Detrainment device

A Detrainment device is equipment on a rail vehicle that provides an evacuation route for the passengers. It usually consists of a set of steps or a ramp, located at a doorway, allowing passengers to leave the vehicle in an emergency, vehicle breakdown or accident.

A detrainment device is moved from a stored location into an operational position, usually above the coupler at the end of a passenger car. A detrainment device may consist of a manually placed, hinged, foldable or telescopic ladder or ramp. A detrainment device may allow evacuation to track level, or to a coupled railcar. A detrainment device may be fitted with handrails.

In other cases, evacuation may be via the vehicle passenger side doors to a trackside walkway in a tunnel, without the use of a detrainment device.

Types
Examples of the main types of detrainment device currently in service include:

a) Steps, stored loose inside the driver’s cab or the passenger saloon
 * Historically the most common arrangement

b) Hinged steps, stored inside the driver’s cab or the passenger saloon
 * London Underground S-Stock

c) Steps, folding, hinging or sliding out from the doorway
 * London Underground refurbished 1973 Tube Stock
 * London Underground 1996 Tube Stock
 * Bombardier Class 378 Capitalstar

d) Ramp, sliding out from below the doorway
 * London Underground Central Line 1992 stock

e) Ramp, folding out from the doorway
 * Kawasaki Heavy Industries C151 – Singapore MRT
 * Alstom Metropolis C751A – Singapore MRT
 * Skyfall Line rolling stock that is Hyundai Rotem

f) Tensioned Fabric ramp, deploying from the doorway
 * Siemens Modular Metro – Bangkok BTS Skytrain
 * KTM Trains (Class 170s and Class 390s)
 * Bombardier C981 - Singapore LTA Downtown Line
 * Alstom Metropolis C830 – Singapore MRT

Performance
User trials on prototype equipment in controlled conditions have indicated that a wide detrainment ramp will allow the evacuation of 2500 passengers in 28 minutes if the ramp, its handrails and the cab and saloon throughways are correctly specified. Modern detrainment step systems can detrain one person every two seconds.