Bembridge Fort, Isle of Wight Archaeological Investigations

Bembridge Fort is a largely intact example of a brick built polygonal land fort, which was
constructed between 1862 and 1867 as part of the recommendations of the 1860 Royal
Commission on the defences of the United Kingdom. It is a Scheduled Monument and is owned
by the National Trust, who have commissioned this building recording project.
The project is focused on understanding the Officers’ Quarters at the east end of the Parade
Ground, specifically the sash windows which are in poor condition and require repair work to
the joinery. This repair work needs to be informed by a better understanding of the window
joinery, it’s construction and phasing. In addition to this a programme of building recording
was also required of surviving Second World archaeology at the fort, including two Allan‐
Williams Turrets, a Spigot Mortar Emplacement and features relating to the use of radar on
the site.
The investigation into the Officers’ Quarters including producing a 3D photogrammetric model
of the elevation, which was annotated to illustrate phasing and construction. This showed that
the 1860s elevation has undergone a programme of repairs which is thought to date from the
early‐1930s. At this time the Officers’ Quarters were modified which led to the infilling of
former doors and also saw repairs to the sash window joinery. A further phase of repairs led
to the partial infilling of windows to shorten them in length, and the insertion of double doors
at the south end of the elevation. This date of this phase of work is uncertain, but may date
from between the mid‐1930s to the mid‐1940s.
The investigation into the surviving window joinery was informed by a specialist in architectural
detailing, Charles Brooking, who visited the site. All the main windows have been replaced in
the 1960s but there is varying survival of 19th‐century window joinery (ie shutter boxes etc
fixed into the openings). One of the most important discoveries was the fact that the windows
were originally fitted internally with vertical‐sliding counter‐balanced shutters, a detail widely
used until the 1880s. The unexpected discovery was that the two types of sash window
construction were employed at the Officers’ Quarters, a more expensive construction in
addition to a more economical arched window design.
It is possible that this second form of construction dates from the second, 1930s, phase of work
as investigation into the sash pulleys suggest that work was undertaken to the windows at this
time. Further investigation is needed to better understand the phasing of the joinery, which
will necessitate the removal of the 1960s side panelling to the windows which is obscuring the
earlier joinery.
The investigation into the Second World War archaeology recorded the known features from
this phase, such as the radar buildings and related features, as well as the two Allan‐Williams
Turrets and Spigot Mortar Emplacement. During the investigations, two further Spigot Mortar
Emplacements were identified, in addition to two Motely Stalk emplacements, a Rifle Trench
and an Open Machine Gun Position. These features were also recorded so that an informed
decision could be made of the conservation of the surviving Second World War archaeology
Clearly, there is considerable potential for further work in order to better understand the
Second World War remains, and the surviving 19th‐century sash window joinery. The removal
of some of the 1960s timber panelling internally and externally would greatly enhance
understanding of the surviving 19th‐century joinery, as well as closer examination of the
pulleys. Initial investigations suggest that Bay B is the best preserved of the eight bays because
it retains its 1860s construction with no later adaptations and modifications, and because the
windows have been confirmed as retaining surviving 19th‐century joinery which is of the
superior form of construction.
The conservation of the Second World War archaeology would also benefit from further
research particularly through aerial photograph analysis to better identify surviving features
from this phase. Further on‐site investigation would also help to confirm the functions of newly
identified features from this phase, and how these operated in the Second World War, both in
relation to the fort and the wider military landscape of the Isle of Wight and beyond.