actual emergency evacuation. Adequate training in the proper use of equipment and facilities for aiding evacuation should be incorporated as part of the evacuation drills.
Lives are not saved by codes; they are saved because people will have decided, with the help of codes, to assume responsibility for their own safety. For example, protected staircases are legal in many jurisdictions but cannot guarantee that everyone can walk down the stairs quickly without injuries during emergency evacuation. In the context of the fire code, it is not required to provide facilities in a building for escape or rescue purposes. But facilities such as escape chute could have save more lives in extreme emergencies if stakeholder chose to provide them to enable more people to get out quickly where they are not required by law.
Measuring the success of a preventive program is difficult. Nevertheless, prevention and proactive is the key objective, not reactive. A building’s level of fire protection and preparedness for evacuation holds the highest level of importance for safety of the occupants and property within. Voluntary actions by stakeholders to enhance the level of safety and responsible actions taken by individuals to meet real threats have always been the best way to advance the cause of safety and preparedness for evacuation.
This article is contributed by Escape Consult Mobiltex (S) Pte Ltd - www.escapeconsult.com
