Details

The monument includes the night shelter of a World War Two bombing decoy,
situated south of the Stour river valley, some 450m south west of Spinnel's
Farm. It occupies an elevated position on a ridge of high ground overlooking
the decoy area to the south.

Documented in contemporary records as `WRI Spinnels Farm', the site was a
World War II N series (Naval) decoy controlled from Harwich. This class of
decoy was designed specifically for the protection of naval installations - in
this case the Sea Mine Depot at Wrabness sited two miles to the north. The
site is a QF type replicating the night-time fires one would expect from a
night-time bombing raid on a specific target mostly by using basket fires.

The decoy site was an elaborate affair and would have utilised numerous fires
ignited electrically from an earth-covered bunker or night shelter. The
night shelter which housed the electrical ignition equipment for the fires
overlooks the decoy area to south east. It is a brick and concrete bunker with
a maximum external length of 12m and is covered with earth to protect it from
stray bombs. It is divided into two main rooms, the Operations Room (4m by
3.2m internally), the Operations Room (3.2m by 3.8m internally), and also has
a small toilet room in between the two. The Operations Room has an escape
hatch with a steel ladder; remains of the flue outlet for the stove and four
ceramic pipe outlets, thought to have been for chanelling the electrical
switchgear cabling to the outside, survive. In the Engine Room the engine bed
remains, with three steel exhaust outlet pipes leading through the north wall
to the outside.

War Office documents relating to the equipment and manning of the Bombing
Decoy WRI Spinnels Farm show that it was operational in August 1941 (the
earliest reference to it is dated 1st August), and was certainly in use in
March 1942 (latest written reference); although no further specific
documentary references can be found, it may have continued in use through to
the end of the war.

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

World War II saw the emergence of aerial bombardment as a decisive instrument
of warfare, and to counter this threat, the United Kingdom maintained a
flexible and diverse mechanism of air defence throughout the war. This
included the early warning of approaching aircraft, through radar and visual
detection, and the local defence of towns, cities and other vulnerable points
using anti-aircraft gunnery and balloon barrages. But less conspicuously, many
potential targets were shadowed by decoys - dummy structures, lighting
displays and fires - designed to draw enemy bombs from the intended points of
attack.
Britain's decoy programme began in January 1940 and developed into a complex
deception strategy, using four main methods: day and night dummy aerodromes
(`K' and `Q' sites); diversionary fires (`QF' sites and `Starfish'); simulated
urban lighting (`QL' sites); and dummy factories and buildings. In all, some
839 decoys are recorded for England in official records, built on 602 sites
(some sites containing decoys of more than one type). This makes up the
greater proportion of the c.1000 decoys recorded for the United Kingdom.
The programme represented a large investment of time and resources. Apart from
construction costs, several thousand men were employed in operating decoys,
the fortunes of which were closely tied to the wartime targets they served.
The decoys were often successful, drawing many attacks otherwise destined for
towns, cities and aerodromes. They saved many lives.
Urban decoy fires were known as `SF', `Special Fires' and `Starfish', to
distinguish them from the smaller `QF' installations. Each town was protected
by a cluster of these decoys, the most technically sophisticated of all the
types, with each Starfish replicating the fire effects an enemy aircrew would
expect to see when their target had been successfully set alight. The decoys
included variation in fire type, duration of burning and speed of ignition. In
a permanent Starfish all fire types were used, set in discrete areas defined
by firebreak trenches and controlled from a remote shelter. The whole array
was linked by a network of metalled access roads. `Temporary Starfish' (all
built in 1942 to counter the threat from the so-called Baedeker raids against
historic towns and cities) only had basket fires. In all, 228 decoys with a
Starfish component are recorded in England, 37 of which were `Temporary
Starfish', and the rest `Permanent'. The Permanent sites were located mostly
in central England, close to the urban and industrial targets they were
intended to protect; temporary sites, like the Baedeker targets they were
protecting, were confined to southern and eastern England.
QF sites were first provided for the night protection of RAF airfields, but
from August 1941 their role was extended to protect urban centres. Although
similar to Starfish, they differed in being considerably smaller, using a
limited range of fire types and being sited for the local protection of
specific vulnerable points rather than whole cities or conurbations. These new
QF sites of 1941-2 fell into four groups, for the protection of: urban and
industrial targets (the `Civil Series', located mostly in the west Midlands,
north-west and in the Middlesbrough area); Royal Navy sites (these were few in
number and sited to protect coastal bases); Army sites, to protect ordnance
factories or military installations (these existed in a sparse belt running
from central southern England into the west Midlands); and oil installations
and tank farms (the `Oil QF' sites). In all, only about 100 QF sites were
operational in England.
Very little now survives of any of these decoys, most having been cleared
after the war. All sites with significant surviving remains will be considered
of national importance, as will those where a well-preserved night shelter
has been identified.

The survival of major components of the World War II bombing decoy documented
in wartime records as `WRI Spinnels Farm' is of particular interest to the
study of bombing decoy design. The decoy is a World War II N series (naval)
decoy, one of an original deployment of five in Essex of which WRI Spinnels
Farm is one of only two which survive in good condition. The other decoy at
Kirby-le-Soken, the subject of a separate scheduling, can be seen as a partner
to this one in the defence of Harwich's naval installations, Spinnels Farm
having been designed to replicate a successful bombing raid on the Sea Mine
Depot at Wrabness, and Kirby-le-Soken to replicate a successful raid on
Harwich dockyard.

Source: Historic England

Sources

Books and journals
Dobinson, C S, Twentieth Century Fortifications in England: Volume 3. Bombing Decoys of WWII, (1996), 116-8
Other
Black and white vertical, RAF, 106G-UK 1673-3161, (1946)
Colour prints in ESMR, Nash, F, (1999)
Tyler, S, MPP Film , (2000)

Source: Historic England