How a Rat derailed the train at Shahdara ?

 One mishap to the Frontier Mail deserves mention if only for the unusual circumstances in which this crack train was derailed. In truth it was a RAT that caused a top-link driver to over-run signals at Shahdara Junction., the first stop on the way from Lahore to Lalamusa. 

The engine, SP/S class 4-4-0, had picked up two compos and backed them down on to the train at Lahore. All coupled up, the driver had 'created vacuum' and the guard, carrying out instructions, had duly tested the brakes by partially destroying the vacuum. With everything apparently in proper working order, the train had gone on its way.

But at Shahdara, the driver after shutting off steam found to his amazement that he had hardly any brake power and did not even have time to reverse his engine and apply steam again before the train overshot the starter which was at danger, and the leading bogey-wheels of the engine ran off the rails at the end of a short catch spur to which the points had been correctly set.

No one was injured but it was some time  the cause of the mishap was revealed. In the chill of the night, a RAT had sought the comparative warmth of the hogger pipe on the leading coach which, contrary to standing orders, some wayward shunter had not placed on the dummy. When the driver picked up the coach the RAT had no doubt been very much alive, and when the guard had tested the vacuum the air had by-passed the animal quite readily. 

But ten minutes of 20 to 22 inches of vacuum on the run to Shahdara had killed the RAT with the result that when the driver destroyed the vacuum to apply the brakes the corpse was SUCKED along the pipe until it jammed at a right-angled bend and effectively prevented the air from getting past.

P.S.A BERRIDGE