Stretching from the moment German forces attacked Poland on September 1, 1939 until the final day of the war in May 1945, the battle for supremacy on the high seas in the North Atlantic was one initially fraught with doubt among the Allies. During the early stages of the war, Nazi Germany’s Kriegsmarine masterfully devised a plan to thwart Allied shipping, deftly maneuvering its powerful U-boat fleet to harass merchant ships destined for the United Kingdom.
A crucial lifeline, only aid from the U.S. would be adequate to sustain the British Empire during some of the darkest days following the German conquest of France and the Low countries.
In addition to Germany’s U-boat fleet a persistent dagger held against the throat of Allied shipping, German surface ships preyed on Allied shipping and provided a security blanket for U-boats lying in wait beneath the surface. Although the Bismarck had been sent to the bottom in May 1941, a constant threat to Allied shipping remained from Tirpitz, Lützow, Admiral Scheer, Gneisenau and Scharnhorst, all of which menaced Allied the North Atlantic shipping lines. Sheltered in Norwegian waters, Tirpitz was the paramount concern for the Royal Navy. At a cost of 501 merchant ships lost, estimated at 2,209,507 tons in 1941 alone, a desperate Royal Navy embarked on an audacious plan to inflict a crippling blow on German naval capabilities in the North Atlantic and, perhaps, permanently tip the strategic balance in the Allies’ favor.
Such a daring plan faced significant hurdles: The Normandie dock rests at St. Nazaire, six miles inside the estuary of the Loire River; the estuary was often too shallow for larger ships to enter; and the dock itself was heavily defended by over 5,000 German troops.
Realizing a Royal Air Force aerial attack or a Royal Navy bombardment lacked the precision necessary to put the dry dock out of service and intending to minimize civilian casualties, British Combined Operation Headquarters resolved to move forward with a plan to dispatch a destroyer packed with 4.5 tons of high explosives settled in concrete to ram the 35-foot-high caissons which protected the Normandie dry dock.
Should the Normandie dry dock be put out of action, German warships would not have an Atlantic coast base from which to operate, or re-fit or repair its vessels.
For the mission, the RMS Campbeltown was chosen. A former U.S. Navy destroyer traded to the UK under terms of the 1940 Destroyers for Bases agreement, Campbeltown was stripped of defensive armament and modified to appear as if it were a German destroyer.
Aided by unusually high tides in the spring of 1942 and traveling under cover of the night, Campbeltown would be accompanied by two Hunt Class destroyers, a Motor Torpedo Boat unit, a Motor Gun Boat unit, four motor launches armed with torpedoes and 12 Fairmile B motor launches to ferry commandos tasked with secondary acts of sabotage around the port.
Launching Falmouth, Cornwall the afternoon of March 26, the task force rounded the British Isles and headed into the open sea, reaching a point 75 miles off the coast of St. Nazaire at 9 p.m. on 27 March. Creeping up on the port under darkness with 192 raiders from the Special Service Brigade supported by 92 additional commandos, the attackers were joined by several RAF aircraft on a diversionary bombing run.
As the force approached the estuary just after 1 a.m. on the 28th, German security lights activated and demanded identification. Still flying a German flag, Campbeltown responded it had been fired upon by “friendly” forces. As the gunfire briefly silenced, the crew of the Campbeltown lowered the German flag and replaced it with the White Ensign of the British Navy. Travelling at 19 knots, the Campbeltown ripped through torpedo nets and smashed into the thick caissons protecting the dry dock, hurtling through the wall and finally coming to rest some twenty feet inside the dock just after 1:30 a.m.
Despite German shore batteries inflicting heavy casualties on British raiders, some 100 commandos disembarked and spread havoc, destroying gun emplacements and naval stores. For the next five hours, commandos busied themselves engaging with German forces and demolition teams scattering around the port planting charges on vital pump houses and winch houses, patiently waiting for the charges in Campbeltown to erupt.
Hours into the raid, near dawn, realizing a withdrawal of the raiding party with the assistance from the Royal Navy was virtually impossible and with Royal Navy ships retreating under heavy German fire, the commander on the spot, Lieutenant Colonel Augustus Charles Newman, ordered his men to fight until ammunition was exhausted and make every attempt to return to England by any means necessary. Still in the fight with men scattered all over the German base, Newman collected stragglers and fought into St. Nazaire and eventually surrendered. Five men miraculously made their way to neutral Spain, but 215 British commandos were marched into captivity.
Unfortunately, the British raiders were never able to see the result of their handiwork: Around noon on the 28th, the Campbeltown burst in a fiery explosion. Thinking the ship safe for inspection, 40 Germans onboard and another estimated 300 milling around the ship were killed in the blast.
Although the raid claimed the lives of 169 British military personnel, the mission was an unqualified success: Completely disabled by the raid, the Normandie dock was rendered useless to German naval vessels for the duration of the war.
The Normandie dry dock would not reach full operation to service ships until after 1950, five years after the war ended.