40th Light Anti-Aircraft Regiment, Royal Artillery

The 40th Light Anti-Aircraft Regiment, Royal Artillery, (40th LAA Rgt) was a Scottish air defence unit of Britain's Territorial Army (TA) during World War II. After serving with Anti-Aircraft Command in the defence of the UK, it joined 51st (Highland) Infantry Division and served with it at Alamein, in Tunisia and Sicily. It landed in Normandy on D + 1 and fought through the campaign in North West Europe, including the crossing of the Rhine, until VE Day. The regiment was reformed in the postwar TA but was amalgamated with other Scottish anti-aircraft units in 1950.

Origin The regiment was formed as part of the rapid expansion of Britain's anti-aircraft (AA) defences at the beginning of World War II. Regimental Headquarters (RHQ) was formed on 27 September 1939 at Inverness in Scotland (the last new TA LAA regiment), with 105 and 140 LAA Batteries under command, and the regiment received its number on 17 October. 105 LAA Battery had been formed in the Orkneys during the mobilisation of the TA on 25–27 August 1939, just before the outbreak of war. It had 283 and 284 Troops at Lyness and 285 and 286 Trps at Hatston. 140 LAA Battery was formed in Caithness at the same time as RHQ and included the existing 148 Independent LAA Trp, which had been formed by the TA at Invergordon Royal Navy Oil Depot on 17 January 1939 and was transferred from 14th (West Lothian, Royal Scots) LAA Rgt. The new regiment was completed on 10 November when 177 (Aberdeen) LAA Bty was formed at Aberdeen.Farndale, Annex M.Frederick, pp. 801–3, 811, 826.Litchfield, pp. 285–6.AA Command 3 September 1939 at Patriot files.

World War II

Battle of Britain and Blitz At the start of the war most LAA units were armed with Light machine guns (AALMGs), but the new Bofors 40 mm gun was on order. The units were deployed to defend vulnerable points (VPs) such as bridges, factories or airfields against low-flying or dive-bombing daylight raids, but could do little against high-flying or night raiders, such as the heavy night raid on Aberdeen on 12 July at the start of the Battle of Britain.Routledge, pp. 52–5.Collier, p. 163; Appendix IX.

40th LAA Regiment spent the whole of the Battle of Britain and the subsequent night Blitz on Britain's cities as part of 51st Light AA Brigade, covering North East Scotland in 3rd AA Division. The naval base at Invergordon was a particularly sensitive VP for this division.Farndale, Annex D.Routledge, Table LXV, p. 397.Order of Battle of Non-Field Force Units in the United Kingdom, Part 27: AA Command, 12 May 1941, The National Archives (TNA), Kew, file WO 212/79. However, NE Scotland received few attacks during this period.Collier, Appendix XXX.

The Blitz is considered to have ended in May 1941. 177 LAA Battery transferred to the newly formed 84th LAA Rgt at Glasgow on 23 August 1941 and was replaced on 4 September by 268 LAA Bty. This battery had been formed by 234th LAA Training Rgt at Carlisle on 12 June, based on a cadre of experienced officers and other ranks supplied by 40th LAA Rgt.Frederick, p. 834. 40th LAA Regiment remained in 51st AA Bde to the end of 1941.Order of Battle of Non-Field Force Units in the United Kingdom, Part 27: AA Command, 2 December 1941, with amendments, TNA file WO 212/80.

Overseas training 40th LAA Regiment was now selected for overseas service as a mobile unit and it left AA Command late in February 1942 (105 LAA Bty had already left in late December). Since few AA units had any experience or training for mobile warfare, it had been ordered in 1941 that any unit rostered for a mobile role overseas must first be withdrawn for training under War Office control in 11th AA Bde. The climax of this training was a full-scale test on an exercise under close scrutiny. Regiments that failed to meet the right standards were rejected and sent for retraining or the replacement of key personnel. 40th LAA Regiment passed through 11th AA Bde in April.Routledge, p. 76.Order of Battle of the Field Force in the United Kingdom, Part 3: Royal Artillery (Non-Divisional units), 2 April 1942, TNA file WO 212/515 .

On 1 May 1942 the regiment (with 105, 140 and 268 LAA Btys) joined 51st (Highland) Infantry Division (51st HD) and remained as the division's LAA component for the rest of the war. At the time 51st HD was under GHQ Home Forces, preparing for embarkation. It sailed on 16 June for the Middle East.Joslen, pp. 83–4.

The division landed in Egypt on 12 August, just after Gen Erwin Rommel's advance on Egypt had been halted at the First Battle of El Alamein. Although its arrival had been eagerly anticipated, the division was not yet desert-ready and was not immediately thrown into action: while the Battle of Alam el Halfa was fought parts of the division were guarding landing grounds in the rear areas. It joined Eighth Army on 10 September.Playfair, Vol III, pp. 363, 365, 387.Routledge, Table XXIII, p. 161. At this point the regiment was equipped with 48 Bofors guns.Joslen, p. 572.

Alamein Eighth Army was preparing for the Second Battle of El Alamein. Careful consideration was given to AA defence during the build-up. Instead of being deployed in circles round objectives, the LAA guns were sited on the attackers' likely lines of approach, where opening fire would not give away the presence of a likely target, and numerous dummy and alternatives positions were prepared. Within the divisions the control of LAA batteries was decentralised to brigade level, and a feature of the assault planning was the integration of the LAA guns into ground fire tasks in support of infantry and armour. When the initial artillery bombardment began on the night of 23 October, LAA batteries switched from defending the assembly areas to firing Tracer ammunition to mark the attacking units' boundaries in the dust and darkness.Routledge, pp. 155–6.

51st (H) Division's assault on 23 October ran into several centres of resistance and failed to take all its objectives. Over the following days the division worked to clear a way through the defences and minefields. On 2 November the division's renewed attack took its objectives and broke through. By late November Eighth Army was pursuing the beaten Axis forces to El Agheila.Playfair & Molony, Vol IV, pp. 38, 44–5, 48, 52, 70, 72, 74, 107, 221.

On 23 January 1941 troops of 51st HD were among the first into Tripoli.Playfair & Molony, Vol IV, p. 236. The division remained outside the city while Eighth Army probed forward to Tunisia; 40th LAA Rgt with 35 Bofors was loaned to 2 AA Bde in Tripoli for XXX Corps defence tasks.Routledge, Table XXIV, p. 162.

Tunisia By 25 February part of 51st HD had reached Medenine, preparing for the set-piece attack on the Mareth Line. On 6 March it was in defensive positions to fight off a poorly-conceived German attack. On 16/17 March it began attacks on the Mareth outposts, and once the New Zealand Division had outflanked the formidable position, 51st HD was on its way to Gabès on 29 March. The next Axis defence line was at Wadi Akarit. This time 51st HD took part in the main assault on 6 April, breaking through the minefields and anti-tank ditches. It then moved on to play a smaller role in the fighting at Enfidaville and the final advance on Tunis. During this campaign the Axis air forces had been active, though mostly against ports and airfields. Divisional LAA was usually deployed to protect the artillery. In the rough country of Tunisia, LAA units were often engaged in 'snap' actions against fast low-flying aircraft, usually coming out of the sun. The batteries tended to abandon the Kerrison Predictor (Predictor No. 3) and rely on the simple 'Stiffkey Stick' sight.Horrocks, pp. 148–55.Playfair & Molony, Vol IV, pp. 316, 325, 335, 353, 366–7, 372.Routledge, pp. 159–60, 182–3.

Sicily

51st (H) Division was designated for the assault landing in Sicily (Operation Husky) on 10 July 1943. 40th LAA Regiment's sea crossing was disrupted when the ships were attacked by U-boats and aircraft. Once ashore the divisional LAA regiments were assigned to beach defence, though they were hampered by the lack of a workable early-warning system. LAA batteries were reduced to firing prepared concentrations, either directional ('Curtains') or overhead ('Umbrellas'), which were ineffective and wasted scarce ammunition. However, the landings made good progress against negligible opposition, and 51st HD was well forward by nightfall. It was then directed to capture Palazzolo Acreide, which it achieved by the end of 12 July. The LAA unit handed over beach defence as the AA brigades began landing. 51st HD took Vizzini on the night of 14/15 July, and was then redirected towards the north east in a high-speed move to Paternò. However, resistance had stiffened, the division was unable to cross the River Simeto, and it had to fight hard to capture Gerbini Airfield. The division went onto the defensive on 21 July.Molony, Vol V, pp. 26, 61, 78, 82, 93, 106, 115–7.Routledge, pp. 259–63.

After Eighth Army had regrouped, 51st HD was employed in a thrust towards Adrano at the foot of Mount Etna, beginning with a crossing of the River Dittaino on the night of 31 July/1 August. It occupied Biancavilla on 6/7 August, when Adrano and Catania also fell. By 7 August (D + 28) 40 LAA Rgt was attached to 2 AA Bde, which was defending the airfields in the Plain of Catania. The Axis began withdrawing from Sicily on 11 August, and the campaign was over by 17 August.Molony, Vol V, pp. 150–2, 158–9, 174–5, 179–82.Routledge, p. 263, Table XLII, p. 267.

Overlord Training 51st (H) Division was among the formations selected to be withdrawn from the Mediterranean Theatre to return with XXX Corps to the UK to train for the Allied invasion of Normandy (Operation Overlord). It left Sicily on 7 November 1943 and landed in the UK on 26 November. It then began an extended period of re-equipment and training.Ellis, Normandy, p. 132.

On 14 March 1944 40th LAA Rgt's three batteries (105, 140 and 268) were augmented to a strength of four troops each when 51, 52 and 53 Trps joined from 235 LAA Bty of 62nd LAA Rgt, which had been broken up. This brought the establishment of Bofors guns up to 72, but before D-Day some LAA regiments began exchanging a proportion of their Bofors for multiple-barrelled 20 mm guns (usually Oerlikons or Polstens).Frederick, p. 830.Routledge, pp. 78, 306.

Normandy

51st (H) Division was a follow-up formation for Overlord, landing on Juno Beach on 7 June (D + 1). It did not complete its assembly until 10 June, but then moved into the bridgehead across the River Orne in preparation for an advance southwards. This bridgehead was under heavy air attack, and the Luftwaffe had developed a pattern of daylight attacks by fighters and fighter-bombers, flying low and using cloud and terrain for cover, before making diving attacks out of the sun. The 20 mm and 40 mm Troops of 40th LAA Rgt, together with 92nd (Loyals) and 4th Canadian LAA Rgts, were in constant daily action in the bridgehead, shooting down 17 enemy aircraft between them and driving off many other attacks.Ellis, Normandy, pp. 79, 173, 247.Routledge, pp. 313–4.

The division's attack out of the Orne bridgehead on 11 June came to nothing, but it continued to work its way down the east side of Caen, particularly on 23 June. An attack on the Colombelles factory area on 11 July ended in failure. On 18 July it cooperated on the flank of the armoured attack in Operation Goodwood.Buckley, pp. 64–5, 75–6, 98.Ellis, Normandy, pp. 248–50, 274–5, 343.