Detonator (railway)
![This illustration from an 1882 Leslie's Monthly portrays an engineer (fireman) finding a torpedo on the track.](/Images/godic/202502/06/Railroad_torpedo3508.jpg")
![A torpedo on a rail](/Images/godic/202502/06/Railroad_torpedo_with_lead_straps3508.jpg")
![A detonator on a railway line in Belgium](/Images/godic/202502/06/Pétard_sncb3508.jpg")
A railway detonator (torpedo in North America) is a coin-sized device that is used to make a loud sound as a warning signal to train drivers. It is placed on the top of the rail, usually secured with two lead straps, one on each side. When the wheel of the train passes over, it explodes emitting a loud bang. It was invented in 1841 by English inventor Edward Alfred Cowper.