Details

The monument includes a martello tower set within a dry moat and with an outer
glacis (sloping bank), and supporting the remains of a later, World War II
observation post. The tower is situated on Radnor Cliff and overlooks a
residential area below and the coastline beyond. It is the most easterly in a
cliff top series of six moated towers, constructed in 1805-6 to guard the
coastline between Hythe and Folkestone, and lies around 400m south east of its
neighbouring tower, no 5.
The slightly elliptical, brick built tower measures up to around 13m in
diameter externally and stands complete to its original height of about 10m.
The upper half of the tower protrudes above the lip of the brick built
retaining wall of the moat, which encircles the base at a distance of around
10m and was intended to provide further protection from both cannon fire and
ground assault. As part of the original design, soil was built up against the
outer face of the moat wall to form a glacis, which slopes away from the lip
of the moat for a distance of around 10m. The glacis has been disturbed along
its north eastern edge by the construction of a modern house, and has been
partly destroyed by the construction of a modern road along its southern edge.
The tower was constructed on three levels, with battered (inwardly sloping)
walls, designed to deflect cannon shot, ranging from 1.6m to around 4m in
thickness, the most substantial section being the wall base on the southerly,
seaward side. The external face of the walls was rendered in a cement mortar,
or stucco, which served to strengthen the outer skin of bricks. A thick
central column rises from the basement to the top of the tower, from which
springs the barrel vaulted first floor ceiling which supports the gun platform
on the roof.
Access into the tower is by way of a first floor doorway, which was originally
approached by a drawbridge across the moat, capable of being raised to seal
the entrance. The bridge no longer survives, although part of the mechanism
used to raise it remains within the tower, above the entrance door. The first
floor was divided into three rooms by wooden partitions, which do not survive,
and provided accommodation for the garrison of 24 men and one officer. Two
fireplaces heated the rooms, which were lit by two windows, one of which was
enlarged to form a door when the tower was reused during World War II, and
the jambs of the second window were cut back to form splays. The openings are
headed by air vents.
The brick lined basement is reached by a trap door leading down through the
suspended timber floor near the entrance. This was used to store ammunition
and supplies, and provision for these includes a vaulted gunpowder store, or
magazine, partly recessed into the thickness of the outer wall. The eastern
partition wall of the magazine was subsequently removed, and two further walls
added, during a later phase of refurbishment. Safety features included lantern
windows in the partition walls, separated from the magazine by panes of glass.
Ammunition lift shafts, linking the gun emplacement to the basement level,
were also inserted within the thickness of the wall at a later date. Cisterns
dug into the basement floor, fed by rainwater pipes leading down from the
roof, were designed to augment the water supply, and a slate water tank,
subsequently installed beneath the floor, still survives.
The open gun platform is reached from the first floor by an internal stone
staircase constructed in the thickest part of the tower wall. The original
wooden door from the head of the staircase remains on the roof. The circular
roof space, designed to accommodate a 24-pounder cannon mounted on a wooden
traversing carriage, retains most of its original features, including the
raised central pedestal which supported the gun pivot, and the raised
perimeter step, with both inner and outer iron gun rails surviving intact. The
operation of the cannon, which had a range of around 1.5km and could be turned
through 360 degrees by a series of rope pulleys, required 10 to 14 men. The
six iron hauling rings used for traversing and preparing the cannon, survive
in the parapet wall which encircles the roof. Four ammunition stores, in the
form of arched recesses, and a smaller niche, thought to have housed a
gunpowder flask, are also set into the parapet wall. The smaller recess was
altered when the adjacent lift shaft was installed. Superimposed onto the
original roof features are the remains of a World War II observation post
comprising a series of brick walls surviving to a height of around 1m.
All modern fences, the modern pond and its stone surround; the stone revetment
along the north eastern edge of the glacis, and all other modern fixtures and
fittings are excluded from the scheduling, although the ground beneath these
features is included.

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

Source: Historic England

Reasons for Scheduling

Martello towers are gun towers constructed to defend the vulnerable south
eastern coast of England against the threat of ship-borne invasion by
Napoleonic forces. Built as a systematic chain of defence in two phases,
between 1805-1810 along the coasts of East Sussex and Kent, and between 1808-
1812 along the coasts of Essex and Suffolk, the design of martello towers was
based on a fortified tower at Mortella Point in Corsica which had put up a
prolonged resistance to British forces in 1793. The towers take the form of
compact, free-standing circular buildings on three levels built of rendered
brick. The towers of the south coast were numbered 1-74 from east to west,
while those of the east coast were identified by a system of letters (A-Z, and
then AA-CC) from south to north.
Although they exhibit a marked uniformity of design, minor variations are
discernible between the southern and eastern groups and amongst individual
towers, due mainly to the practice of entrusting their construction to local
sub-contractors. Most southern towers are elliptical in plan, whilst the
eastern group are oval or cam-shaped externally, with axes at the base ranging
between 14.4m by 13.5m and 16.9m by 17.7m. All are circular internally, the
battered (inwardly sloping) walls of varying thicknesses, but with the
thickest section invariably facing the seaward side. Most stand to a height of
around 10m. Many martello towers are surrounded by dry moats originally
encircled by counterscarp banks, and/or have cunettes (narrower water
defences) situated at the foot of the tower wall. The ground floor was used
for storage, with accommodation for the garrison provided on the first floor,
and the main gun platform on the roof. The southern towers carried a single
24 pounder cannon, whilst the eastern line carried three guns (usually a 24
pounder cannon and two shorter guns or howitzers). Three large, circular ten-
gun towers known as redoubts were also constructed at particularly vulnerable
points, at Dymchurch, Eastbourne and Harwich. All three survive.
As the expected Napoleonic invasion attempt did not materialise, the defensive
strength of the martello tower system was never tested, and the tower design
was soon rendered obsolete by new developments in heavy artillery. Many were
abandoned and fell into decay or were demolished during the 19th century,
although some continued in use into the 20th century as signalling or
coastguard stations and a few saw use as look out points or gun emplacements
during the two World Wars. Of the original 74 towers on the south coast, 26
now survive, and of the 29 on the east coast, 17 now survive. Those which
survive well and display a diversity of original components are considered to
merit protection.

Martello tower no 4 at Cliff Road, Folkestone, survives well despite some
later alterations, and retains a substantial proportion of its original
components and associated features, including the glacis bank. It serves as a
valued local landmark and, when viewed as one of a series of six cliff top
towers, no 4 illustrates the strategically planned integration of the martello
tower system. The construction of an observation post on the roof of the tower
during World War II, demonstrates the continued significance of this location
and provides an insight into the role of coastal defence during the 19th and
early 20th centuries.

Source: Historic England

Sources

Books and journals
Sutcliffe, S, Martello Towers, (1972)
Telling, RM, English Martello Towers: A Concise Guide, (1997)
Telling, R M, Handbook on Martello Towers, (1998)
The Conservation Practice, , South Coast Martello Towers - a report of survey, (1996)

Source: Historic England