This is the start of a three part series, the story of two harbor defense organizations, how one, already at war, well trained and well armed, failed to stop a small force, while another, ostensibly at peace, facing a vastly stronger force, and in many ways poorly prepared, managed to stop their enemy.

I’ll put both stories in context, but what I found most interesting and most relevant to current Coast Guard missions was the means employed and the relative success of each in stopping a hostile ship from reaching its objective inside a port. The third part will talk about implications for the Coast Guard.

First, the St Nazaire raid. This is normally told from the prospective of the heroic British sailors and commandos who successfully ran a small ship (about the size of a 210) into the gates of the only dry dock on the Atlantic coast of occupied Europe where major German warships, including the Battleship Tirpitz, could be serviced. There the four and a half tons of explosive packed into the bow of the ship, exploded, wrecking the dry dock gates and disabling it for the remainder of the war.

The Target:

St. Nazaire, was a major German Navy operating base in occupied France, home for U-boats, mine sweepers, patrol vessels, and destroyers. From the Bay of Biscay it lay six miles up the Loire, and enjoyed the natural protection of shoals and mudflats with only a narrow dredged channel.

The Defense:

The Germans had 5000 troops in the immediate area. Defensive weapons included 28 coast defense and dual purpose guns ranging in size from 75 to 280 mm and  43 heavy machine guns 20-40 mm. The dedicated Coast Defense systems included two 280 mm (11″) guns, four 170 mm (6.7″), four 150 mm (5.9″), and twelve 75 mm (3″) in three batteries of four.

In the harbor there were a destroyer, an armed trawler, an armed merchant ship that functioned as a “guard ship,” four harbor defense boats, ten mine sweepers, two tankers, and several submarines.

The Attacking force:

The old destroyer Campbeltown was the center piece of the operation. She was the former USS Buchanan, one of 50 World War I vintage destroyers lend-leased to Britain by the US. Her role was to crash into the dry dock gates, discharge her commandos, scuttle herself to prevent the ship being moved, and after the crew had cleared, a four and a half ton explosive charge hidden behind concrete in her bow would be exploded by a time fuse.

Campbeltown, had the benefit of three weeks of hasty modification that was intended to:

• lighten the ship, so that she could exploit an unusually high tide to approach the harbor outside the normal dredged channel.
• disguise her appearance by making her look like a German  Raubvogel (German:”Bird of prey”) class torpedo boat (small destroyer),
• and to provide minimal protection for the bridge and the approximately 80 commandos she would be transporting.

Her torpedoes and 4″ guns were removed, and she was rearmed with light weapons: one 12 pounder (3″) and eight 20 mm machine guns. Light armor was applied to the wheelhouse and four armored bulwarks, one on each side and two more running longitudinally inboard, were erected on deck to protect the commandos who would lay prone on her decks during the approach.

She would be accompanied by 18 small craft: a 70 ft long motor torpedo boat, a motor gun boats, and 16 85 ton, 112 ft long 20 knot wooden hulled, gasoline powered motor launches with a 500 gallon auxiliary fuel tank fixed to the upper deck to increase their range. Of the 16 launches, four were equipped with two torpedoes each, the remaining twelve were intended to land commandos and upon completion of the operation, they were to pickup the commandos and the crew of the Campbeltown and return them to England. The twelve transport launches were armed with two 20 mm guns as well as rifle caliber machine guns.

The attack force totaled 622 men, including 265 commandos. The commandos were split into three groups, one on the Campbeltown and the other two distributed among two groups of motor launches. They were assigned to attack infrastructure targets in the port.

Timeline:

27 March at 07:20 the attack force, escorted by two small destroyers made contact with a surfaced U-boat, U-593. The U-boat submerged and successfully evaded the attacking destroyers. She would subsequently surface and report contact with destroyers, but apparently did not see the smaller vessels and indicated that the destroyers appeared to be departing the area, presumably after laying a minefield.

21:00 Attack force 65 miles from St Nazaire.

23:20 Air raid warning sounded. The intention was that the RAF would bomb the port during the attack to distract the gunners and force defenders into bomb shelters.

23:30 Bombing raid began. Because of cloud cover, only four aircraft bombed targets in St. Nazaire.

24:00 The unusual behavior of the bombers, remaining in the area and dropping only one bomb at a time, raised suspicion that a parachute assault was underway and a warning was issued.

28 March, 01:00 All guns ordered to cease firing and searchlights to be extinguished in case the bombers were using them to locate the port. Everyone was placed on a heightened state of alert. The harbor defense companies and ships’ crews were ordered out of the air raid shelters.

approx 0110 A Patrol vessel in the main channel reported suspicious vessels inbound.

0115 A lookout reported to the coast defense battery commander that unidentified vessels had been observed moving up the estuary. The coast defense commander ordered special attention be paid to the harbor approaches.

0122 Searchlights came on on both sides of the estuary highlighting the ships and a naval signal light  demanded identification. A convoluted response by a German speaking signalman on Cambeltown bought another 5 minutes and silenced the first battery that fired on the force.

01:28, The attack force was one mile from the dock gates. Fire was opened on the attacking force by all weapons that would bear. The attackers increased speed to 19 knots. The Campbeltown was being hit continuously.  During the run in, more than half the small vessels were destroyed before they reached their targets. In the confusion, shore batteries also fired on their own guardship.

01:34 Campbeltown rammed the dock gates. Commandos and crew debarked and scuttling charges were blown to keep the ship from being moved.

12:00 Campbeltown exploded destroying the dry dock gates, sinking two tankers, and killing 360 including an inspection party of 40 who were surveying the damage.

Of the 18 small vessels, only the Motor Gun Boat and five Motor launches survived the attack. Of the 622 who took part, only 228 men returned to England with the surviving vessels. Five escaped overland via Spain and Gibraltar. 169 men were killed (105 RN, 64 Commandos) and another 215 became prisoners of war (106 RN, 109 Commandos). Britain awarded 89 decorations for the raid including five Victoria Crosses (British equivalent of the Metal of Honor).

German photo taken before the explosion. HMS Campbeltown wedged in the dock gates. Note the exposed forward gun position on Campbeltown and the German anti-aircraft gun position on the roof of the building at the rear.

On-line sources are linked but I also use “Storming St. Nazaire,” by James G. Dorrian, US Naval Institute Press, 1998