This signal box was on the north side of the Muir Street overbridge, which crossed the Motherwell Deviation Line (Caledonian Railway) on an oblique a little to the north of Lesmahagow Junction.
The box was on the west side of the main running lines, with the line approaching Motherwell Shed from the south on its west side. The southern coal stage was just to the north with a turntable off to the west. On the east side were the Parkneuk Works, with a southern approach
The box closed in 1948 but the lines and shed survived it.