A fishplate, splice bar or joint bar is a metal connecting plate used to bolt the ends of two rails into a continuous track. The name is derived from fish,[1] a wooden reinforcement of a "built-up" ship's mast that helped round out its desired profile.[2] 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.[3]
In rail transport modelling, a fishplate is often a small copper or nickel silver plate that slips onto both rails to provide the functions of maintaining alignment and electrical continuity.
A flat plate, typically made of iron or wood, used esp. to connect two rails or beams together at a joint. Cf. fishplate n.2, fish bar n.2 Now historical and rare.