Caused by one steam train being filled up with ale rather than water. Think it was Thomas the Tanked-Up engine.
This train of thought needs flagging up Foot note to the incident it was rumoured that a young man from Sheffield came to the rescue of a damsel in distress ...apparently the lady in question had been covered in the corrosive liquid which in turn had seen her clothes disintegrate ....whilst she stood there naked he wipped of both his shirt and trousers and shouted don't worry folks diesel fitter...