Tregantle Fort

Tregantle Fort

Fort, built in 1865. Constructed of snecked rockfaced limestone rubble with stone dressings.

The fort has an irregular six-sided plan with a gatehouse to the south east, a keep to the east, barrack blocks along the south, and three caponiers facing west. It was designed to mount smooth bore breech-loading 32-pounder guns as its principal armament.

The gatehouse features a round-arched entrance with rockfaced banded rustication, a keystone, and a lantern overthrow bearing the inscription TREGANTLE FORT. The entrance is formed by double panelled studded doors. A bull nose moulding stepped up over the parapet above the archway is interrupted by two blind recessed shields. Inside the gatehouse, quadripartite brick vaulting contains doors to vaulted chambers on both right and left. The inner archway is plain and round-headed in granite, with a circular stone sentry-box to the right featuring a round-arched opening and squint lancets to each side. An Edward VII letter box is set into the wall to the left.

To the left of the gatehouse, seven bays with round arches in stonework each span a segmental-headed gun casement with lancets to each side and a horizontal opening above. The bull nose moulding continues over a brick parapet with seven stacks heating the barrack blocks. A two-storey ravelin at the left end has two gun casements to the side at ground and first floor level, and one to the front.

To the right of the gatehouse, the outer side of the keep has walls ramped up to right and left, with eight similar round arches in stonework and similar openings. At upper level there are five segmental-headed gun casements. Walls to the right are built up with earthworks.

Inside the fort, the south east range contains six bays of barrack blocks with round arches recessed over doors flanked by 12-pane sashes. Along the southern range, the blocks are splayed: a three-bay range with round arches features 24-pane sashes at first floor and doors with 12-pane sashes at ground floor (some blocked); the main barrack range of eight bays has round arches each over three sashes at first floor with cill and upper band courses and a central rectangular opening above the sashes. The ground floor has a central door with overlight and a sash to each side in each bay, with a parapet, coping, and stack to each bay. Two windows without arches and a door at each end complete this range. The range splays back at the right end with one and four similar bays before the parapet steps down to a lower one and a half storey range with three and six bays of round arches, doors, and sashes, leading up to the south west caponier.

The keep, fronting the east side, is semi-circular in plan facing inwards, with two storeys. It features round arches each spanning triplet openings—large to the centre with lancets to each side and a horizontal opening above. Bull nose moulding runs above, with 12 bays above each featuring a central casement with segmental head and keystone. The third bay from the east contains a segmental-headed doorway with stepped head and granite voussoirs and keystone. Sockets remain for a drawbridge over the ditch, now replaced with a fixed bridge. Railings run along the ditch parapet wall.

Inside the fort, road intersections are marked by piers on chamfered plinths with flat tops and carved raised crests of regiments. To the north west, two circular gun emplacements have brick vaulted roofs with shackles to the sides and metal circular gun pivot tracks. The parapet steps up over these. Three raised caponiers defend the west side.

Historical context: Following an 1859 commission established by Palmerston to consider the defences of the United Kingdom—prompted by public concern over French construction of iron-clad warships—the design of the forts fell to the Royal Engineers under Colonel, later Lieutenant General, Sir W.F. Drummond Jarvis. Tregantle Fort formed part of the outer line of defences protecting Plymouth. The estimated cost was £189,999, though the final cost on completion in 1865 was £189,119. The fort was designed for 35 guns, with 12 to bear upon the front, excluding lighter guns for ditch defence. Situated approximately 360 feet above sea level with ditches on the east, north, and west sides and reverted scarps and counterscarps flanked by the western caponiers, Tregantle commanded an extensive view. The total number of guns installed at Tregantle was 87. In 1866, the Coast Brigade RA quartered a regular element at the fort. By 1882 it was manned by the Garrison Artillery Coast Bridge with only six other ranks. From 1900 to 1903, an Infantry Battalion was headquartered there with 14 officers and 423 other ranks. From 1903, the ranges were used for musketry training.