Convoy PQ 16 (21–30 May 1942) was an Arctic convoy of British, United States and Allied ships from Iceland to Murmansk and Arkhangelsk in the Soviet Union during the Second World War. The convoy was the largest yet and was provided with a considerable number of escorts and submarines. Convoy QP 12, a return convoy, sailed on the same day.
As Operation Barbarossa, the German invasion of the Soviet Union, had failed in 1941, the Germans began to build up forces in Norway to intercept Arctic convoys with ships, aircraft and U-boats, rather than rely on a quick victory. (Air Fleet 5), the Luftwaffe force in Norway, was reinforced with bombers and torpedo-bombers in early 1942 and reorganised to attack convoys as they passed between the Norwegian coast and the ice of the Arctic, which was still close to its southern winter limit. The sun remained above the horizon at this time of year and the deck crews of the ships found the perpetual daylight fatiguing and stressful; glare from ice being particularly difficult for observers.
On 25 May air attacks began, the German bombers and torpedo-bombers co-ordinating their attacks. Torpedo-bombers launched at the same time in the Golden comb tactic to make it harder for ships to evade the torpedoes. The air attacks continued until 1 June and sank six ships, one other being lost to a U-boat; 3–6 German aircraft were shot down and one damaged; on 27 May 108 attacks by aircraft were counted.
After the convoy, the escort commander recommended that convoys be given far more anti-aircraft firepower and air cover from an escort carrier. The Germans claimed the virtual destruction of the convoy and concluded that air operations were more effective than submarine attacks in the long hours of daylight. The Golden comb tactic of combined dive-bombing and torpedo-bombing, with the torpedoes being dropped in a salvo, was vindicated.
Background
Lend-lease
After Operation Barbarossa, the German invasion of the USSR, began on 22 June 1941, the UK and USSR signed an agreement in July that they would "render each other assistance and support of all kinds in the present war against Hitlerite Germany". Before September 1941 the British had dispatched 450 aircraft, of rubber, 3,000,000 pairs of boots and stocks of tin, aluminium, jute, lead and wool. In September British and United States representatives travelled to Moscow to study Soviet requirements and their ability to meet them. The representatives of the three countries drew up a protocol in October 1941 to last until June 1942 and to agree new protocols to operate from 1 July to 30 June of each following year until the end of Lend-Lease. The protocol listed supplies, monthly rates of delivery and totals for the period.
The first protocol specified the supplies to be sent but not the ships to move them. The USSR turned out to lack the ships and escorts and the British and Americans, who had made a commitment to "help with the delivery", undertook to deliver the supplies for want of an alternative. The main Soviet need in 1941 was military equipment to replace losses because, at the time of the negotiations, two large aircraft factories were being moved east from Leningrad and two more from Ukraine. It would take at least eight months to resume production, until when, aircraft output would fall from 80 to 30 aircraft per day. Britain and the US undertook to send 400 aircraft a month, at a ratio of three bombers to one fighter (later reversed), 500 tanks a month and 300 Bren gun carriers. The Anglo-Americans also undertook to send of aluminium and 3, 862 machine tools, along with sundry raw materials, food and medical supplies.
Arctic Ocean
Between Greenland and Norway are some of the most stormy waters of the world's oceans, of water under gales full of snow, sleet and hail. Around the North Cape and the Barents Sea the sea temperature rarely rises about 4° Celsius and a man in the water would probably die unless rescued immediately. The cold water and air made spray freeze on the superstructure of ships, which had to be removed quickly to avoid the ship becoming top-heavy. The cold Arctic water was met by the Gulf Stream, warm water from the Gulf of Mexico, which became the North Atlantic Drift, arriving at the south-west of England the drift moves between Scotland and Iceland. North of Norway the drift splits.
A northern stream goes north of Bear Island to Svalbard and the southern stream following the coast of Murmansk into the Barents Sea. The mingling of cold Arctic water and warmer water of higher salinity generates thick banks of fog for convoys to hide in but the waters drastically reduced the effectiveness of ASDIC as U-boats moved in waters of differing temperatures and density. In winter, polar ice can form as far south as of the North Cape and in summer it can recede to Svalbard, forcing ships closer to Luftwaffe air bases or being able to sail further out to sea. The area is in perpetual darkness in winter and permanent daylight in the summer which makes air reconnaissance almost impossible or easy.
Arctic convoys
In October 1941, the Prime Minister, Winston Churchill, made a commitment to send a convoy to the Arctic ports of the USSR every ten days and to deliver a month from July 1942 to January 1943, followed by and another in excess of those already promised. The first convoy was due at Murmansk around 12 October and the next convoy was to depart Iceland on 22 October. A motley of British, Allied and neutral shipping loaded with military stores and raw materials for the Soviet war effort would be assembled at Hvalfjörður in Iceland, convenient for ships from both sides of the Atlantic. By late 1941, the convoy system used in the Atlantic had been established on the Arctic run; a convoy commodore ensured that the ships' masters and signals officers attended a briefing to make arrangements for the management of the convoy, which sailed in a formation of long rows of short columns. The commodore was usually a retired naval officer or a Royal Naval Reserveist and would be aboard one of the merchant ships (identified by a white pendant with a blue cross). The commodore was assisted by a Naval signals party of four men, who used lamps, semaphore flags and telescopes to pass signals in code.
In large convoys, the commodore was assisted by vice- and rear-commodores with whom he directed the speed, course and zig-zagging of the merchant ships and liaised with the escort commander. During the summer months, convoys went as far north as 75 N latitude then south into the Barents Sea and to the ports of Murmansk in the Kola Inlet and Arkhangelsk in the White Sea. In winter, due to the polar ice expanding southwards, the convoy route ran closer to Norway. Until early March 1942 one merchant ship of the 110 sent via the Arctic route had been lost; the condition of the receiving ports in the USSR caused more difficulty than German anti-convoy operations by ships, submarines and aircraft. As the summer season approached the hours of daylight increased just as the size of convoys got bigger to alleviate the accumulation of ships awaiting dispatch.
British grand strategy The growing German air strength in Norway and increasing losses to convoys and their escorts, particularly to convoys Convoy PQ 15 and Convoy QP 11, led Rear-Admiral Stuart Bonham Carter, commander of the 18th Cruiser Squadron, Admiral Sir John Tovey, Commander in Chief Home Fleet and Admiral Sir Dudley Pound the First Sea Lord, the professional head of the Royal Navy, unanimously to advocate the suspension of Arctic convoys during the summer months. The small number of Russian ships available for Arctic convoys, losses inflicted by based in Norway and the presence of the German battleship in Norway from early 1942, had led to a large number of ships full of supplies to Russia becoming stranded at the west end and empty and damaged ships waiting at the east end.
The loss of Trinidad in 14 May, concentrated minds in the British government and Admiralty about the feasibility of convoys during the summer months. With the loss of during the Battle of Crete in 1941, it was clear that even fast, manoeuvrable and well-armed warships were doomed, in waters where the Germans had air supremacy. Churchill wrote to Stalin that they had been lucky with Convoy PQ 15 and that the decision to sail Convoy PQ 16 with 35 ships. It was important that the Soviet air force made a maximum effort against airfields in northern Norway. Stalin replied that 20 bombers had been transferred to the north for attacks on German airfields and that with the navy the VVS "would do the utmost".
Despite the views of the Navy, pressure from the president of the United States, Franklin D. Roosevelt and the Soviet leader, Joseph Stalin, led to Churchill to bow to political reality,
and ordered on 20 May the dispatch of the convoy.
Signals intelligence
Bletchley Park
The British Government Code and Cypher School (GC&CS) based at Bletchley Park housed a small industry of code-breakers and traffic analysts. By June 1941, the German Enigma machine Home Waters () settings used by surface ships and U-boats could quickly be read. On 1 February 1942, the Enigma machines used in U-boats in the Atlantic and Mediterranean were changed but German ships and the U-boats in Arctic waters continued with the older (Hydra from 1942, Dolphin to the British). By mid-1941, British Y-stations were able to read Luftwaffe W/T transmissions and give advance warning of Luftwaffe operations.
In 1941, naval Headache personnel with receivers to eavesdrop on Luftwaffe wireless transmissions were embarked on warships and from May 1942, ships gained RAF Y computor (sic) parties, which sailed with cruiser admirals in command of convoy escorts, to interpret Luftwaffe W/T signals intercepted by the Headaches. The Admiralty sent details of Luftwaffe wireless frequencies, call signs and the daily local codes to the computors, which combined with their knowledge of Luftwaffe procedures, could glean fairly accurate details of German reconnaissance sorties. Sometimes computors predicted attacks twenty minutes before they were detected by radar.
B-Dienst
The rival German (, Observation Service) of the (MND, Naval Intelligence Service) had broken several Admiralty codes and cyphers by 1939, which were used to help Kriegsmarine ships elude British forces and provide opportunities for surprise attacks. From June to August 1940, six British submarines were sunk in the Skaggerak using information gleaned from British wireless signals. In 1941, read signals from the Commander in Chief Western Approaches informing convoys of areas patrolled by U-boats, enabling the submarines to move into "safe" zones. had broken Naval Cypher No 3 in February 1942 and by March was reading up to 80 per cent of the traffic, which continued until 15 December 1943. By coincidence, the British lost access to the Shark cypher and had no information to send in Cypher No 3 which might compromise Ultra. In early September, Finnish Radio Intelligence deciphered a Soviet Air Force transmission which divulged the convoy itinerary and forwarded it to the Germans.
Prelude