A fishplate joins two lengths of track A fishplate, splice bar or joint bar is a metal connecting plate used to bolt the ends of two rails into a continuous

track Track or Tracks may refer to: Routes or imprints * Ancient trackway, any track or trail whose origin is lost in antiquity * Animal track, imprints left on surfaces that an animal walks across * Desire path, a line worn by people taking the shorte ...

. The name is derived from ''fish'', a wooden reinforcement of a "built-up" ship's mast that helped round out its desired profile. The top and bottom faces taper inwards along their short dimensions to create an even alignment between the two rails when the fish plate is wedged into place by tightening its bolts during installation. In

rail transport modelling Railway modelling (UK, Australia, New Zealand, and Ireland) or model railroading (US and Canada) is a hobby in which rail transport systems are modelled at a reduced Scale (ratio), scale. The scale models include locomotives, rolling stock, ...

, a fishplate is often a small

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

or nickel silver plate that slips onto both rails to provide the functions of maintaining alignment and electrical continuity.

History

The device was invented by William Bridges Adams in May 1842, because of his dissatisfaction with the

scarf joint A scarf joint (also known as a scarph joint) is a method of joining two members end to end in woodworking or metalworking. The scarf joint is used when the material being joined is not available in the length required. It is an alternative to ...

s and other systems of joining rails then in use. He noted that to form the scarf joint the rail was halved in thickness at its ends, where the stress was greatest. It was first deployed on the

Eastern Counties Railway The Eastern Counties Railway (ECR) was an English Rail transport, railway company incorporated in 1836 intended to link London with Ipswich via Colchester, and then extend to Norwich and Great Yarmouth, Yarmouth. Construction began in 1837 on t ...

in 1844, but only as a wedge between the adjoining rails. Adams and Robert Richardson patented the invention in 1847, but in 1849 James Samuel, the engineer of the ECR, developed fishplates that could be bolted to the rails.

In rail switches

The moving blades of a railroad switch can be connected to the closure rails by looser than normal fishplates. This is called a heeled switch. Alternatively, the blade and closure rail can be a one piece heel-less switch, with a flexible thinned section to create the moving heel.

Electrical bonding

When railway lines are equipped with

track circuit A track circuit is an electrical device used to prove the absence of a train on rail tracks to signallers and control relevant signals. An alternative to track circuits are axle counters. Principles and operation The basic principle behind t ...

s, or where the line is electrified for electric traction, the electrical connection provided by fishplates is poor and unreliable and has to be supplemented by bonding wire spanning the joined rails fixed by spot welding or other means.

Welded joints

An improvement over fishplate rail connectors is directly bonding rails together using thermite welding. In 1967, the Hither Green rail crash occurred on the Southern Region of

British Railways British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most of the overground rail transport in Great Britain from 1948 to 1997. It was formed from the nationalisation of the Big Four British rai ...

when a rail fractured at its fishplate joint. The crash accelerated welded rail connections, with strict procedures on concrete and wooden

sleepers ''Sleepers'' is a 1996 American legal crime drama film written, produced, and directed by Barry Levinson, and based on Lorenzo Carcaterra's 1995 book of the same name. The film stars Kevin Bacon, Jason Patric, Brad Pitt, Robert De Niro, Dustin Ho ...

References

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External links