You must have come across diesel train engines being left in running condition. In fact, they are always left in a running state while waiting for signal.
But, ever wondered why the railway department prefers not to switch the engine off even if the train is stopped, thereby wasting so much fuel.
A train engine requires about a hundred litres of fuel to get it started. So it wouldn’t be economical if the engine is stopped and started frequently.
This apart, if the engine is stopped, the moving parts’ lubrication will also come to a halt. When the loco pilot is green-signalled to start the engine, it takes him some time for full lubrication.
Another reason is if the engine is switched off for a long period of time, the loco pilot can’t start it as soon as he gets green signal and asked to leave the platform.
A train engine takes a lot of time to again build up the optimal break line pressure for efficient breaking in the journey. If a train remains on tracks even after getting green signal, it may result in accidents.
Besides this, if the engine is started after a long shutdown, the loco pilot takes 10 to 15 minutes to prepare a proper checklist to restart the engine.
10 to 15 minutes on tracks even after green signal would mean disastrous when train traffic is concerned.
Let’s understand another reason why the engine is kept in a running state. The engine has usually 16 big size cylinders. So if the loco pilot switches off the engine, then the engine takes time to get restarted. It starts only when it achieves ignition temperature.
At the same time, along with the engine, several other components are also in the running state . If the engine is turned off, the possibility of technical problems is high.
These are the reasons why the train engine is left in running state even when the train is at the platform.