What are these ‘clips’ for on the side of Underground trains? This is from the Circle line’s S7 stock

3 comments

1. Try opening it and see

2. Manual release.

   Only used in an emergency or when the train is undergoing maintenance.

3. Before the invention of the electric motor, trains were pulled by horses, mules, or ponies along the rails – this is the clip to which the animal was attached. This is also why you often see a towpath by a train track, although most are defunct these days.