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 earthwork defences developed at the end of the 19th
century differed fundamentally from the high-profile fortifications around
earlier strongpoints and provided the first application of principles that
came to dominate the design of such defences in the 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, technological advances had considerably improved the accuracy
and range of guns, their speed of fire and manoeuvrability. The development of
new range-finding equipment and electrical communications increased the speed
and accuracy of target position-finding and the control and coordination of
armament. These developments revolutionised the nature of field fortification
considered appropriate to defend artillery batteries and other key positions.
Priority was given to low profile earthwork defences which were hard to target
by the new long-range artillery while allowing the defensive guns maximum
manoeuvrability; defence against close quarters ground approach was provided
by the newly-developed barbed wire entanglements reinforced by machine-gun and
rifle cover across the unobstructed fields of fire provided by the low
ramparts. 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 defended barracks and caretakers' quarters with associated PF cell at
Greystones survive well, preserving the original form of their earthwork and
built structures with only minor modifications. The intact survival of such
quarters and its ancillary buildings from this phase is rare, but this
monument is particularly unusual in the enclosure of those quarters within
their own distinct circuit of earthwork defences, separate from the gun
batteries of the fortification system. The design of those earthworks and
their associated features provide valuable information on the development of
modern fortifications. The monument is an integral part of a contemporary
defensive system whose other related components also survive well. Spatially,
the rare survival of such a complete defensive system allows the relationships
of its components to be studied against contemporary armament capabilities and
the strategic methods by which those defences were intended to be used, in the
controlled background of a single location. The defensive system 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 to the
implementation and later the abandonment of the naval base which these
defences were designed to protect.
Details
The monument includes a barracks, caretakers' quarters and position-finding
cell, all enclosed within earthwork defences on the south west of the summit
plateau of The Garrison, the south western promontory of St Mary's in the
Isles of Scilly. The quarters were built between 1898 and 1901, serving two
nearby and contemporary gun batteries, the Steval and Woolpack Batteries. This
monument and the batteries formed part of a defensive system designed to
protect a naval signalling and re-fuelling station then being established on
the Isles of Scilly. These defences remained operational until 1906, with
limited reuse of the batteries during World War II.
The monument was constructed with a central caretakers' quarters, capable of
conversion to a barracks, served by wood and coal stores and earth closets
housed in ancillary buildings around the periphery of the monument interior. A
position-finding post was also built into the south west of the rampart. The
internal buildings are contained within a subrectangular defensive enclosure
with rounded corners, visible as an outer and inner rampart separated by a
broad ditch.
The monument's earthwork defences measure up to 85m north east-south west by
75m north west-south east externally. The outer rampart is 4.8m wide, rising
c.1m from the external ground surface and descending c.1.2m along its inner
face to the floor of the ditch. Part of the outer rampart's north east side
has been levelled by modern garden landscaping.
The ditch is flat-bottomed, 7.3m wide at the base and ranging from 13m-17m
wide from crest to crest of its defining ramparts. The ditch was designed to
be filled with barbed wire entanglements secured by retaining spikes. The
outer limit of those entanglements was marked by a fence supported by metal
stanchions along the outer lip of the ditch; the sawn-off stanchion bases of
this fence, which appears on early maps of the monument, still survive,
including along the north east sector where the adjacent outer rampart has
been levelled.
The long outer slope of the inner rampart rises 3m from the base of the ditch
to its crest, which defines the monument's subrectangular interior measuring
42m north east-south west by up to 33m north west-south east. The inner slope
of the inner rampart descends 2.4m to the interior surface, with buildings
around the periphery of the interior levelled into the rampart slope along
parts of each side; the inner slope's profile is also stepped by a broad
terrace for much of its length.
The entrance through the defences is on the north east, by a track through
breaks in the ramparts and a causeway over the ditch. A formal gate was
inserted in the inner rampart break, its sides neatly revetted by granite
walling accompanied by granite gateposts. Metal fittings also survive on the
revetment walls for former higher-level obstructions above the gate.
Occupying the centre of the interior is a caretakers' and barrack block,
large, flat roofed and faced with granite. The block has a subrectangular
plan, up to 22m long, north east-south west, by 8.5m wide with projecting
wings at each end of its south east face separated by a central verandah. This
building was subdivided into two married quarters which shared kitchen and
washing facilities, but was designed for easy conversion into a barracks for
24 men and two NCOs in time of war. That central block is excluded from the
scheduling but the ground beneath is included. Flat-roofed brick-built
ancillary buildings are levelled into the inner slope of the inner rampart
around the interior's periphery. On the north west, these include a long
narrow range which housed the earth closets for both sexes, still retaining
some original fittings, together with an earth store and stores for coal and
wood. Shorter rectangular buildings housed further storage space on the north
east and south east sides of the interior.
On the south west side of the interior, a position-finding (PF) cell was built
into the inner rampart's inner slope and crest. The cell is a small two-storey
concrete-faced structure, c.5m long, NNE-SSW, by c.3m wide externally. Its
upper storey projects slightly above the rampart crest, leaving an observation
slit, now glazed, facing SSW beneath the roof's shallow forward pitch. The
lower storey communications room is sunken below the barracks interior ground
level. The NNE rear wall of the PF cell is recessed into the rampart slope
which is revetted to each side by concrete facing. In the rear wall is a door
to each storey, one above the other; the upper door is reached by its original
metal stairframe retaining its metal railings. The panelled lower door is
reached by concrete steps descending from ground level. This PF cell was built
in or shortly after 1901, following completion of most of this monument and
the two nearby batteries with which it operated. Its function was to determine
target location and range; this information was then relayed to batteries'
guns by electric telegraph. It also operated in conjunction with searchlight
emplacements on the coast at Woolpack and Steval Points, together with their
observation posts on the coastal slopes above them, all coordinated by
telegraph cable links. The PF cell in this monument replaced the earlier
technology of Watkins depression range-finders initially mounted on raised
positions in each battery.
The Garrison's commanding position made it the focus for successive phases of
fortification on Scilly from the later 16th century. 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 a fortification system whose chief
components were two complementary 6-inch gun batteries, the Steval Battery to
the north west and the Woolpack Battery to the south east, to cover the deep
water approach to the islands, served by the defended barracks/caretakers'
quarters in this monument between them.
The similar defences provided for the barracks and the batteries reflect the
latest fortification designs and technology available at the time, their low
profile rendering them difficult to locate and target by distant enemy gunners
while the use of barbed wire entanglements in the concealed ditch provided
control against close approach.
By 1902, the 6-inch gun batteries were felt to give inadequate defence against
motor torpedo boat attack; a proposed third 6-inch gun battery was abandoned
in favour of two 12-pounder quick-firing gun batteries, one above Steval
Point, 200m WNW of this monument, the other at Bant's Carn on the north west
coast of St Mary's. The completed system of fortifications in which this
monument operated also included the searchlight emplacements and observation
posts mentioned above at Woolpack and Steval Points, together with their
electricity supply generator housed in an 18th century battery between them.
An artificer's workshop for the maintenance of the batteries' guns and
mountings survives on the summit of The Garrison, 85m east of this monument.
During construction of these fortifications, 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. Consequently, though the defences had been used for coastal
defence training, their guns were dismantled in 1906 and by 1910 had been
removed for storage in Falmouth.
The central building of the barracks and caretakers' block, all modern fences
and garden furniture, the garden pond and chicken runs are excluded from this
scheduling but the ground beneath them is included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
