Built circa 1896 for the Caledonian Railways Canal Department. Pentagonal basin with channel under swing bridge (listed separately) at W end and lock at E end. Elevated roadway and platform for house (listed separately) on N side.
BASIN: in form of irregular pentagon. Walls mass concrete, channelled as railway works, with ribbed copes.
CHANNEL: at W end, spanned by bascule bridge and swing bridge )both listed separately listed). Construction identical to that of basin, but under swing bridge walls taper down to level of cope of lower basin. On E side of bascule bridge standard Forth and Clyde Canal railings with cast-iron socket and wooden uprights, top and middle rail. Short section of similar rail under bridge on N side. Cast-iron bollards on each side at entrance to basin.
LOCK: chamber of similar construction to basin, gates recently replaced in steel. Cast-iron lamp standard in NE corner.
ELEVATED ROADWAY AND PLATFORM: along the N side, an elevated roadway, broadening at E end to accomodate houses (listed separately). To W of ramp, curved pink concrete wall with chamfered base and grey concrete cope, terminating in a squat circular pier. To E of ramp retaining wall, S curved at W end. Wall proper channelled as elsewhere, parapet marked at base by string course chamfered cope, pilasters at intervals with flat pyramidal caps. Cast-iron lamp standards at intervals with later steel tube swan-neck heads. Round House platform has stanchion and tube railing in place of parapet, and stair down to lock level at SE corner.