Exploring Kent's Past

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Monument details

Summary

The Drop Redoubt was a key element of the Western Heights fortifications. Occupying the eastern end of the ridge and dominating the town, port and seaward approaches, it is essentially a pentagonal fort designed to control the land front as a self-defensible work but was also linked to the linear defences that guarded the Heights as a whole. The 1840's and 1850's saw renewed concerns about the re-emergence of French power and significant developments in weapons technology resulted in a re-appraisal of the nation’s defences. One of the most major additions to the Drop Redoubt fort which was a result of this re-appraisal comprised two-storey caponiers at four corners of the redoubt, for defence of the ditch itself. This also enabled new casemated gun rooms to be built behind the curtain wall, reached via the caponiers, to provide flanking fire along the ditches of the North Lines and the North-East Line. The principal function of the caponiers was to flank the ditch of the redoubt with both carronade and musketry fire to prevent an attacker gaining a lodgement next to the curtain wall or attempting to scale or mine it. (location accurate to the nearest 1m based on available information)

Monument Types

• CAPONIER (Disused, Post Medieval to Modern - 1858 AD? to 1945 AD?)

Full description

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The Drop Redoubt was a key element of the Western Heights fortifications. Occupying the eastern end of the ridge and dominating the town, port and seaward approaches, it is essentially a pentagonal fort designed to control the land front as a self-defensible work but was also linked to the linear defences that guarded the Heights as a whole. The major phase of construction, during the war with France, was between 1804 and 1816, although work had begun from c1782. The 1840's and 1850's saw renewed concerns about the re emergence of French power and significant developments in weapons technology resulted in a re-appraisal of the nations defences. Numerous improvements were made to the defences on Dover's Western Heights in the years immediately following this re-appraisal and by 1860 new works were in full progress on the Heights and by the middle of the decade several major modifications and additions had been made to the Drop Redoubt. One of the most major additions comprised two-storey caponiers at four corners of the redoubt, for defence of the ditch itself. This also enabled new casemated gun rooms to be built behind the curtain wall, reached via the caponiers, to provide flanking fire along the ditches of the North Lines and the North-East Line. The principal function of the caponiers was to flank the ditch of the redoubt with both carronade and musketry fire to prevent an attacker gaining a lodgement next to the curtain wall or attempting to scale or mine it. In addition, to prevent an attacker gaining a position in the angles or top of the counterscarp wall, musketry loopholes in the face walls of the caponiers covered the top and salient angles of this wall. The walls of each caponier were protected from attack by enfilade fire from musketry galleries behind the adjacent curtain wall.

The caponiers are rectangular in plan with vertical walls executed in a hard brick laid to English Bond. The walls, which rise to the full height of the curtain wall, have stone gutters
behind the capping course and sandstone blocks at the corners. The tops have a steeply-scarped and profiled earth and turf bomb-proofing layer with brick-built ventilator shafts projecting through. The flank walls (defending the curtain wall) contain embrasures and loopholes on two levels: the ground floor comprises carronade embrasures flanked by musketry loopholes, while the first floor contain only musket loopholes. Apart from tooled sandstone sills and lintels, both the carronade embrasures and the musket loopholes are of a form used throughout the Western Heights, with brick-built anti-ricochet steps. Ventilators of earthenware pipe are placed above each group of loopholes with their ends flush with the exterior wall. The face walls contain two loopholes, each made from a single sandstone block, on each floor. Those on the ground floor are each placed under a semicircular arch and the section of face wall beneath the arch is battered back into the body of the caponier, creating a shallow vault which is pierced by a murder hole in the form of a narrow slot. At each corner of the face wall are triangular-shaped buttresses with sandstone capping courses; a similar smaller buttress is placed between the arches. The shape of the buttresses prevents the corners, and the area between the relieving arches of the caponiers, becoming a ‘blind spot’ and being used as lodgements by an attacker.

The interior of each caponier is formed from two casemates, each of two storeys with a semi-circular vault. They are of brick laid to English bond with the vaulting running at right angles to the flank walls. The two vaults meet at a heavy spine wall pierced by a tall central arch and by two semicircular, two-storey arches allowing access between the casemates and the galleries. Fireplaces are in the spine wall, one per casemate. The ground floors had suspended timber floors resting on dwarf-walls, though behind the carronade embrasures these gave way to solid brick or stone rectangular platforms to take the wear and tear caused by the recoil of these heavy weapons. The first floor comprises galleried walkways of slate slabs running parallel to the flank walls and set into the sides of the arches. The walkways are carried on wrought-iron ‘I’ section beams and have cast handrail stanchions. The murder holes are accessible by slots in the slate floor, although as these have been sealed their exact form is not apparent. (information taken directly from source) (1)

A plan of the fort which was surveyed in 1858, with annotations from 1871 and 1881, shows the caponiers in detail alongside all of the other major additions which were made to the fort under the 1860's scheme of improvements. (2)

A plan dated to 1866 (approximately at the time when the the caponiers where completed) shows the interior detail of the caponiers and the gun rooms. (3)

<1> English Heritage, 2000, The Western Heights, Dover, Kent. Report No 3 The Drop Redoubt: A 19th-Century Artillery Fortification (Unpublished document). SKE13677.

<2> War Department, 1871-1881, Dover Drop Redoubt Plan Shewing Occupation (Map). SKE51531.

<3> Unknown, 1866, Dover Defences, Western Heights, Drop Redoubt – Record Plans of Caponieres (Map). SKE51533.

Sources and further reading

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