Operation Stonewall

Operation Stonewall was a World War II operation to intercept blockade runners off the west coast of France. It was an effective example of inter-service and inter-national co-operation.

Background
From the start of the war, the Allies had maintained a blockade against the import by Germany of seaborne goods. Although rich in many basic industrial materials, Germany, like Britain, could not produce some essentials. These included rubber, tin and tungsten.

Until the German invasion of the Soviet Union in June 1941 (Operation Barbarossa), the blockade was evaded via the Trans-Siberian Railway and large quantities of materials were shipped by this route. Once this was closed, German and Italian ships, stranded in Japan and Occupied Singapore, were used to bring in these essentials to ports in Occupied France. These were the blockade-runners.

Although an organised interdiction against these blockade-runners could not be set up until December 1943, several ships were intercepted and sunk in the Atlantic and Indian Oceans. Few actually managed successful runs.

The Operation
The New Zealand cruiser, HMNZS Gambia, joined the operation in December, 1943, and operated from Horta, in the Azores, with HMS Glasgow (C21), patrolling an area north of the islands.

On 23 December, aircraft from the American escort carrier USS Card (CVE-11) spotted a suspected runner and there were further reports of a flotilla of destroyers escorting another merchantman west from France. HMS Gambia,  Glasgow, and HMS Enterprise (D52) formed a cordon to intercept. Aircraft attacked the flotilla, now escorting an incoming merchantman (SS Osorno), reporting a hit and a near-miss on Osorno.

More warships (HMS Ariadne (M65) and HMS Penelope (97) and four Free French destroyers) joined the patrol to intercept another runner. Aircraft from RAF Coastal Command acted in close cooperation. Before the Allied ships and an RAF strike force could make contact, the shadowing bomber (crewed by No. 311 Squadron RAF - Czechoslovak) attacked with bombs and rockets and set the German ship—the SS Alsterufer—on fire. The German crew were rescued by four Canadian corvettes.

The German destroyers and torpedo boats had set out to meet and escort Alsterufer, in an operation codenamed Bernau, and now Glasgow and Enterprise sought to intercept them. Guided by shadowing aircraft, the cruisers intercepted eight destroyers in the early afternoon of 28 December and exchanged fire with them. Despite accurate German gunfire and torpedoes, effective German evading action and an attack with guided bombs by a Luftwaffe aircraft, the British ships maintained contact.

The German ships divided into two groups and the cruisers pursued one of these. By 16:00, two Elbing-class torpedo bosts (T25 and T26) and the Narvik-class destroyer Z27 had been sunk and one had escaped, damaged. About 62 survivors were picked up by British minesweepers, 168 by a small Irish steamer, the MV Kerlogue, and four by Spanish destroyers. The blockade runner Osorno reached the Gironde, but struck a wreck in the estuary. She was beached and subsequently unloaded offshore.

Glasgow, Enterprise and Ariadne returned to Plymouth and Penelope to Gibraltar. More blockade runners from the Far East were expected, so HMS Gambia and HMS Mauritius (80) maintained the cruiser patrol north of the Azores for the next three days. The Gambia then returned to Plymouth on 1 January 1944.

Three more German ships were sunk between 3 and 5 January by U.S. Navy patrols in the South Atlantic. These were the last runners.

By Autumn, German armies were retreating headlong out of France and the French ports were no longer open to Axis ships.

Allied participants

 * Ships: British, New Zealand, French, U.S., Canadian.
 * Aircraft: U.S., British, Czech