Details

The monument includes St Helen's Fort, a circular 19th century Royal
Commission sea fort lying in the Solent 1km east of Node's Point. St Helen's
Fort was one of a chain of four sea forts in the Solent recommended by the
Royal Commission on the Defence of the United Kingdom in 1860 and designed to
protect Portsmouth dockyard from seaborne attack. Construction started in 1867
and was completed in 1871.

The fort, which is a Listed Building Grade II, is oval in plan and includes
sea bed foundations formed by a ring of cement and brick-filled iron caissons,
the area enclosed by which was dredged and filled with poured concrete. Walls
of Roche, Portland and Bramley Fall stone were constructed upon the
foundations which were 45.7m in diameter, and these in turn formed the base to
a superstructure comprised predominantly of concrete. The fort had two
internal floors, the lowest of which, the basement level, was reached by a
two-level landing stage constructed in 1880 and demolished in 1959 which
extended north from the rear of the fort. A series of brick partitions divides
the basement level radially into compartments for ammunition and storage,
which in turn are divided concentrically by three circular passages. The
outermost passage gives access to nine store rooms. Inside this is the lamp
passage, which runs around the three magazines, each of which originally lay
directly beneath the gun which it supplied and included an ammunition winch.
Access to the magazines is via the ammunition passage. Because of the weight
of the guns the walls on this level are strengthened with cast iron columns.
In the central core is the pump room. Fresh water could be raised by pump from
152m below the sea bed at the rate of 120 gallons an hour, and two water
cisterns are situated above the landing stage entrance, either side of which
are a further two magazines.

Above the basement is the gun floor, which had provision for three guns, each
of which was mounted within a casemate armoured with three layers of five inch
wrought iron, separated by iron and concrete. To the rear of these are the
soldiers' quarters, consisting of a room for five other ranks and another for
one NCO. The roof originally supported a lighthouse and ventilators.

The original scheme was for a fort with 15 guns in casemates, but this
was later increased to 17 with the proposed addition of four further guns in
turrets mounted on the superstructure. However, uneven settlement of the
foundations meant that the size and complexity of the superstructure had to be
radically reduced and as a consequence it was recommended that the fort should
be fitted with a central two-gun turret with a further gun mounted either side
on a Montcrieff mounting. Problems with the latter meant that instead the
lower seaward guns on each flank were mounted on turntables, whilst further
settling of the foundations in 1878 led to the abandonment of plans to mount a
turret. All the emplacements had to be moved to the rear of the fort and in
1880 the turret was replaced by a single 12.5 inch rifled muzzle loader (RML)
firing through an iron-shielded embrasure. Two 6 pounder quick firing (QF)
guns designed to combat torpedo boats were mounted on the fort's roof in 1900,
but removed in 1904. In 1916 two 12 pounder QF guns and two searchlights were
installed on the roof when the area became an examination anchorage for the
searching of suspicious vessels. During World War II the fort mounted two
searchlights in concrete emplacements on the roof and from 1943 a 40mm Bofors
gun was installed in the anti-shipping role, specifically to combat E-boats.
The Bofors was removed in 1945 and the searchlights sold for scrap in 1957.

All structures, fixtures and fittings associated with the conversion of the
fort for recreational purposes and the navigation beacon affixed to the roof
are excluded from the scheduling, although the structures to which they are
attached are included.

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

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.

St Helen's Fort survives particularly well as a standing structure which
retains many of its original fixtures and fittings. Together with contemporary
documentary sources relating to the fort, the remains will offer an insight
into late 19th century military architecture, engineering practices and
strategy as will the adaptation and reuse of the fort in the first half of the
20th century in response to changes in weaponry and tactics.

Source: Historic England

Sources

Books and journals
Cantwell, A, 'Spit Bank and the Spithead Forts. Solent Papers No.1' in St Helen's Fort, (1986), p.27-34
Saunders, A D, 'Fortifications of Portsmouth and the Solent' in St Helen's Fort, (1998), p.142-3
Other
Isle of Wight Council, PRN 1162 - St Helen's Fort,

Source: Historic England