The holes in the fishplates are oval to allow expansion. The only job, until track circuiting came along, of the fishplates was to maintain rail alignment. In the UK the ideal gap between sections of panel track is 0.375in. When laying such track a small metal gauging shim is placed on the top of both rails of the track already in place. There is a video on YT showing how BR went about track replacement in the late 1950s/early 1960s.
Brilliant video
Thank you
The holes in the fishplates are oval to allow expansion. The only job, until track circuiting came along, of the fishplates was to maintain rail alignment.
In the UK the ideal gap between sections of panel track is 0.375in. When laying such track a small metal gauging shim is placed on the top of both rails of the track already in place. There is a video on YT showing how BR went about track replacement in the late 1950s/early 1960s.
Well, the hole in the rail needs to be broad enough to expand. Meaning the hole has to have a rectangle with semi circular ends.
Aldous Huxley quote