Cannon Bollard, Fort Blockhouse

Overview

Heritage Category:
Listed Building
Grade:
II
List Entry Number:
1469577
Date first listed:
13-Nov-2020
Statutory Address:
Fort Blockhouse, Haslar Road, Gosport, PO12 2AB

Map

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Location

Statutory Address:
Fort Blockhouse, Haslar Road, Gosport, PO12 2AB

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

County:
Hampshire
District:
Gosport (District Authority)
Parish:
Non Civil Parish
National Grid Reference:
SZ6249199109

Summary

Cannon, probably cast in the early C19, now upended to form a bollard near the entrance to Fort Blockhouse.

Reasons for Designation

The cannon, probably cast in the early C19, now upended to form a bollard near the entrance to Fort Blockhouse, is listed at Grade II for the following principal reasons:   Architectural interest:   *     as a representative example of an early C19 cannon, reused as a bollard at the former boundary of the early C18 artillery fort.   Historic interest:   *     for its historic association with Fort Blockhouse, a bastioned artillery fort that was central to the defence of Portsmouth Harbour in the C18 and C19, subsequently becoming a Royal Engineers establishment in the late C19, before serving as a principal base and spiritual home of Britain’s submarine service during the C20.   Group value:   *    with the scheduled artillery fort of Fort Blockhouse. The group value extends to further listed buildings and structures, including the gatehouse datestone (C18), Admiralty boundary stone (C18), the former guardhouse (C19), Arrogant and Thames Block (C19), the Submarine Memorial Chapel (built 1917), the submariners’ memorial (C20), and the Submarine Escape Training Tower (C20).

History

Fort Blockhouse is sited on the western side of the entrance to Portsmouth Harbour at the end of a peninsula joined to Haslar by a narrow neck of land. A timber blockhouse was recorded on the site in the early C15. It stood opposite The Round Tower (NHLE 1386901) on the eastern side of the harbour entrance; a chain between the two securing the entrance against enemy ships. In about 1538 the west side was refortified with the addition of Lymden’s Bulwark but by the late C16 the fortifications were derelict. In the late C17, during the Second Dutch War (1672-1678), concerns over the vulnerability of naval dockyards to attack led to new schemes by the great fortress engineer Sir Bernard de Gomme to strengthen Portsmouth’s defences. An L-shaped battery was built on the site. A plan of 1668 shows a fort with defences facing the land and sea. In about 1709, there was major reconstruction work. The fort’s south-west defences were considerably strengthened with a redan, moat and outer work, as well as a south-east sea battery. The remaining north-west and north-east sides of the fort were enclosed by oak palisades with an angled bastion to the north. In the early C19 further work was undertaken, including the northwards extension of the western face of the west demi-bastion and extensive remodelling of the sea battery. Between 1845 and 1848, the sea battery was further strengthened and new casemates were built on the north and the eastern sides of the fort, as well as a limestone-faced north bastion. However, the advent of larger rifled cannon meant the defences became increasingly obsolescent as the C19 wore on.

In 1873 Fort Blockhouse was taken over by the Royal Engineers who were engaged in the use of fixed minefields as a means of harbour defence. A loading shed, workshops, mess room, boat and cable sheds, and a jetty were built. In 1904, the fort became a submarine base with the addition of new jetties and submariners accommodation. The hulk HMS Dolphin was also brought to the site to provide further accommodation and in 1912 gave its name to the newly established independent command. During the First World War, the base was the Royal Navy’s principal submarine depot and a memorial chapel was erected in 1917. A mock submarine control room known as an ‘attack teacher', was also erected along the northern curtain wall; only traces in the brickwork now remain. After the war, the outer C18 defence works were reduced, the moat partly infilled, and several buildings constructed within the fort interior, outside the main gate and surrounding it. In 1935 to 1937, a new headquarters was built for Rear Admiral, Submarines (commander of the service) with an operations room and communications facilities. At the outbreak of the Second World War, HMS Dolphin was home to 5th Submarine Flotilla. Operations were conducted in the Channel and the Bay of Biscay, and in June 1944 X-craft from HMS Dolphin were used to mark the D-Day landing beaches. After the conflict HMS Dolphin resumed its role as the main base for the submarine service, rising in prominence in the mid-1960s when the service provided the country’s nuclear deterrent. The base expanded with many new buildings on the land to the south-west of the peninsula. However, the end of the Cold War in 1991 led to a major reappraisal of defence requirements, and HMS Dolphin closed in 1998. The Submarine School was transferred to HMS Raleigh at Torpoint, Cornwall, and the Defence Medical College was established at Fort Blockhouse; the base being occupied by 33 Field Hospital. In 2016 the government confirmed that Fort Blockhouse was to close; the estimated date for disposal is 2022.

The cannon bollard at Fort Blockhouse is located adjacent to the Admiralty boundary stone of 1774 on the seafront at the neck of the peninsula which leads to the fort. It is situated beyond the location of the redan and outer works which originally stood in front of the fort entrance. It is probably of Napoleonic origin from the early C19 and pre-dates the introduction of rifling (casting of spiralling lines inside the barrel) for artillery, which was patented in 1855 to improve accuracy through gyroscopic stability. Older smoothbore cannon subsequently became obsolescent and other uses would have been sought for them, many being used as bollards. The detail of the cannon casting at Fort Blockhouse is somewhat denuded but its functional mouldings are still evident. It is currently (2020) painted black.

Details

Cannon, probably cast in the early C19, now upended to form a bollard near the entrance to Fort Blockhouse.

DESCRIPTION: the cannon is orientated barrel-up with the breech set into a concrete pavement so that only around half the length of the cannon is visible and the trunnions (the pair of pivots on the side of the barrel) cannot be seen. It has a tapering barrel with the muzzle mouldings, astragal and second reinforce ring visible. The barrel flares out at the mouth in a muzzle swell and the bore is fitted with a stopper.

Sources

Books and journals
Evans, D, Arming the Fleet: The Development of the Royal Ordnance Yards, (1770-1945)
Hall, K, HMS Dolphin: Gosport's Submarine Base, (2001)
Williams, G H, 'The Western Defences of Portsmouth Harbour 1400-1800' in The Portsmouth Papers , , Vol. 30, (1979), Unknown
Other
Francis, P, and Crisp, G, Military Command and Control Organisation, report for English Heritage (2008)
Historic England, Screening for Potential Listing Report: Fort Blockhouse, Gosport, Hampshire (2020)

Legal

This building is listed under the Planning (Listed Buildings and Conservation Areas) Act 1990 as amended for its special architectural or historic interest.

End of official listing

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