Landguard AAOR – Subterranea Britannica

Written by Nick Catford on 05 February 2005.

During WW2 the anti-aircraft guns serving the Harwich Gun Defended Area (GDA) were controlled from the Gun Operations Room (GOR) in a converted Martello Tower (Q Tower) in South Hill, Felixstowe. In about 1943 GOR’s were renamed Anti Aircraft Operations Rooms (AAOR)

After the war, anti aircraft defences were kept on minimum care and maintenance until 1949 when the threat from the East became very real.

In 1950 a rapid expansion in ant-aircraft defences was implemented with a plan to build purpose built AAOR’s covering all the GDA’s with a number of new and eventually automated gun sites.

The AAOR covering the Harwich GDA was to be built at Mistley but as an interim measure a temporary building was required. By this date the War Department preferred to use government owned property rather than requisitioned land so rather than reactivate the wartime Q Tower a new location at Landguard Fort in Felixtowe was selected.

The AAOR was not located in the fort itself but in ‘Left Battery’ one of the outlying Victorian gun batteries located close to the fort. Coastal artillery was already controlled from a plotting room inside the fort.

The Left Battery dates from the 1891 and consisted of three gun emplacements housing two 6-inch and one 10- inch guns set within a substantial earthwork. The 10-inch RBL utilised a Hydro-Pneumatic disappearing mount (similar to a Moncrieff) which required a very deep emplacement allowing the gun to be retracted below the top of the emplacement. The Hydro-Pneumatic emplacement was selected at the location for the AAOR. It was roofed over with a brick extension to the rear forming the front of the new building.

Inside two large rooms were provided one was the plotting room and the other the GPO frame room. These were access from a short corridor along the front of the building. The operations room had a circular plotting table in the centre of the room with a raised dais around two sides with four plotting positions overlooking the table. Each position had a 20 line keyboard set into the desk. From one of these positions the controller could view the activity on the plotting table and give orders to the gun sites in his sector.

The GPO room next door had a bank of batteries against the back wall with a battery charger and the Main Distribution Frame against the partition wall. A GPO apparatus rack stood in the middle of the room containing signaling units, keyboard speech circuits and telephone jack speech circuits.

During the 1950’s the three emplacements of Left Battery were backfilled and earth was banked up at the rear. All that was visible were the aprons for the 6-inch emplacements and the roofed over 10-inch (the AAOR). Left Battery remained in this state until September 2000 when English Heritage began an archaeological dig, exposing the emplacements and their rears.

Once the earth was removed it was possible to enter the AAOR where a black painted board showed the layout of the Harwich and Felixstowe area anti aircraft guns was found. Each site was marked on this board and had indicator lamps which shoed if it was manned and/or firing. An anti gas door frame was also found in situ in the entrance passage.

The internal structure of the Hydro-Pneumatic emplacement could clearly still be seen with the internal curvature and overhand visible in both rooms and three ammunition recesses visible in a fourth room, accessed from the plotting room at the back of the AAOR. Inside the building was very wet and most of the woodwork rotten and beyond repair. Originally the walls were studded and covered in hardboard but most of this was found on the floor in a mushy state. With the exception of lighting fittings most of the electrical fittings, isolation switched and fuse boxes have survived on a panel in the plotting room.

The wooden plan of the surrounding gun sites has now been removed for safe keeping and restoration and there are plans to restore the AAOR at some time in the future and open it to the public but for now the building is without power and although much of the rubbish has been cleared away the rooms are still damp. The whole site is surrounded by a secure palisade fence.

The AAOR and its later replacement at Mistley controlled six heavy anti-aircraft batteries. Only one was emplaced with guns, the others being designated pre-surveyed sites. On declaration of an emergency mobile 3.7" guns would have been moved in along with Nissen huts for a control room and ammunition magazine; GPO and electricity cables were already in place.

The only fully fitted site was at Trimley Heath (HW2) at OS Grid Ref: TM275360 which was built between 1948 - 1950 and emplaced with four 5.25" guns. Today the site is virtually complete with control room, gun store, generator house, radar platform and the four gun pits three of which are filled in with rubbish.

The other five emplacements in the Harwich GDA were Royal Hospital (HW44) at TM161353, Shotley Street (HW44) at TM237345, Wix Abbey (HW46) at TM168292, Foulton Hall (HW47) at TM232285 and Walton Hall (HW48) at TM263243. These were all mobile sites and they have left no visible remains. When Mistley opened in 1953 the six sites were redesignated with a 6 prefix. E.g. HW45 became HW645.

All the sites were abandoned in 1956 on the abolition of Anti Aircraft Command.

Sources:

Bob Jenner
Keith Ward
Dave Wood, Landguard Fort Trust
Tom Barrett

Written by Graham White on 06 November 2022.

Is there good evidence that the backfilling of the Left Battery (eventually removed by English Heritage) took place in the 1950’s? I think it might, at least in part, have been after 1974. You might like to skip to paragraph 4 at this point… then come back to paras 2 & 3 for my involvement from the mid-1970s to the mid-1990s. By the time of EH’s archaeological investigation, my job no longer covered the Suffolk County Council’s interests at Landguard Point.

I worked for the newly created Suffolk County Council from 1974 to 2006. As a legacy from a pre-1974 agreement, parts of Landguard Common Site of Special Scientific Interest became the property of either SCC or the new district (Suffolk Coastal DC). In 1974/75 there was some anxiety by senior SCC officers not to accept the offer of the Right Battery (already a scheduled Ancient Monument) as part of the transfer of government land. The DOE then replaced the derelict military metal palisade fencing with concrete post and black chain mesh, to form an effective boundary between the Right Battery and what became SCC land. And - for the DC - a civil engineering contractor undertook earth-moving works to allow safe public access, with a view to its land being managed for informal recreation.
By 1976 I had become involved in the management of SCC’s 39 acres (to the south of the DC’s land) which became a Local Nature Reserve (formally declared under powers given by part of the National Parks and Access to the Countryside Act, 1949). It was agreed that the LNR would become land managed by Suffolk Wildlife Trust and this continued until, much later, Suffolk Wildlife Trust decided to withdraw from this. I understand that, after 2006, SCC’s LNR was passed to the district council (now “East Suffolk”).
Although this is circumstantial - and at best a minor footnote - I think that the DC’s mid-1970’s “civils” works (basically a tidying exercise) may well have extended to the dragline re-profiling of the rear of the Left Battery, which was then part of SCC’s land.