At the outbreak of War the only HAA Guns defending Suffolk were located in the Harwich Gun Defended Area (GDA). The role of these guns was to defend Harwich Harbour as well as the forward Martlesham aerodrome.
The Harwich GDA static sites had been completed by early 1940. Additional sites were established by bringing in mobile guns e.g. three mobile 3” guns arrived for site H4 on June 14th. The Harwich Guns were first in action on June 18th from 2310 hrs to 0040 hrs when sites H1,H2,H3,G4, H9, H10 and H12 fired at single bombers illuminated by searchlights.
By 1941 Lowestoft, which was included in the Yarmouth GDA, had been provided with two HAA gun sites each with four 3.7” mobile guns (later replaced with statics). Yarmouth and Lowestoft had been relatively unaffected by bombing during 1940 – the large increase in the number of raids during 1941 was considered likely to be due to enemy aircraft having shipping as a prime target and Yarmouth was the obvious place to intercept convoys; if they failed to locate convoys it was reasoned they dropped their bombs on Yarmouth and Lowestoft instead. Due to the increased number of raids, during November 1941 four 3” guns were to be withdrawn from aerodrome defence (two from Feltwell and two from the Norwich site H1) to be redeployed to Lowestoft where it was considered they could be more effective. The four guns were to be established at a new site (LH3). Yarmouth also received an additional four 3” mobile guns.The continued Enemy air activity during 1942 in the Yarmouth GDA gave the chance for 2 AA Division (whose area included the Yarmouth GDA) to give all mixed HAA batteries in the Corby and Derby / Notts GDA’s a chance to engage the enemy by deploying for a while in the Yarmouth GDA, as the first half of 1942 had been relatively quite in the rest of 2 AA Division’s area.
Table showing location of HAA Gun sites in Harwich GDA and Yarmouth GDA - July 1940 and July 1941
Right: Map showing HAA sites in Harwich GDA and
Yarmouth GDA in 1940 and 1941
The typical layout for a static site was four guns arranged in a ‘bow’ – the two central guns slightly forward and those on the flanks slightly to the rear. This was to allow engagements on a flank without firing over the adjacent crew.
Right - aerial photo of LH1 in 1945
and plan of LH1. The gun pits laid
out in a 'bow' can clearly be seen.
Gun pits went through a series of designs from the pre-war design of a simple pit with six lockers for ammunition arranged around the gun holdfast to designs which eventually incorporated crew shelters. Mobile gun sites were laid out in a similar bow pattern although there apparently was a great variation in the design of gun pits prepared. In May 1942 6 AA Division issued instructions for gun pits to be laid out on a uniform basis and issued plans for the construction of ammunition recesses.
Above: Top Left - 1938 standard design for 3.7" Static Gun Pit. Bottom Left - 1941 standard design for 3.7" Static Gun Pit with crew
shelters now added. Right - 6AA Div 1942 standard design for Ammunition recess in 3.7" Mobile Gun Pit
Posts for Fire Command, Predictors, Range Finding equipment etc where at first often housed in separate sandbagged emplacements but in 1941 a standard Command Post design built from brick and concrete was issued. Accommodation for the battery personnel was mostly in huts although mobile locations often had to put up with tents.
Right: Layout of the 1941 standard
Each HAA battery was also protected by LAA guns in case of low level attack. For example on Oct 27th 1940, Lewis guns of H12 scored hits on a Dornier 17 attacking at approximately 300 ft. On Jan 4th 1941 Gunner S.A.J Martin of 302 AA Bty at Ipswich (H12) won the Military Medal by remaining calm at the light machine gun post while three Dornier’ s attacked with cannon and machine gun at 100 ft, perforating sandbag emplacements, tents and huts. He withheld his fire until one aircraft was quite close and then hit it with a full drum causing it to crash in the River Stour.
Guns were constantly being shifted from location to location to meet needs as they arose and new sites established – e.g. two mobile 3.7” guns arrived at a new site at Old Felixstowe (H7) during March 1942. Dobinson (2001) recorded a total of 18 HAA sites in Suffolk. Some were certainly only occupied for a short duration or perhaps never even armed (e.g. site LH4 and LH5 in Lowestoft (Yarmouth GDA)). Mobile 3.7” HAA guns were always in short supply and many mobile guns were eventually replaced by static 3.7” guns. As already mentioned above the mobile guns in the Yarmouth GDA were replaced with statics. In October 1942 the mobile guns at H2 (Trimley) were finally replaced with statics and at H4 (Shotley Street) four static 3.7” guns replaced the four mobile 3” guns, which moved to H7 (Old Felixstowe) to relieve the four mobile 3.7” guns at this site.
AA Command, C Dobinson, Methuen, 2001
6AA Div papers, TNA
2 AA Div papers, TNA
99 HAA Regt papers, TNA