This signal box was south east of Merryton Junction on the Lesmahagow Railway. It controlled access to Bog Colliery Pits Nos 1, 2 and 3, to the east, and Dykehead Colliery to the south.
The box was on the south/west side of the line. Both collieries were approached from the north. Dykehead (alternatively Dikehead) was an old colliery which predated the signal box.
The line was single track, then doubled. The box closed in 1940. The line reverted to single track in 1949.
The site is now overgrown next to the West of Scotland Cart Club .