 A laboratory is built into the rear wall , on the forts southern side . This room is set into the end of the rampart and was used to prepare gunpowder charges . A <unk> was built at the manning parade 's southern end in 1885 . It is now used as a duty room for the drill squad during recreation demonstrations but originally was a guard 's room and separate cells connected by telephone to Fort Largs . Up to three men appear to have been accommodated in the guard 's room . When the fort was converted to use as a caravan park the guard house was converted to an ablution block . A store and ablution block were also built in 1885 between the stockade and rear defence wall . 
