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 ...

nickel silver Nickel silver, Maillechort, German silver, Argentan, new silver, nickel brass, albata, alpacca, is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver does not contain the eleme ...

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 William Bridges Adams (1797 – 23 July 1872) was an English author, inventor and locomotive engineer. He is best known for his patented Adams axle – a successful radial axle design in use on railways in Britain until the end of steam tracti ...

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 James Samuel (21 March 1824 – 25 May 1874) was a railway engineer who was born in Glasgow on 21 March 1824. He was appointed engineer to the Eastern Counties Railway in 1846. He held two important patents but, in both cases, the invention was ...

, the engineer of the ECR, developed fishplates that could be bolted to the rails.

In rail switches

The moving blades of a

railroad switch A railroad switch (), turnout, or ''set ofpoints () is a mechanical installation enabling railway trains to be guided from one track to another, such as at a railway junction or where a spur or siding branches off. The most common ty ...

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 A railway electrification system supplies electric power to railway trains and trams without an on-board prime mover or local fuel supply. Electric railways use either electric locomotives (hauling passengers or freight in separate cars), ele ...

, 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 Exothermic welding, also known as exothermic bonding, thermite welding (TW), and thermit welding, is a welding process that employs molten metal to permanently join the conductors. The process employs an exothermic reaction of a thermite composit ...

. In 1967, the

Hither Green rail crash On 5 November 1967, a busy Sunday evening train service from to derailed near the Hither Green maintenance depot in London, between and railway stations. Of the twelve coaches, many full of standing passengers, eleven were derailed and four ...

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 H ...

References

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External links