Indian Railways consider their Schedule of Dimensions (IR-SoD-2004) as sacrosanct. They do not deviate, so it is said, from the prescribed dimensions. If any deviation is to be made, they have to approach their Research Design Standards Organisation at Lucknow (RDSO). As per IR-SoD-2004, the floor of the new rakes are to be at 1,200 mm from Top of Rail (ToR) and the Platform level at the coping (edge) between 760 mm to 840 mm. For the older rakes, the floor levels vary from 1,345 mm at empty condition and 1,200 mm at fully loaded condition.
The older rakes have coil springs as suspension while the newer rakes have pneumatic suspension, as they have in Metro rail coaches. Pneumatic suspension compresses additional air into the air cylinder to take up extra load and maintain the coach floor level constant. Thus, the ‘official’ vertical gap from the platform for new rakes would vary from 360 mm to 440 mm. For the old rake, this would be between 360 mm and 585 mm.
At many places, the vertical gaps are as little as 150 mm. Such deviations have come about because the Divisional Railways have been working to try out ideas that would reduce the high vertical gaps that would arise if the IR-SoD-2004 is fully adhered to. Currently railways are looking at the possibility of raising platform level further to 920 mm by condoning the standards, thus the maximum vertical gap could come down to 280 mm for new rakes and to 425 for empty old rakes.
Still this is unacceptable gap. The minimum gap in this case works out to 280 mm for new and old rakes. The reality is that the minimum vertical gap is about 150 mm at several platforms. The reason for providing the minimum gap of 280 mm is to cater to the eventuality when the air in the pneumatic cylinder leaks and the coach fully sinks to the minimum level and liable to strike the platform coping.
However, there is a solution that would provide level boarding and alighting by raising the platform level to 1,200 mm for the new coaches and old coaches respectively. This will give 50 mm horizontal gap (could be safely reduced to 35 mm after testing since in Metro rail, it is 25 mm).
This solution has a drawback in case of platform with sharp curve, the horizontal gap for the middle two doors of the coach will be more than considered 50 mm. In such case exceptional scheme of non-level boarding or alighting could be adopted. Level boarding and alighting will help persons with disability.
Writer is a member of the Bombay High Court committee for making the railways friendly towards persons with disability.