The ground floor has a moulded segmental pend arch; the first floor a triple window; and the second floor an armorial panel featuring the Carron Company seal. The tower is topped by a square clock turret and a pyramid spire.

On either side of the pend, set into the front walls, are a furnace lintel from 1760 and a date plate from a boiler connected with James Watt. The pend is fronted by a wrought iron screen and contains two carronades and two 9-pounder long guns set on garrison carriages.