This signal box controlled access to Holmes Pit No 4, a mine between Kilmarnock and Galston on the north side of the line served by a siding which ran north east from the box.
The box was on the south side of the line where the mineral siding made a trailing connection to the westbound line.
The box became a ground frame in 1933 and closed in 1938.
The main line remained open until 1964.