Operation CROSSBOW

In May 1942, over Peenemünde in north eastern Germany, a reconnaissance Spitfire flown by Flt Lt Donald Steventon diverted from his main target and captured images of an airfield with three concrete-and-earth circles.

Thought to be insignificant, the images actually showed the Axis Vergeltungswaffe Weapon programme (more commonly known as the ‘V weapons’). This programme would bring about the creation of the world’s first operational cruise missile (V-1) and ballistic missile (V-2), the use of both of these weapons would lead to over 8000 fatalities and 20,000 serious injuries from June 1944 to March 1945.
British intelligence had begun to receive reports of the Axis developing a pilotless aircraft and rocket-based artillery from November 1939; however, the characteristics of the V-weapons remained a mystery. In January 1943, the Photographic Reconnaissance Unit (PRU) based out of RAF Medmenham were tasked with obtaining more photographs of the Peenemünde site with two later flights over the site gathering evidence of several large buildings and a powerplant that had been constructed.
Initially, due to heavy bias from some senior British scientific advisors, there was much scepticism if the Axis had the capability, or that it was even physically possible to develop such weapons. By 15 April 1943 both the Secret Intelligence Service and the Combined Detailed Interrogation Centre had conducted a joint investigation under the codename BODYLINE. Given the highest priority by the end of April, four sorties had been conducted over the Peenemünde site and detailed analysis of the photographs had revealed significant evidence of structures common with the production of explosives: towers and cranes, plus elliptical and circular emplacements which could not yet be explained. Further flights revealed the movement of cylindrical objects via road and rail, a large tower roughly 40 ft tall with a cylindrical object roughly 35 ft tall attached to it; and finally, on 28 June 1943 two objects were identified, roughly 38 ft long, 6 ft in diameter with a tail and three fins. There was now no doubt that the Axis had developed long-range rockets.
Op BODYLINE would now focus on determining some of the details of the Axis rocket plan and the PRU was tasked with finding potential launch sites within northern France based within 130 air miles of London (the range of the missiles gained through leaked documents). By 29 June 1943 the UK Defence Committee decided the best defence against these weapons was to strike Peenemünde with a night bombing raid as soon as possible, as well as to continue reconnaissance missions over northern France and prepare to strike any installations found. The first established launch site was identified in August 1943 when activity was identified at Watten, near St. Omer. At the same time, Bomber Command proceeded with planning the Peenemünde raid (called Op HYDRA) and photo reconnaissance flights over the facility showed a number of rail lines and huge underground bunkers under construction. By September 1943 raids had been conducted on both sites and although bombing was not as accurate as would have been ideal, these raids delayed the V-Weapon programme by what is estimated to be two crucial months.
On 15 November 1943 the codename of the operation was changed from BODYLINE to CROSSBOW. Operation CROSSBOW continued aerial reconnaissance of northern France and by the third week of December 1943, 75 initial ski sites were identified which would be used for launching V1 “Buzz Bombs” against the south coast of England. All of the sites followed the same blueprint known as the ‘Bois Carre’ layout, named after the first site discovered. There were three ski shaped buildings, a launch ramp angled up 10 degrees and 125 ft long (always on a direct bearing to London) and a launch control building always near the left foot of the ramp. In the 48 hrs preceding this realisation, the final 21 ski sites were identified (96 ski sites in total: 6 squadrons of 16 sites each, a standard Luftwaffe ORBAT).

From December 1943, Bomber Command asked the United States Air Force (USAF) to help with bombing raids against these ski sites and from 1944 the raids were focused on suspected sites in France in preparation for Operation OVERLORD, to prevent their use against the Allies conglomerated on the South Coast. By March, all 96 sites had been bombed.
Realising that the launch sites were heavily recognisable, the Axis modified the sites into much simpler layouts, known as ‘Belhamelin’ layout (again named after the first found) with most of the buildings now resembling farm buildings. These buildings were all prefabricated and could be disassembled shortly before the launch of a weapon. Disguised as farms and hidden within woods meant that these sites could not be easily identified and then bombed, and it is from these sites that V-1s would be launched towards London.
Following D-Day, the focus moved to V-1 sites and supply points; however, as Allied troops advanced and overran the sites closer to the UK, they forced the Axis further inland and out of the important 130 mile radius. Each ski site was intended to launch 2000 V-1s every 24 hrs but the most that were launched in one 24 hr period was 300 across all sites. Only approximately 100 of them hit their target of London. By September 1944, the focus was placed on airfields with Axis bombers capable of delivering air launched V-1s and suspected V-2 production plants. By February 1945, with the imminent defeat of the Axis, the Allies decided that if any V-Weapons remained, the Axis would be unable to deploy them before the end of the war. Operation CROSSBOW had been effective.
Fast forward to 2021 and Crossbow Flt, as part of 1 ISR Sqn, continues Operation CROSSBOW’s legacy by analysing imagery collected by military aircraft in support of operations. Crossbow Flt analysts, much like the analysts of Operations BODYLINE and CROSSBOW, monitor key locations detecting and analysing changes as they happen – much like was done at Medmenham in WW2, although they smoke a lot less in the office now! Advances in technology mean that Crossbow Flt analysts are able to view and analyse imagery in near-real-time from RAF Wyton. The analysts process (P) and exploit (E) the imagery before they disseminate (D) their analysis to commanders who utilise the intelligence to inform their decisions and shape operations, a process known today as PED. As part of a coalition network, Crossbow Flt continues the close working relationship between the RAF and the USAF, providing PED of Full Motion Video (FMV) in support of USAF intelligence missions, as well as those of UK Defence.