fog signal

English

Noun

fog signal (plural fog signals)

1. (rail transport, UK) A small explosive charge (detonator) which can be placed on a railway line in fog, to be detonated by a train passing over it as a warning signal to the driver.
   • 1943 November and December, T. Lovatt Williams, “Some Reminiscences of the Footplate—III”, in Railway Magazine, page 344:

     The layman does not realise the dreadful nightmare of running in fog, especially at night, when the safety of everyone depends on the driver hearing the fog signal detonate.

   • 1960 November, L. Hyland, “The Irish Scene”, in Trains Illustrated, page 691:

     The last train—a three-coach A.E.C. unit—from Belfast to Crumlin and back, was bade farewell with fog signals as it carried a capacity crowd of last-trip travellers.

References

• “fog signal”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.