2.8 Freedom from Attack - October 1942 to February 1944

2.8.1 4.5" Guns Arrive at Bristol: December 1942

Early December 1942 saw an exchange of 3.7" heavy guns for 4.5" guns between the Bristol and London areas, and this resulted in these weapons being installed, four each, at Pilning, Rockingham, Portbury and Lodge Farm. The 4.5" gun was a fairly simple weapon on a static mounting and was usually protected by an all-enveloping shield. Its rate of fire, eight 55 pound rounds per minute, was lower than the 3.7" and its muzzle velocity and effective ceiling of 26,000 feet only marginally higher.

2.8.2 Royal Observer Corps Reorganised: Mid-1943

In spite of the fact that by mid-1943 improved communications and the proliferation of radar equipment capable of tracking raiders over land had caused doubt as to the future of the Royal Observer Corps, it was decided that the traditional tasks they carried out were still of value to the air defence system, especially when the Groups were linked directly to their local GCI stations. A complete reorganisation and reappraisal of their duties was, however, carried out which resulted, in June, with the ROC taking over from Fighter Command the responsibility for issuing Air Raid Warnings. As men over 50 years of age were now considered too old to serve in the Control Centres, in Bristol their place was taken by young women and a move made from their cramped premises at Little King Street to a new and better equipped Control Centre at Clifton.

2.8.3 Searchlights Improved: Late 1943

During mid-August orders were issued to make additions to the searchlight layout in the Bristol Gun Defended Area in an attempt to improve the production of the constant and high degree of illumination required for gun engagement by 'seen' fire, as well as in the 'dazzle' or 'glare' rôle. Consequently, supplementary searchlights appeared on anti-aircraft gun positions, 'Z' sites and at, or near, unit headquarters or as satellites to existing searchlight stations.

2.8.4 More Bofors Guns made Available: August 1943

A further addition to the local anti-aircraft layout also came in August when the light anti-aircraft defences of RAF airfields were taken over by the RAF Regiment, thus releasing many 40 mm Bofors guns for deployment elsewhere. This resulted, the following month, in a number being sent to the heavy sites and 'Z' positions around Bristol and Weston super Mare.

2.8.5 Electronic Remote Control of Heavy Guns: Late 1943

Furthermore, during August the decision had been taken to re-deploy static and mobile guns to provide six-gun static sites suitable for conversion to Electrical Remote Control, starting with St.George's, Cribbs and Rodway, where electronic predictors were to eliminate the need for bearing and elevation positions to be manned. At about the same time the installation of the new and greatly improved microwave radar also went ahead at Westbury, Brickfields and Gordano, although in September the Avonmouth Smoke Screen became non-operational.