Spitbank Fort


Heritage Category:
Scheduled Monument
List Entry Number:
Date first listed:
Date of most recent amendment:


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The building or site itself may lie within the boundary of more than one authority.

City of Portsmouth (Unitary Authority)
Non Civil Parish
National Park:
National Grid Reference:
SZ 63634 97155

Reasons for Designation

The Royal Commission fortifications are a group of related sites established in response to the 1859 Royal Commission report on the defence of the United Kingdom. This had been set up following an invasion scare caused by the strengthening of the French Navy. These fortifications represented the largest maritime defence programme since the initiative of Henry VIII in 1539-40. The programme built upon the defensive works already begun at Plymouth and elsewhere and recommended the improvement of existing fortifications as well as the construction of new ones. There were eventually some 70 forts and batteries in England which were due wholly or in part to the Royal Commission. These constitute a well defined group with common design characteristics, armament and defensive provisions. Whether reused or not during the 20th century, they are the most visible core of Britain's coastal defence systems and are known colloquially as `Palmerston's follies'. All examples are considered of national importance.

Spitbank Fort is a well preserved example of its class. As part of an integrated sea based defensive line the massive structure of Spitbank also provides a visual reminder of the strategic importance of the Solent in the later 19th century.


The monument includes Spitbank Fort, a circular 19th century Royal Commission sea fort lying in the Solent on Spit Sand, 1100m south west of Southsea Castle. Spitbank Fort was one of a chain of four sea forts in the Solent recommended by the Royal Commission on the Defence of the United Kingdom in 1860, and designed to protect Portsmouth dockyard from seaborne attack. Construction started in March 1867 and the fort was completed by June 1878. The fort is circular in plan and includes sea bed foundation walls of 8 ton pre-cast concrete blocks with an inner and outer casing of masonry. At the sea bed the structure is 49.4m in overall diameter and the thickness of the walls is 14.6m. The area enclosed by the circular walls is filled with shingle capped with a slab of concrete 3m thick. Above this lies a basement divided radially into compartments for ammunition and stores. The ammunition stores were equipped with lifts to raise shells and cartridges to the guns on the floor above. Above the basement the main floor supported the guns, for which there are fifteen positions, six in granite fronted brick casemates on the northern (landward) side of the fort and nine within an iron armoured gun gallery facing out to sea. Within the centre of the fort, behind the casemates and gun gallery, are the accommodation and ablutions for soldiers, sergeants and officers. Above this floor, the roof, which is reached by means of an iron staircase, supports the battery observation post and lighthouse, the loading gantry, and gun emplacements and other structures dating from the late 19th and early 20th centuries. The small building which is all that remains of the soldiers' latrine is cantilevered out from the exterior of the fort. The fort was armed with nine 12.5 inch 38 ton Rifled Muzzle Loader (RML) guns on its armoured side and with 7 inch 7 ton RML guns facing landward. Most of the RML guns were removed by 1898 when 4.7 inch Quick Firing (QF) guns were mounted on the roof. The fort was armed during both World Wars, the last gun being removed in 1948. All modern security fittings, lighting, safety and catering equipment, signs and all replica guns and introduced fittings and the replacement landing stage are excluded from the scheduling, although the structures beneath are included.

MAP EXTRACT The site of the monument is shown on the attached map extract.


The contents of this record have been generated from a legacy data system.

Legacy System number:
Legacy System:


Books and journals
Mitchell, G, 'Solent Papers no. 1' in Spit Bank And The Spithead Forts, (1986)


This monument is scheduled under the Ancient Monuments and Archaeological Areas Act 1979 as amended as it appears to the Secretary of State to be of national importance. This entry is a copy, the original is held by the Department for Digital, Culture, Media and Sport.

End of official listing

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