Annett's key

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Groundframe, with the two rightmost levers locked by Annett's key

In British, Australian, French, and Swiss railway signalling, an Annett's key is a form of trapped-key interlocking that locks levers or other items of signalling apparatus, thereby serving as a portable form of interlocking.[1][2] When not in use, the key is normally held in an Annett's lock that is fixed to the lever or concerned apparatus.[1]

History[]

The Annett's key takes its name from its inventor, J. E. Annett of the London, Brighton and South Coast Railway. Annett patented his design in 1875; in 1881 that patent was bought out by Saxby and Farmer.[3]

See also[]

References[]

  1. ^ Jump up to: a b "Network Safeworking Rules and Procedures: Annett's Keys" (PDF). ArcInfra.com. Brookfield Rail. 31 March 2016. p. 6. Retrieved 31 August 2021.
  2. ^ Wägli, Hans G. (2018). Hebel, Riegel und Signale [Levers, Bolts and Signals] (in Swiss German). Diplory Verlag. pp. 159, 176. ISBN 9783033064102.
  3. ^ Foster, Richard D. (1982). A Pictorial Record of L.N.W.R. Signalling. Oxford Publishing Co. p. 166. ISBN 9780860931478.
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