Early 20th century gun battery at Bant's Carn, St Mary's

Reasons for Designation

The Isles of Scilly, the westernmost of the granite masses of south west England, contain a remarkable abundance and variety of archaeological remains from over 4000 years of human activity. The remote physical setting of the islands, over 40km beyond the mainland in the approaches to the English Channel, has lent a distinctive character to those remains, producing many unusual features important for our broader understanding of the social development of early communities. Throughout the human occupation there has been a gradual submergence of the islands' land area, providing a stimulus to change in the environment and its exploitation. This process has produced evidence for responses to such change against an independent time-scale, promoting integrated studies of archaeological, environmental and linguistic aspects of the islands' settlement. The islands' archaeological remains demonstrate clearly the gradually expanding size and range of contacts of their communities. By the post- medieval period (from AD 1540), the islands occupied a nationally strategic location, resulting in an important concentration of defensive works reflecting the development of fortification methods and technology from the mid 16th to the 20th centuries. An important and unusual range of post- medieval monuments also reflects the islands' position as a formidable hazard for the nation's shipping in the western approaches. The exceptional preservation of the archaeological remains on the islands has long been recognised, producing an unusually full and detailed body of documentation, including several recent surveys.

The distinctive form of gun batteries developed at the end of the 19th century differed fundamentally from earlier batteries and provided the first application of principles that came to dominate the design of such defences in the later 20th century. Their design and location reflects major developments in armament technology, strategic thought, the nature of the perceived threat and defensive policy. By the mid 1880s an effective breech-loading system had considerably improved the speed of re-loading guns. Hydraulic and compressed air systems enabled the recoil of guns to be absorbed, allowing guns to be located on fixed centrally pivoted mountings which improved accuracy and speed of firing. Lighter steel barrels and improved propellants gave greater muzzle velocities and range without corresponding increases in gun size and weight, thereby increasing the manoeuvrability of the guns. Brass cartridge cases also increased the speed of re-loading. The invention of smokeless powder reduced the visibility of guns on firing. Coupled with these advances, the development of new range-finding equipment and electrical communications considerably increased the speed and accuracy of target position finding and the control and coordination of armament. These technological changes revolutionised the nature of field fortification considered appropriate to house the guns. Priority was given to open emplacements with fixed gun mountings and low profile earthwork fortifications, merging with the surrounding terrain to make them hard to target while allowing the guns maximum manoeuvrability. Early applications of these new principles of fortification were made in the later 1880s in the context of infantry reboubts in south east England, their form characterised as the `Twydall Profile'. During the 1890s variants and developments of the Twydall Profile dominated new land fortifications for infantry and artillery, providing a major influence on the design of the defences constructed on the Isles of Scilly during its 1898-1906 phase of fortification.

The battery at Bant's Carn has survived well, preserving the original form of both its earthwork and built structures and having the most intact survival of original metal fittings of any of the batteries in the Scilly defensive system of this phase. Such complete survival of a battery from this phase is rare and of much importance for our knowledge of the development of modern artillery defences. Most other components in the contemporary defensive system, that included this battery as a major integral part, survive well. Spatially, the rare survival of such a complete defensive system allows the relationships of its components to be studied against their armament capabilities and the strategic methods by which those defences were intended to be used, in the controlled background of a single location. The system of defences to which this monument contributed was directly inspired by considerations of national defence; as such it also has a wider historical importance whose immediate context is defined by the national defence reviews which led both to the implementation and later the abandonment of the naval base which this battery was designed to protect.

Details

The monument includes a large gun battery situated on a natural knoll known as Bant's Carn on the north west coast of St Mary's in the Isles of Scilly. The battery was built between 1902 and 1905 as part of a defensive system designed to protect a naval signalling and re-fuelling station then being established on the Isles of Scilly. The battery is contained within a substantial rampart around the top of the knoll, its forward flank facing north with a field of fire commanding the high water approach across Crow Bar to the islands' military and administrative centre on the Garrison. It has two concrete emplacements for 12-pounder quick-firing (QF) guns set into the rear of the forward flank. Behind the emplacements, the rampart encloses a small levelled interior around a deep lightwell giving access to an underground magazine and stores. An access track curves south from the western end of the parade, leading to the battery caretaker's quarters beyond the south side of this monument. The knoll supporting the battery forms the north west tip of a broad shelf on the island's north west coast; records indicate that the knoll was formerly capped by a rock outcrop that was extensively quarried away to build the battery. As completed the knoll was re-profiled on all sides by the addition of a subrectangular steep earthen rampart measuring 55m east-west by up to 45m north-south across its base; its height varies with the underlying slope, rising up to approximately 6m high on its north west scarp but only 1m high on the south. The top of the rampart encloses an ovoid internal area measuring approximately 30m east-west by up to 12m north-south, sheltered behind the straight crest of the rampart's forward flank and a much higher curving crest of the southern rear flank. The concrete gun emplacements are situated 15m apart in the rear of the forward flank crest. Each emplacement includes a raised pedestal whose surface contains the metal studded base for the gun mounting. Along its forward edge, the pedestal is shielded by a low curved parapet from which a chamfered apron extends to meet the rampart surface. The rear edge of the pedestal is angular, dropping vertically to the battery interior, with concrete steps descending from each side of the pedestal. The emplacements retain their original metal handrails, supported by cast-in metal brackets, along the rear edge of the pedestals and steps. The rear faces of the pedestals contain recessed lockers to house shells and cartridges required for immediate use. Between the emplacements in the battery interior is the rectangular lightwell, 9m long by 2.5m wide and 4m deep, faced with concrete and with steps descending from the western end to the underground magazine and stores. The upper edges of the lightwell and the side of the steps also retain their original handrails; their hooked terminals beside a gap at the western end secured chains designed to be removed to facilitate the lowering of ammunition supplies to the magazine below. The northern face of the lightwell has a date-stone marked `1905', flanked on each side by a large metal ventilator pipe rising up the upper surface: the ventilators serve each of the magazine's two principal rooms to maintain an even low humidity level essential for the preservation of the explosives. The battery's underground rooms open off the north side and both east and west ends of the lightwell. The doorway on the north side gives access to the brick-vaulted magazine, subdivided into two rooms by a partition wall containing a central door. The magazine's eastern room was the shell store, with the direct access from the lightwell and lit by a window retaining its metal grille. The western room was the cartridge store, accessed only by the doorway from the shell store. To reduce the risk of igniting the powder, the cartridge store was lit by lamps set in niches in its wall with the lightwell; the lamps were sealed from the interior of the store itself and were placed into the niche by a hinged window on the lightwell side; the hinged frames still survive in the niches at this monument. The small rooms at each end of the lightwell provided further storage and service facilities for the fuses, cartridge-store lamps and other materials for the guns' routine maintenance. The eastern room was lit by a window retaining its metal grille. Behind the emplacements and lightwell the battery's levelled interior extends little further than was necessary to provide access around the top of the lightwell. Its surface is approximately 1.5m below the rampart's forward crest but to its rear, the rampart rises 2.5m. The eastern end of the interior corresponds with a dip in the rampart crest. On the west, beyond the steps up to the western emplacement, the rampart crest is broken by a levelled access track, about 2m wide, which curves south around the western end of the rampart and towards the battery caretaker's house. The house built on a concrete- revetted stance levelled deeply into the rear of the knoll just beyond the southern edge of the battery's rampart; this house is now a private dwelling and is not included in the scheduling. The historical context which gave rise to this monument is well-documented. In the 1890s, a joint army and navy review of the nation's coastal defences proposed the Isles of Scilly should become an advanced naval signalling and re-fuelling station, to be classed as a defended port, in view of their strategic position against perceived threats from French Atlantic naval bases. Implementation of these proposals between 1898 and 1901 produced two complementary 6-inch gun batteries served by a barracks/caretakers' block on the Garrison, the south western promontory of St Mary's, to cover the deep water approach to the islands. By 1902, the 6-inch guns of these batteries were felt to give inadequate defence against potential attack from motor torpedo boats; a proposed third 6-inch gun battery was abandoned in favour of two 12-pounder quick-firing gun batteries, one above Steval Point on the west coast of the Garrison, the other forming this monument at Bant's Carn, covering the previously undefended shallow-water approach usable at high tides to the island's strategic focus. Most other structures of the fortification system in which this monument was designed to operate were located on the Garrison and still survive, including coastal searchlight emplacements and their control posts at Woolpack and Steval Points, with their electricity supply generator housed in an 18th century battery between them. An artificer's workshop for the maintenance of the all the batteries' guns and mountings survives near the summit of the Garrison. During construction of these defences, national defence policy underwent a radical shift. German power replaced that of France as the dominant threat, a re-orientation strengthened by the signing of the Entente Cordiale in 1904. In the resulting re-alignment of the nation's defences to the east, detailed in the Owen Report of 1905, the Isles of Scilly were abandoned as a naval station and, with little commercial importance, they also lost their defended port status. The batteries on Scilly were ordered to be decommissioned, their guns being dismantled in 1906 and removed to storage in Falmouth in 1910. By the time of this policy change, the 12-pounder guns had been mounted at the Steval Point Battery and were approved but not mounted at Bant's Carn, where construction of the battery had only recently been completed. Consequently, this monument was built as a 12-pounder battery but never armed. The window-blockings are excluded from the scheduling.

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

Legacy

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

Legacy System number:

15439

Legacy System:

RSM

Sources

Books and journals
Stevenson, I V, Some West Country Defences, (1989), 11-26
Saunders, A D, Fortress Britain, (1989)
National Trust, , S Cornwall Heritage Coast, , St Anthony Battery; A short history and description, (1994)

Other
Title: 1:25000 Ordnance Survey Outdoor Leisure Map, No. 25: Isles of Scilly Source Date: 1982 Author: Publisher: Surveyor:
Title: 1:2500 Ordnance Survey Maps; SV 9012 & SV 9112 Source Date: 1980 Author: Publisher: Surveyor:
consulted 1993, Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7488, (1988)
Report for Cons SW, Feb 1994, Linzey, R and EH Architecture Branch, Recs for Incr Statutory Protectn to Woolpack & Steval Batteries, Cons SW, (1994)
Letter dated 3/11/1993, J Guy, Fortress Study Group, Letter to J Ratcliffe, CAU, re Scilly defences, 1902-1910, (1993)

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