U-Boats Off Our Coasts

On 15 May 1918, the combatant U-cruiser U-151, above, commenced operations off the Maryland coast. Almost unopposed, the U-151 sowed mines, cut two underseas communications cables, and sank 20 ships totaling over 50,000 gross tons. One of the few ships to survive a U-151 attack was the Edna, at top left, seen during salvage operations. Other U-boats that followed the U-151 into U. S. waters during the next few months were the U-156, U-140, U-117, U-155, and the U-152, at top. The U-151, U-152, and U-156 were Deutschland-type boats, and the U-155 was in fact the Deutschland, refitted with deck guns and torpedo tubes. The American tanker Frederick R. Kellogg, at right, was a victim of the U-117, but was later salvaged. The only U-boat to be lost from the group was the U-156, which struck a mine while attempting to transit the North Sea Mine Barrage after the war.

Over 150,000 tons of shipping were destroyed by U-boats off the American coasts during World War I. Although they occasionally torpedoed ships, the German submariners had little necessity for such action. Usually they would approach a ship on the surface, as at right, send over a boarding party, remove the crew, and sink the ship with delayed fuse demolition bombs. Ships refusing to surrender were usually sunk by gunfire. Although the U-boat campaign in American waters failed to stem the supply of men and materials to Europe, and was in that respect a failure, one important factor was apparent to U. S. and German strategists after the war. American ASW doctrine and capabilities in home waters were almost completely lacking.

On 11 December 1941, Germany declared war on the United States. The next day, Grand Admiral Erich Raeder and Hitler discussed Operation Paukenschlag (Roll on the Kettledrums), which would begin a month later, marking Germany’s first thrust into American waters since 1918. By January 1942, Germany had over 200 sub­marines, but long range boats for Operation Paukenschlag were scarce. Admiral Doenitz, in command of submarines, finally located five boats for the opening opera­tion. Mounting a deck gun and carrying some 14 torpedoes, each boat could operate in the Atlantic coastal shipping lanes for about two weeks. Successes were immediate and plentiful. By day the U-boats would lie on the bottom a few miles from the shipping lanes. When darkness fell they would surface and deliver attacks from sea­ward, their targets silhouetted against the glow of shore lights. The U-123, seen above during her commissioning on 30 May 1940, was the first U-boat into the coastal area; she sank nine ships totaling 52,586 tons.

The unidentified tanker, seen burning above, and the tanker Dixie Arrow, breaking up off Cape Hatteras, symbolize the heavy toll of Allied shipping during the early months of 1942. Losses in the Eastern Sea Frontier, extending from the Canadian border to Jacksonville, Florida, numbered nearly 500,000 tons by the end of April. As one group of U-boats left station another would replace it, with up to a dozen U-boats operating in the area at any one time. Initially, the Eastern Sea Frontier Command was almost helpless against the offensive. With many merchant ships moving independently, complete defensive coverage was impossible. A roving ASW destroyer patrol proved ineffective, due to the lack of proper equipment, training, or an established ASW doctrine. However, by April a "bucket brigade” system was put into effect for coastal shipping. Since most attacks were at night, merchantmen anchored each night in protected harbors situated a day’s steaming time apart, passing hunting areas like Cape Hatteras only by day.

In May 1942, an interlocking convoy system replaced the "bucket brigade” along the Atlantic coast, and merchant losses dropped dramatically. Admiral Doenitz had expected that U. S. defenses would tighten after his initial thrust and, when Atlantic coastal operations became difficult, U-boats were moved south into the Caribbean and Gulf areas. By this time, U-boat endurance had been extended by "milch cow” tanker submarines, from which the boats replaced expended torpedoes and took on fuel, as at right. Operations in the south were highly successful for a time, with merchant sinkings in Gulf waters for May, June, and July 1942 totaling over 375,000 tons. As the sinkings increased, however, the convoy system was extended and escort coverage increased. By the latter part of 1942, defenses had improved so much that most U-boats were shifted to the unprotected mid-Atlantic region. But the cost in Allied ships, men, and materials off our coasts had been high. Over 175 ships totaling 900,000 tons had been lost, and only six U-boats destroyed.

During 1943 and 1944, U-boats off the U. S. Coasts met with increasing resistance, and their kills diminished. The U. S. Tenth Fleet was formed in 1943, placing surface and air ASW units under one command. Convoys protected by a growing number of escorts left few easy targets. Radar-equipped patrol aircraft made even night opera­tions on the surface hazardous. The loss of a number of "milch cows” reduced the endurance of U-boats crossing the Atlantic. Above, the tanker submarine U-117 is almost completely engulfed in a depth bomb explosion, during an August 1943, aircraft attack off the Azores. Caught while attempting to refuel the U-66, alongside, the U-117 was destroyed. Homeward bound after sinking two ships in American waters, the U-66, escaped, but was lost less than a year later. At left, the U-134 survives an attack by a Bermuda-based aircraft in July 1943. A few days later the U-boat shot down an attacking blimp off Florida, and was in turn damaged by a patrol aircraft. The U-134, too, was subsequently lost off the coast of Europe.