S K Sharma, Retired Addl General Manager, Southern Railway.
The bullet trains are generally classified as high speed trains having speed of 300 kmph (Kilometers per hour). These trains are currently running in many countries including China, France, Germany, Italy, Japan and so on to connect major cities. The commercial speeds of the Bullet Trains are hovering between 300 – 430 kmph in a typical track vehicle interaction mode. The track gauge is generally standard gauge (1,435 mm) in Japan and European countries resulting in that most of the high speed technologies have been developed on standard gauge viz track, coaches, engines, signalling, telecommunications, and electrical systems.
At this high speed, the track vehicle interaction becomes highly sensitive to even minute obstructions like a small pebble or a small iron piece which may cause major catastrophe. In India, major obstructions on the track are quite common. Even under ordinary passenger trains, people place coins to convert it into 8 annas coins playfully. Or they simply put nails in track joints to see what happens. Not only village illiterate but also urban literate people find the track as most convenient place for morning chore where even politics is discussed in addition to relieving themselves. The crossing of track takes place not only on level crossings but also on plain track which leaves any high speed operation to a horrendous imagination in case of any catastrophe.
Both sides of the railway track in India are gradullay developed as grasslands where cattle have become habitual in track crossings. In such circumstances any high speed operation even beyond 140 kmph becomes a big question mark leaving alone the bullet train operations. For solving this problem, various suggestions are made. The continuous fencing becomes too prohibitive and chances of fence breakage are fairly quite common. The avoidance of all level crossings by Road over bridges or Road under bridges may not prove to be a solution since it may not provide a guarantee that neither people on both sides will cross the track nor cattle will graze the track.
To run a high speed train on mixed traffic route (where goods and passenger trains operate on the same track) is not technically possible since the track design, track degradation, and maintenance practices are quite different for slow moving high axle load goods trains, and high speed low axle load passenger trains. Therefore, to sum up for high speed bullet train operations, a new dedicated overhead elevated alignment over columns along with Cab signalling becomes a must. Under this arrangements, large scale land acquisition problem shall also be addressed. Some quarters oppose the construction of High speed train structures on viaducts (Elevated) since it is unsafe. California High speed track was constructed on ground with an added advantage of lesser cost. Japan has been operating High speed train on elevated tracks for over 40 years without a single mishap. In India, the probability of an accident on elevated structure is one in million then with surface track the probability of an accident is quite high in High speed operations due to various reasons as mentioned earlier.