Another area where disabilities impact emergency egress is with mobility limitations. This is most frequently associated with wheelchair users. It’s important to be sensitive to the fact that wheelchairs represent mobility and are frequently fitted to accommodate the specific physical needs of the user. Thus, whether evacuated with or without their wheelchairs, these people will need their own chairs when they reach safety — for both physical and psychological reasons.
There are several types of controlled descent devices that can be permanently installed within stairways to accommodate wheelchair users. In some, the individual transfers from the wheelchair to the portable controlled-descent chair. Some models permit a relatively small person to transport a larger person, while with other devices the individuals ideally should be about the same weight. These chairs are designed to travel down stairs on special tracks with friction braking systems, rollers or other devices to control the speed of descent.
Another type of controlled descent device is designed so the wheelchair user moves the wheelchair onto the transport device and the wheelchair is secured. The advantage of this device is that the wheelchair user does not have to transfer from the chair — a situation that will be more comfortable and reassuring.
Always consult the wheelchair user as to the selection of an emergency evacuation chair. The advantages or disadvantages of these devices are dependent on the capabilities, acceptance and understanding of the end user(s). The effectiveness or failure of evacuation chairs as a rule can be attributed to the fact that the wheelchair user was not consulted on equipment selection. Chairs that do not accommodate the physical needs of the user create problems, which may lead to a refusal to use them in an emergency.
A three-person, assisted wheelchair-carry device, called "Evac-u-Straps" was developed by a wheelchair user. It consists of wide padded leather wristbands with Velcro closures equipped with large metal grasping hooks. The hooks are designed to attach to both sides of the front of the wheelchair. People on either side of the wheelchair grasp the straps and are assisted by a third person behind the wheelchair, keeping it slightly tipped backwards. The wheelchair user assists by hand-braking the wheels.
Garaventa Evacu-Trac. Developed in Switzerland. Convenient, top-of-stair storage. 1. Brake system engages when lever is released; 2. Adjustable safety belts; 3. Rubber tracks grip stairs; 4. Eight auxiliary wheels for smoother ride on flat surfaces, such as stair landings. Designed so a passenger’s weight propels it down stairs. Governor limits the maximum descent speed.
Evac+Chair '300-H.' Folds for on-the-job storage. Can be readily available for emergencies. Unfolds/opens quickly and weighs only 15 pounds but has a 300-pounds capacity. Cantilevered design places seat inches above stairs. Other features: sliding head rest, quick-release safety belt buckle and instructions permanently stamped on back. Changes the obstacle of fire stairs into usable escape route for all, e.g., pregnant women, frail persons, employees with limited stamina or someone with a temporary disability.
Scalamobil. Stairclimbing and power unit, invented in Germany. Three-step process for use. First, attach handles to the Scalamobil. Second, attach Scalamobil to wheelchair. Third, begin operation. 12V/12AH power base. Operator’s safety features include: automatic mechanical security brakes on every wheel; variable speed control from six to 12 steps per minute and ability to park the wheelchair safely on any step during ascent or descent. Designed to negotiate most stairs, from the extremely narrow to curving circular stairs.
Most people are familiar with the fact that elevators are not to be used for emergency egress and are so marked in most buildings. Elevator codes require that when smoke detectors in elevator lobbies activate, the elevator is recalled to the ground floor (as long as the ground floor smoke detector is not the one that alarmed) and is taken out of service. The fire department can operate the elevator with a special key and may use it to move its people and equipment, or for evacuation of occupants. This means that without the fire department, people with disabilities are relegated to the stairs or must await rescue.
In recent years (especially since the 1993 World Trade Center bombing), there has been a growing interest in providing elevators that can be used for emergency evacuation. In a study conducted for the General Services Administration (GSA), NIST found that the use of both elevators and stairs can improve evacuation times by as much as 50 percent over stairs alone.
However, elevators that are used for emergency evacuation need to be specially designed to assure their reliability and safety during a fire. NIST research has shown that it is feasible to design elevators that are safe to allow continued use in emergency evacuation as long as the following features exist: enclosed lobbies at each floor that are pressurized through the shaft so both remain smoke-free; dual power systems for reliability and water-resistant components to prevent failure due to flooding of the shaft by firefighting water. (Feasibility of Fire Evacuation by Elevators at FAA Control Towers, NISTIR 5445, 1994.)
A number of unique escape devices have been developed over the years. These include controlled-descent devices using cables and chutes of various types. The cable devices usually use a strap or chair secured to the cable by a device that is squeezed to allow descent. The more it is squeezed, the faster the descent. Letting go stops the descent. However, most people are reluctant to evacuate down the outside of a building.
The chutes may be solid or flexible fabric tubes that generally rely on friction to control speed. They have the advantage that they do not let the user see out, so they are more acceptable than cable devices. However, their acceptance in practice in the U.S. has been limited. There is little information available as to the performance of these devices in emergency situations. These unique specialized escape devices generally have serious shortcomings. (Egress Procedures & Technologies for People with Disabilities. Final Report of a State of the Art Review with Recommendations for Action, ATBCB 1988.)