2.2 Mobilisation & Deployment - August 1939 to June 1940 2.2.1 Bristol Balloon Barrage On August 24th, a general mobilisation took place after which the balloon squadrons started leaving Pucklechurch to occupy their wartime sites, forming skeleton barrages around the vital port facilities at Avonmouth and Bristol. In the next few months, however, two of the squadrons were transferred to Eastern England where their services were more urgently required leaving only one to man both the both local barrages. Although a replacement unit was formed at Pucklechurch in December during the winter of 1939/40 balloon production was unable to keep pace with demand, so it was to be the end of March before the new unit, No.951 Squadron, was finally declared operational. 2.2.2 Heavy Anti-Aircraft Guns The heavy anti-aircraft guns had also moved to their war stations by early September 1939, and although initially operating from temporary sites, by late November were emplaced on permanent positions at Easton-in-Gordano, Portishead, Rockingham near Avonmouth, Cribbs Causeway, Brickfields at Winterbourne, and on Purdown. During the ensuing months the mobile guns were exchanged for statics and by the beginning of June 1940 four 3.7" weapons were in place on each of the sites providing the Bristol area with a total of 24 heavy anti-aircraft guns with which to counter the expected raids, far too few as it turned out for so important a target. 2.2.3 Light Anti-Aircraft Guns Following mobilisation light anti-aircraft guns were also set up at the Portishead Electricity Power Station, the Parnall Aircraft plant at Yate and the Bristol Aeroplane Company's premises at Filton. In addition heavy anti-aircraft and searchlight units also installed anti-aircraft machine guns around the local docks. In Bristol they were placed on the Wills Factory, Co-operative Wholesale Society Building, the Bonded Warehouses at Canon's Marsh and Cumberland Basin and on the Bristol Food Concerns premises, while at Avonmouth the guns were set up at the Smelting works. However, these were to be short term deployments, the guns all being removed by early 1940 when balloon barrages effectively covered these locations. Although the original plan had been to deploy searchlights at intervals of 3500 yards, due to a shortage of money at the outbreak of war only about half the equipment necessary had been delivered and these early shortages forced a 6000 yard spacing in many places. As a result by early October only 24 searchlights had been deployed in the Bristol Gun Defended Area, and it was to be June 1940 before anything approaching the full complement was in place. 2.2.4 Fighter Command The only local defenders to see any action during the 'Phoney War' were, not surprisingly, the RAF and their first chance came on November 10th 1939 when No.501 Squadron was 'Scrambled' in an unsuccessful attempt to intercept a German reconnaissance aircraft which was reported in the Gloucester area. This, however, was an isolated incident and as there was now more enemy activity over South Eastern England, the squadron, together with their Hurricanes, moved to that area soon after. Obsolete Gloster Gladiator biplane fighters replaced them, but No.263 Squadron only remained at Filton until April 22nd 1940 when they were dispatched to Norway. 2.2.5 Coastal Radar At this time enemy aircraft approaching Bristol would have first been detected by the single coastal radar station at Ventnor on the Isle of Wight. This was one of a small number of 'Chain Home', or CH, stations which were able to track aircraft approaching at altitudes of up to 15,000 feet at a range of 120 miles. The next CH station to be opened on the approach route to the city was at Worth Matravers, near Swanage, which came into operation in late May and this was followed later in the year by others along the South Devon coast. Also established were 'Chain Home Low' stations which were capable of detecting approaching raiders at altitudes of below 5000 feet at a maximum range of 50 miles. The first CHL in the West, also installed at Worth Matravers, came into operation in early June, to be followed by others sited in Devon and Cornwall. 2.2.6 Filton Balloon Barrage Sir Stanley White, the Managing Director of the Bristol Aeroplane Company, wrote to Fighter Command on May 27th requesting that a balloon barrage should be provided to protect the company's works at Filton, although he was well aware of the difficulties this might cause to any fighter aircraft operating from the nearby aerodrome. The response was rapid and two days later White was informed that he would get his balloons, No.935 Squadron moving immediately from Cardiff to Filton. From the end of May until late September, when a very damaging attack was carried out against the aircraft factories, only a few fighter squadrons were on short term deployment at Filton as the balloon barrage had made the airfield difficult to use as a fighter station by day, and impossible by night. 2.2.7 Western Expansion of Fighter Command: June 1940 Following the German invasion of France and the Low Countries on May 10th frantic efforts were made to spread the fighter defence westward, and the first new airfield to be occupied was Middle Wallop, in Hampshire. Lying some six miles south west of Andover it was ideally sited to intercept enemy aircraft approaching Bristol, and on June 1st the first Hurricanes from No.601 Squadron arrived, to be followed by the stop gap twin-engined Bristol Blenheim night fighters of No.236 Squadron in the middle of the month. Although some of these aircraft, modified bombers, were to be fitted with the new Airborne Interception radar, with a maximum range of about three miles, the equipment was still of relatively low performance and unreliable. In addition the Blenheim, which could only achieve a top speed of about 225 mph in its night fighter form proved quite inadequate to its task and the combination was to fail to bring any immediate increase in efficiency to the night defences. 2.2.8 Defenders in Action: June 1940 The Luftwaffe carried out its first raid on the Bristol area on the night of June 19th just as Filton, as Sector Station, had assumed temporary responsibility for three new fighter airfields which had received their first aircraft the previous day. A squadron of Hurricanes was sent to Exeter, while two squadrons of Spitfires were also deployed, one each at Pembrey, near Swansea, in South Wales, to cover the Bristol Channel and at St.Eval, near Newquay, in Cornwall. German bombers appeared over the area for the second time on the night of June 24th when a Blenheim from Middle Wallop became the first night fighter to operate, albeit unsuccessfully, in the defence of the West. Up until now cloud cover had prevented the local heavy anti-aircraft guns from going into action but two nights later the Cribbs heavy gun site became the first in the Bristol Gun Defended Area to fire in anger, expending two rounds just after midnight, during the course of a nuisance attack aimed at Avonmouth and Portishead Docks. 2.2.9 'Cats Eye' Night Fighters At this time resources were stretched to the limit, and in an effort to provide some additional form of protection the local day fighter squadrons were also instructed to provide aircraft to fly radarless 'Cats Eye' patrols at night. As a result, a small detachment of aircraft was sent each evening to Hullavington, in Wiltshire, a flying training station from which the first patrol by a single Spitfire was undertaken at the end of June. Despite the sterling efforts made by the pilots flying 'Cats Eye' sorties accidents were not uncommon, and to add to the problems the Hurricanes and Spitfires employed were virtually useless at night unless the target was silhouetted against cloud, so it was pure chance if the fighter was in the right place at the right time. NEXT