Former Guardhouse (now called the Post Office), Fort Blockhouse

Former Guardhouse (now called the Post Office), Fort Blockhouse

This single-storey building, dating to the early 19th century, incorporates the remains of a late 18th-century forge. It was converted to a post office and canteen in the 20th century. The structure is built of red stock brick and vitrified brick in Flemish bond beneath a slate roof.

The building is L-shaped in plan, comprising a rectangular main range with the former forge extending from its southern corner. A storage attic is accessed by taking-in doors set into the roof. The main entrance, positioned centrally on the north-west elevation, opens into a post room that also connects to a canteen and strong room. A separate external entrance to the left of the main entrance provides access to the strong room, behind which a passageway leads to the rear yard (now blocked). A doorway connects through to the former cells, originally two separate spaces but now opened into one. Two further entrances on the south-west elevation serve the canteen and former forge respectively, with a back door from the forge to the rear yard.

The principal north-west elevation comprises seven bays beneath a hipped roof. The three central bays are set back behind a round-arched brick colonnade carrying a post office sign. The central entrance features a four-panelled timber door beneath a three-pane transom light, flanked by sash windows of four-over-six panes in plain timber architraves on stone cills. The bays to the right of the colonnade contain sash windows with 20th-century segmental brick arches and stone cills; one retains four-over-six panes in a timber architrave with segmental head, while the other is a later replacement with three-over-four panes. The original windows to the left of the colonnade have been replaced with high-set, segmentally-headed hopper windows of six panes on heavy stone cills. A four-panelled timber door stands beneath the first bay. A rendered plinth runs around the building's base, and a tall chimney stack rises at the south-western end of the roof ridge.

The north-east elevation is largely blank except for a single high-set, segmentally-headed metal window of 21 panes beneath a brick segmental arch, standing on a heavy stone cill. Two rectangular ventilation grates with decorative patterns pierce the wall. The hipped end carries an inset central chimney stack.

The rear south-east elevation shows evidence of a former infilled doorway. Two windows similar to those on the north-east elevation are present: one high-set with horizontal louvres, the other low-set and surmounted by a louvered panel. At the northern end stands a rectangular decorative ventilation grate.

The south-west elevation comprises six bays. The first three form the guardhouse return, unified by matching stone cills and lintels. The first bay contains a six-pane glazed timber door with blocked transom light above; two sash windows with four-over-four panes stand to the east. Above the central bay a lucarne set into the hipped roof houses a sack hoist with taking-in doors. The remaining three bays form the later or rebuilt former forge section. A central planked entrance door is flanked by a three-over-two pane sash window to the left and a three-over-three pane example with reconstituted stone lintel to the right. The rebuilt forge chimney rises through the roof ridge where it is attached to an adjoining building to the south-east. The north-east elevation of the former forge mirrors this arrangement, though most lintels have been replaced with reconstituted stone.

Inside, the principal rooms feature high ceilings with dividing walls of either brick or timber boarding. Most timber internal doors are four-panelled, some retaining original iron handles and catches. The strong room contains a small wall safe (possibly relocated from a submarine or ship), functional shelving, and a blocked fireplace. The former cells feature a bricked-up fireplace and functional shelving, with one cell door infilled with timber. The canteen area has a blocked fireplace.

The roof structure of the former forge is partially exposed, displaying timber purlins and collars with four squared-timber beams tying the eastern and western walls together. At the southern end a substantial curved chimney breast rises to the ceiling. The connecting door to the former guardhouse is four-panelled with a simple architrave; either side stand two over-painted internal windows of two-over-three panes.