Details

The monument includes a circular, casemated battery, set within an unrevetted
ditch and outer glacis, with associated groynes, jetty and the remains of
later, World War II structures.
Fort Darnet is one of a pair of batteries, its twin being Hoo Fort,
constructed on low islands on opposite sides of the Medway channel. Hoo Fort
is the subject of a separate scheduling. They were built during the 1860s on
the recommendation of the Royal Commission on Defence, and were intended to
provide an inner line of defence to protect the approaches to the naval
dockyard at Chatham. An additional safeguard, in the form of a minefield, laid
across the channel between the forts, was to be employed in the event of war.
The major fortifications at Grain and Sheerness supplied the outer line of
defence at the mouth of the Medway. These fortifications are also the subject
of separate schedulings.
The substantial, two-tiered battery, measures around 56m in diameter
externally, and stands to its original height of about 10m. The brick-built
structure is faced in granite ashlar, with lower courses dressed in Kentish
ragstone. The upper level, smaller in diameter than the tier below, protrudes
above the lip of the encircling ditch, beyond which, a sloping bank, or
glacis, extends for a distance of up to 50m. Traces of associated timber
structures can be seen along the foreshore to the north and west of the fort,
including the remains of groynes, and the jetty onto which supplies and
ammunition were unloaded.
The fort was originally entered at ground floor level, through a passage on
its southern side, and was approached from the jetty by way of a curving
footpath, crossing the southern slope of the glacis. The entrance passage is
no longer accessible, due to flooding of the ditch and lower level of the
fort, although the upper tier is reached by way of a modern footbridge from
the roof of the brick, vaulted coalstore situated within the ditch. The lower
tier contains the magazine and accommodation casemates, arranged in concentric
rings around a solid concrete drum at the centre of the fort. The outer ring
of magazine chambers represent the shell and cartridge stores, which were
entered from the magazine passage in front. Lift shafts also rise from the
passage enabling the rapid deployment of ammunition to the gun floors above. A
sophisticated lighting system formed part of the safety features of the
magazine and consisted of a lantern window above the door to each chamber, and
separated from it by a pane of glass. The lamps were carried above the
magazine passage on horizontal, overhead rails, contained within zinc
conduits, and were served by a ring of lamp chambers, accessed from the
barrack rooms beyond. In turn, the barrack rooms were entered from an open
corridor, or light well, which surrounds the central drum. Steps led up from
the corridor to the top of the drum, which provided a small, open parade at
the centre of the gun level.
The gun level contains an outer ring of 11 interconnecting, vaulted casemates,
arranged around the parade and reached by narrow bridges across the light
well. The casemates were designed to accommodate eight 9in, and three 7in
rifled muzzle-loaders mounted on traversing carriages. The casemates retain
many of their original features, including the iron shields inserted into the
embrasures for the protection of the gunners. Rope mantlets were also hung
behind the shields to reduce casualties from masonry splinters in the event of
enemy fire, and some of their suspension bars and rings survive. The chamber
behind the gun room was intended to provide wartime accommodation for the
gunners, and was enclosed at the rear by a glazed screen, designed to be
removed before the guns were fired. The screens have now been lost, along with
the glazed verandah, originally constructed around the parade perimeter. The
verandah formed part of the rainwater collection system for the fort, and was
supported on hollow cast iron columns, through which rainwater was fed to a
cistern beneath the parade.
Reuse of the fort during World War II is represented by a minewatching
post, situated on the roof, overlooking the Medway to the north and west, and
an observation post constructed within the embrasure of a southern casemate,
with views towards South Yantlet Creek.
All modern fixtures and fittings, such as the temporary footbridge across the
ditch and the remains of the modern jetty on the south western edge of the
glacis are excluded from the scheduling, although the ground beneath all of
these features, or the structures to which they are attached, is included.
Also excluded are the concrete hulks from World War II, laid up along the
south western side of the island during the late 20th century, where they fall
within the area of protection.

MAP EXTRACT
The site of the monument is shown on the attached map extract.
It includes a 2 metre boundary around the archaeological features,
considered to be essential for the monument's support and preservation.

Source: Historic England

Reasons for Scheduling

The Royal Commission fortifications are a group of related sites established
in response to the 1859 Royal Commission report on the defence of the United
Kingdom. This had been set up following an invasion scare caused by the
strengthening of the French Navy.
These fortifications represented the largest maritime defence programme since
the initiative of Henry VIII in 1539-40. The programme built upon the
defensive works already begun at Plymouth and elsewhere and recommended the
improvement of existing fortifications as well as the construction of new
ones.
There were eventually some 70 forts and batteries in England which were due
wholly or in part to the Royal Commission. These constitute a well defined
group with common design characteristics, armament and defensive provisions.
Whether reused or not during the 20th century, they are the most visible core
of Britain's coastal defence systems and are known colloquially as
`Palmerston's follies'. All examples are considered of national importance.

Fort Darnet survives well, and retains many of its original components,
including its associated glacis bank. When viewed as one of a pair of
contemporary batteries, the fort provides a valuable insight into the wider,
strategic defence of the Medway during the late 19th century, and its later
reuse demonstrates the continued importance of its location in the defence of
Britain during World War II.

Source: Historic England

Sources

Books and journals
Crowdy, R, Medway's Island Forts, (1979)
Gulvin, K R, The Medway Forts, (1976), 18-19
Smith, V T C, Strategic Study of Kents Defences - Fort Darnet , (1999)
Other
RCHME, AP Ref: TQ8070/4/20 NMR SF2692, (1986)
Title: Ordnance Survey 25" Kent sheet XII.13 (surveyed 1861-2)
Source Date: 1909
Author:
Publisher:
Surveyor:

Source: Historic England