Summary
The standing remains, earthworks and buried remains of a polygonal artillery fort built in 1858 to 1862.
Reasons for Designation
Fort Grange, built in 1858 to 1862 as part of the Gosport Advanced Line, is scheduled for the following principal reasons:
*Â Â Survival: as a polygonal fort of The Gosport Advanced Line and immediate predecessor to the massive programme of defensive works stemming from the 1860 Royal Commission and prompted by the same fears of a French invasion. Fort Grange forms an important part of the defences of Portsmouth, the oldest, most extensive and best surviving group of dockyard defences in the country; whilst the earth covering to the fort casemates has largely been removed, the fort buildings survive well, retaining a good number of details internally;
*Â Â Diversity: as a good surviving example of a âpolygonalâ fort predating the 1860 Royal Commission and built in a classic Prussian form with a âkeep of last resortâ at the zenith of these polygonal designs; Fort Grange is important for the high diversity of its surviving features: including the keep, caponiers, casemates, magazines, gun ramps, and the moat (as an earthwork and buried feature);
*Â Â Documentation: the site is well documented in historical terms, including written accounts, historic plans, maps and photographs;
*Â Â Group value: as one of four surviving designated forts of the Gosport Advanced Line, which together represent a coherent and distinctive group of sites within the overall scheme of mid-19th century coastal defence. More widely, also with the many other designated artillery fortifications associated with Portsmouth Harbour, such as the Gosport Lines, Fort Monckton and Fort Gilkicker; together serving as an impressive ensemble that well illustrates the defence of this strategic harbour over a long period of time.
History
Artillery forts are generally seen as the successor to the medieval castle in the era of gunpowder artillery. They are typically self-defensible, permanent works intended to be regularly garrisoned and, in this form, broadly date from the C15 to the late C19, although their construction usually corresponded with periods of invasion threat (Saunders 1998, 1). An artillery fort was generally enclosed on all sides by a wet or dry ditch/moat, and a rampart/curtain wall with a parapet. Over time, forts employed varying geometrical figures, such as a square, star or pentagon, and some were fortified with bastions and/or demi-bastions or without bastions but possessing other forms of close defence. In about the late C18, engineers experimented with alternatives to the limitations of the bastion system, such as using caponiers (covered gun positions extending into the fort ditch) for close defence. There was thus a gradual process of design change from the classic âbastionedâ fort of the late C17 to the âpolygonalâ fort of the mid-C19 with a transitional phase (âtransitionalâ forts) in between (Ibid, 5). In the Gosport Advanced Line there were prototypes of a polygonal fort to the north and south (Forts Elson and Gomer) with the space between filled several years later by the more developed Forts Brockhurst, Grange and Rowner (see below). These last three preceded and anticipated the land forts advocated by the Royal Commission on the Defence of the United Kingdom report of 1860 (Royal Commission forts or Palmerston Forts, also colloquially known as âPalmerstonâs Folliesâ).
The following history is a summary largely based on a detailed study by Moore (2019, 1-46). There had been several earlier phases of fortification built around Gosport and Portsmouth Harbour but the Crimean War of 1854 to 1856 again set defence building in motion. The war had shown that a well-armed and well-manned fort at Sebastopol was able to withstand a fleet of ships. Furthermore, after the war, Napoleon the Third, nephew of Bonaparte, was considered to be a threat to Britain, whilst the French Navy was seen to be challenging the Royal Navy for supremacy at sea. A comprehensive plan for redesigning the Gosport and Portsmouth Harbour defences was drawn up by Colonel W F D Jervois from 1856. It consisted of an interlocking system of fortifications surrounding Portsmouth Harbour; effectively creating a âRing Fortressâ. Existing fortifications were considered to be too small to be effective and had their fields of fire obscured by the outward growth of the urban areas. Gosport was to be strengthened with new batteries at Stokes Bay and three new forts, known as Forts Brockhurst, Grange and Rowner, built in 1858 to 1862 between Forts Gomer and Elson to form the âGosport Advanced Lineâ. Jervois gathered the foremost military engineers and appointed Captain William Crossman to plan the three new forts to matching designs and also re-construct the Hilsea Lines. He had been involved in planning the Great Exhibition of 1851 and later went on to design the forts on Portsdown Hill and become the MP for Portsmouth. Whilst the above was in motion, a Royal Commission was set up under the direction of Lord Palmerston on 20 August 1859 to consider the wider defences of the United Kingdom. The existing plans to defend Portsmouth Harbour continued, with some modifications, and Portsmouth was fortified on a scale never before seen in England. The forts eventually became known colloquially as âPalmerstonâs Folliesâ.
The Gosport Advanced Line was built with polygonal forts; each with a trace based on an irregular polygon, a practice first adopted on the continent. They were designed to secure the western approaches to Portsmouth Harbour and constructed based on the âPrussian Systemâ; each fort being independent but also acting as part of a defensive line affording interlocking fields of fire whereby the guns in the flanks covered the approaches to the main ramparts of the adjacent forts. Forts Brockhurst, Grange and Rowner were the first stage in the evolution of this form of fort in England. They adopted a plan form of a detached bastion with an obtuse salient. The bastion was excavated from the level and the spoil used to create the ramparts and redan of each fort. The ramparts at the north, south and west consisted of casemated barrack rooms covered with earth, on top of which were the gun positions (mounted in Haxo casemates at the flanks). Placed centrally to the rear of each fort was a circular âkeep of last resortâ designed with an inner and outer half that could stand as a separate structure if either were captured. The main rampart was at the west (the expected direction of any attack) which was armed with guns for long range defence. In front of it was a V-shaped rampart known as a redan, beyond which was a gently sloping defensive earthwork known as a glacis which prevented direct fire from an enemiesâ breaching batteries. The guns in the flanks provided shorter crossfire in the space between the forts, whilst caponiers (bomb proof buildings projecting out into the ditches) were provided to contribute to the local defence of each fort. The large central area of the fort served as a parade ground whilst at the south corner of each fort were the officersâ quarters and mess and at the north corner were the quarters of the Field Officer Commanding. It was proposed that forts along the line were to be connected by a rampart and ditch, dug when an attack was imminent and manned by infantry. The initial armament of each fort was 43 eight-inch smoothbore (SB) guns, two 40 pounder rifled breech-loading guns, and four 13-inch mortars. They were designed to be manned by a war garrison of two field officers, 14 officers and 800 men but this was reduced by a third or half in peacetime.
The Gosport Advanced Line became obsolete almost as soon as it was built. The more powerful guns that were being developed meant that bombardment of the dockyard was possible from a greater distance without attracting counter-fire from the forts. Furthermore, the fort design was not suitable for rearmament with the latest guns. Nonetheless, in 1889, a plan of modification was carried out to the forts, which were remodelled to provide circular concrete gun emplacements for 64 pounder rifled muzzle-loading guns. By 1895, artillery had improved dramatically and the approach to defending Englandâs dockyards had entirely changed. Fixed defences were no longer considered necessary as field batteries were to be employed instead; the landward defences being declared obsolete. In 1900, the forts were used to prepare troops and their equipment for the Boer War. The forts were officially disarmed in 1903 leaving only two machine guns in each.
The open firing space in front of Fort Grange was used by the Portsmouth (later Hampshire) Aero Club in 1910. It became an airfield of the Royal Flying Corps in 1912 who also took over the fort in January 1914. During the First World War, it supplied fighter squadrons, serviced aircraft and trained fighter pilots for the Western Front. In 1916-1917, the School of Special Flying was formed at Grange, which had a worldwide reputation for a revolutionary system of flying training. In April 1918 Grange Airfield became RAF Station Gosport. During the Second World War, it served as a base for Southern Commandâs protection of mainland Britain. Grange became a Naval Air Station, HMS Siskin, in 1946 that served as the base for the first British Helicopter Squadron. This in turn became HMS Sultan in 1956 to which it currently (2024) remains; now serving as the home of the Royal Naval Air Engineering and Survival School and the Defence School of Marine Engineering.
Details
The standing remains, earthworks and buried remains of a polygonal artillery fort built in 1858 to 1862.
PRINCIPAL FEATURES
Fort Grange is situated on low-lying essentially level ground on the west side of Gosport and was originally built to defend the landward western approach to Portsmouth Harbour. The ramparts forming the main enclosure or enceinte comprise casemated barrack rooms, originally covered with earth, on top of which was the terreplein and gun positions; however, the earth covering and gun positions have been removed. The ramparts are built with a trace based on an irregular polygon, essentially forming a detached bastion with an obtuse salient: the main west rampart, originally with the heaviest armament, flanked by further ramparts at the north and south and a rear gorge wall. Two earthen gun ramps lead up from the parade ground in the centre of the fort to the top of each end of the west casemates. Placed centrally at the rear of the fort is a circular keep of last resort. Originally a moat surrounded the entire fort but it is now (2024) largely infilled, where it survives as a buried feature, except around the entrance and interior side of the keep where it survives as a dry moat. Caponiers project from the centre and angles of the west rampart. In front of the west rampart was originally a redan and glacis but these have been largely levelled.
DESCRIPTION
There are two main entrances to the fort. One is set into the gorge wall immediately north of the keep. It provides road access at the rear of the fort via an iron bridge across the now infilled moat and through an entrance flanked with large square stone piers onto the parade ground. Another approach leads across the keep moat (now dry) via another iron bridge, originally including a drawbridge, directly into the rear of the keep.
The KEEP is a circular ring-shaped building with an open courtyard at its centre and a vaulted passageway running through it. The design was such that should one half be destroyed or captured, the other half would stand as a separate structure. It is constructed of red brick with stone dressings and has a stone cordon and earth covering to the roof providing a terreplein with one Haxo casemate. There are twelve gun embrasures facing out from the rear of the keep and eight gun embrasures facing the internal parade ground, enabling the keep to be defended should the main ramparts fall. Each embrasure is lined with granite and some retain the original wooden shutters, faced in iron plates with rifle loopholes. In addition, there are eight musketry galleries or caponiers projecting out into the moat. The rear (east) entrance of the keep has a Romanesque round-headed arch of two moulded orders resting on a pair of columns with scalloped capitals. The letters âFORT GRANGEâ are painted onto the stonework of the arch. Original six-panelled studded double doors lead to a barrel-vaulted passageway through the eastern half of the keep and into the inner courtyard. The internal elevation, facing the courtyard, has wooden-boarded doors with transom lights and six-over-six sash windows with rubbed voussoirs beneath a clerestory of segmental-headed six and eight-paned windows. Some later alterations have been made to the openings and a small brick store built against the courtyard wall. There is a stone dentilled cornice and set of iron railings to the roof parapet.
The interior of the keep originally served as officersâ quarters, barrack rooms and stores but now (2024) accommodates the HMS Sultan Cadet Corp, including offices, classrooms, dormitories, and various stores. The rooms are covered by barrel or groin vaults and retain some historic features, such as fireplaces, iron shutters, panelled doors with brass knobs, iron rings to brace, hoist or move the gun carriages, and flagstone floors. Some historic painted signage also survives to the walls, including one marked âBATTRY. COMMDS. POS.â However, many of the rooms now also contain late C20 or early C21 fixtures and fittings. Wooden-boarded doors lead off each side of the eastern entrance passage to curved corridors providing access to the former officersâ quarters and barrack stores on the left and the former guardroom and prisonersâ cells on the right (now classrooms, accommodation and stores). Beyond these chambers are four large vaulted barrack rooms (now a classroom, dormitories, âmain deckâ and ârecreation deckâ). On the western side of the keep is a further barrel-vaulted passageway. A set of panelled doors nearest the inner courtyard lead off from each side of this passageway to curved corridors providing access to former officerâs quarters (now classrooms, a staff room, WC and store), a former coal store (now a Field Gun Upper Store), and a former straw store (now uniform store). A second set of boarded doors, furthest from the inner courtyard, lead off from each side of the passageway to a barrack store (now a Field Gun Lower Store) and artillery store. Four spiral staircases lead up from the ground floor of the keep to the terreplein, built on two levels, where there are the standing remains of a Haxo casemate facing west, two expense magazines and two shell stores. Brick chimneys rise up through the earth covering. The west side of the keep is approached from the fort parade ground by an iron bridge across the moat, which leads to an entrance with a round brick arch resting on stone impost blocks. The bridge is designed to include a rolling deck that could be withdrawn under the vaulted passageway.
Adjoining the keep is the rear GORGE WALL of the fort, half of which is backed by a denuded earth rampart with a firing step and the other half by vaulted casemates. Brick and stone stairways with iron railings lead up from the earth rampart onto the roof of the casemates. The casemates each originally had two openings with rubbed brick voussoirs facing the parade ground; a six-over-six sash window and timber door with a transom light. However, three of the northern casemates have been altered as a car repair workshop; these casemates have double doors flanked by windows and contain modern workshop fittings. The casemates have pairs of sash windows in the external, outward-facing walls of the fort, although several of these are now blocked. The south-east casemates of the gorge wall are currently unoccupied and boarded up.
The NORTH AND SOUTH âRAMPARTSâ, flanking the main west ârampartâ, consist of casemated barrack rooms, each with nine granite-lined gun embrasures facing out of the fort. There was originally an earth covering to the roof of the casemates and merlons (earthen slopes) between the gun embrasures, but the earth, which originally provided protection from shell fire, has been removed. Some of the gun embrasures retain their original external shutters. The elevations of most of the individual casemates facing the parade ground comprise a central doorway beneath an oeil-de-boeuf (round) window flanked by six-over-six sash windows with rubbed-brick voussoirs. However, some of the casemates have three sash windows and no door. The officersâ quarters and mess, as well as a billiard room, kitchens, day rooms and stores were originally located in the southern casemates, whilst the northern casemates contained the Commanding Officerâs quarters, Master Gunnerâs accommodation, and further barrack rooms and stores. A wide groin-vaulted passageway links most of the casemates internally. The casemates retain some historic features, such as iron rings, gun races and flagstones. However, the north casemates are currently in use as a shooting range, including late C20 and/or early C21 fixtures and fittings. Many original openings are now bricked up. The south casemates are currently unoccupied and boarded up. There were originally Haxo casemates on top of each flank; they remain standing to the north (without the earth covering) but have been removed at the south.
The WEST âRAMPARTâ was built with an outer brick retaining wall rising from the moat to a narrow berm or sentry path running the length of the rampart. Beyond the berm was an embanked earthwork rising up and over the casemates where there was a terreplein, gun emplacements and expense magazines; the earth covering, and gun emplacements have been removed but five, of an original eight, expense magazines remain standing. The east elevation of each casemate has central boarded double doors and dwarf walls beneath huge multi-pane windows filling the whole of the upper section of the arched openings. Internally, each casemate is covered in a brick barrel vault which extended back about half the thickness of the original rampart in depth where a long, narrow vaulted passageway links the casemates internally. Each casemate was fitted out with a ventilation shaft and fireplace; the shaft and chimneys originally rising through the rampart above. They provided barrack rooms for the soldiers, originally fitted out with fold-up iron beds beneath accoutrement racks, as well as cook houses, mess rooms, hospital wards and stores. In 2024, they are in a range of uses, such as a bar, store rooms, changing rooms and washrooms, or otherwise vacant. Some original fixtures survive internally, such as fireplaces, joinery and iron gun rings, but there are otherwise late C20 and early C21 fixtures and fittings and sanitary ware. There are iron railings to the roof parapet of the casemates and to the stairways.
Extending out from the centre and end of the west ârampartâ are the CAPONIERS. The centre caponier is entered via a vaulted passageway from the parade ground, which commences underneath a large central, double flight, brick stairway that leads out onto the top of the casemates. The caponier was originally fitted with three guns firing out of granite-lined gun embrasures in two directions along the moat, as well as musket loopholes to fire out to the west. To each side of the caponier are the soldierâs latrines as well as a sally port or postern providing access to the sentry walk. The flanking caponiers are smaller âdemi-caponiersâ with gun positions firing one way down the flanks of the fort. They each have a lower tier of two gun embrasures beneath rifle loopholes above. Access to these caponiers is via barrel-vaulted passageways entered beneath the fort ramps. The moat surrounding the fort has now been largely filled in where it will survive as a buried feature. Beyond it, at the west, was originally a redan; a V-shaped rampart shielding the west caponier from fire, but this has been levelled, as also appears to have been the case with the glacis beyond it.
The PARADE GROUND of the fort now accommodates a football pitch, three tennis courts, car parking and a brick electricity compound. Two substantial earthen gun ramps lead up from the parade ground to the top of each end of the west casemates, originally onto the terreplein; brick shell stores are built beneath the west end of these ramps. There were four wells with iron hand pumps originally situated around the parade ground. The wells are likely to survive below-ground whilst at least one hand pump remains in place on the south side of the parade ground. Next to the keep, at the south-east edge of the parade ground is the former SERGEANTâS QUARTERS (now Building No 155). This is a rectangular building one bay wide and two bays long with a gabled slate-covered roof. It has a six-pane timber window and blocked oeil-de-boeuf (round) window to the west elevation and two wooden-boarded doors to the south front.
EXTENT OF SCHEDULING
The scheduled area includes the main enceinte of the polygonal artillery fort demarcated by the keep, the north, south and west casemates/ârampartsâ, the rear (east) gorge wall and the surrounding moat (buried or otherwise).
EXCLUSIONS
The monument excludes the late C20 and early C21 fixtures and fittings, vents and sanitary ware within the fort buildings. In addition it also excludes: the garages and other late C20 and early C21 buildings and any basements now situated over the infilled moats outside the fort walls; all electricity compounds and sub-stations, associated structures and junction boxes; all modern (late C20 and early C21) fences or fence posts, railings, gates and gateposts; the paved, tarmacadam or concrete or other surfaces of all modern roadways, pathways, car parks, sports pitches and tennis courts; all modern signs and sign posts, lamps and lamp posts and security cameras; all modern drains and drain covers, fuel tanks, pipes, bins, flags and flag poles, benches and bollards. However, the ground beneath all these features is included.
