Fishplates are used to join rails. FR uses 4-hole fishplates.
The holes in the rail may be predrilled when made, or they may be drilled on site. QNNA: A special jig called a _________ is used to drilled the holes, in the "neutral axis" of the rail.
Four hole fishplates give a more rigid joint than two hole ones. On the FR doublehead rail patent Spooner Huddart fishplates were common. The bottom of the plates were extended to clamp right around the foot of the rail. The inventors were George Augustus Huddart and Charles Spooner. See the three pictures at the bottom of this page. This style of fishplates were commonly called clip plates and were widely used on UK standard gauge railways in the nineteenth century. (Dow 2014)
Most fishplates on the FR were four holed - but not all. When the FR revival began there were some 2 hole fishplates. Fred Howes reports as follows (Howes, 2016):
"When I first came to the FR there were 2 hole fishplates in several places, Penrhyn and Gwyndy Bank were the two I recall the most. According to Will Jones there was a PW Engineer from the LMS involved at some time, apparently the 2 hole plate was widely used there but when used on FR the plates were shorter and when the sleepers were placed so their chairs were close to the fishplates the inner sides of the 2 joint sleepers were virtually touching so it was impossible to pack them properly. Consequently the sleepers split down the middle, the joint sank and stressed the fishplate bolts which came loose, indeed on some joints in Penrhyn it was not unusual to find them lying on what then passed as ballast!
"I recall rebuilding the joints down Gwyndy Bank by replacing both sleepers and fitting 4 hole fishplates. As the track then was lower with the coping stones almost level with the rail top this required a lot of digging!"
According to Boyd the 2 bolt fishplates were introduced in the late 1930s. (Boyd 1975) There were more of these 2 holes plates on the sections of pre revival FR track lifted between Tan y Bwlch and Dduallt and Tanygrisiau and Glan y Pwll between 1966 and 1975. The Volunteers' Manual published in 1965 says "it is now customary to replace two-hole fishplates with the four-bolt type."
The size and shape of fishplates depends on the Rail Types and weight. The fishplates on FR flatbottom rail from whatever source have all been four hole plates. They often have hexagonal nuts whereas the nuts on chaired track (doublehead and bullhead) were usually square. This has a big effect on how easy it is to get a spanner onto the nut to loosen or tighten it - hexagonal nuts being much easier than square ones.
Special custom-made fishplates are needed to join rails of different types and/or weights. More usually welded closure rails are used to avoid the need to do this.
(QNNA) Fishplates are made of steel. When it is too mild there can be problems with fishplates bending. One such batch was supplied for use with bullhead rail in around 1970 and gave problems. When rails were of wrought iron, fishplates will have been of the same material.
Boyd J.I.C. (1975) The Festiniog Railway page 374, Oakworth Press, Old School House, Tarrant Hinton, Blandford, Dorset, UK.
Dow A (2014) The Railway: British track since 1804 page 161, Pen & Sword, 47 Church Street, Barnsley, South Yorkshire, S70 2AS, UK.
Howes F (2016) Email to MT on 12/4/2016.