Passengers do not want to contemplate the worst case scenario of emergency access requirements but in this safety critical environment every detail has to be fully considered and in the split seconds that an emergency escape situation provide, the last thing either passengers or rescue services want to be confronted with is a jammed internal door.
The specification required access through the door irrespective of any angle at which the carriage might subsequently be inclined and assuming the mechanism has jammed or been obstructed after an incident the only options are to either kick the door through or disassemble it in some way. The most important element in this design is to allow the escapee or rescuer a smooth edged exit through which to pass in keeping with the sectors stringent safety regulations and emergency planning. But how could this be done in a way that maintains the structural integrity for use in the thousands of ordinary everyday door openings? The door designers came up with a deceptively simple yet innovative solution. By the addition of a ring pull style grip to the top corner of the egress door window surround it allows the operator to treat the window like a giant soft drinks can with a technology they would recognise and be familiar with, even in a stressful situation. However, once designed they needed a partner who could cost effectively manufacture this to fine tolerances. So they turned to Birley to manufacture these safety critical items.
This design ensures that people, in a stressful situation and possibly low light conditions, did not have to worry about reading complicated instructions but would have a fast and intuitive solution at hand. This simple ring pull method, covered by a safety notice, to avoid accidental pulling or casual vandalism, allows the seal around the internal window to be pulled out so that the safety glass can then be safely pushed through leaving a clean, clear hole through which to exit.
The beauty of this design is that a safe exit can be created at whatever the final resting angle of the door and it is not dependent upon the door still being functional - a simple design but valuable and cost effective to manufacture too.
Birley worked closely with Unipart Rail on the design and testing of these units, prior to manufacture to ensure that the doors met with the relevant Railway Group Standards.
To date these doors have been fitted on First Great Western, Midland Mainline, Chiltern and One Rail fleets.
