The U-Boat Assault on America's Home Waters, Part I

U-boat Attack

From Monitor the Journal of the National Marine Sanctuaries 

Our readers are probably familiar with the German U-boat attacks off the Atlantic Coast when they turned Cape Hatteras, known as "Torpedo Alley" into a shooting gallery. The U-boats sank 397 ships (a large portion in 1942) with the loss of only three of their submarines. Like many aspects of the Second World War, however, the precedent for this had been established in the previous war, when Germany discovered the "target rich" environment at the crossroads of Atlantic shipping lanes off the North Carolina Coast. 

After America's declaration of war, German U-boats became a serious threat to merchant and naval shipping along the U.S. East Coast. U.S. resources were devoted elsewhere as the Navy focused on sending vast manpower, supplies, and naval forces to Europe. It became difficult to provide an adequate defense against submarine attacks close to the homeland, leaving shipping traffic in U.S. waters vulnerable from April 1917 until the war's end in November 1918. During this period, four U-boats (U-151, U-156, U-140, and U-117) voyaged across the Atlantic and attacked vessels in U.S. waters. Three of them, U-151, U-140, and U-117, sank a total of 10 vessels off North Carolina’s coast. 

U-151 

U-151 in European Waters

The arrival of U-151 off the U.S. East Coast in May 1918 made it the first foreign enemy naval vessel to invade U.S. waters since the War of 1812. The German U-boat’s initial actions included cutting undersea communication cables near the port of New York, laying mines off Long Island and the entrances to Delaware Bay and Chesapeake Bay, and sinking three schooners off Virginia. Afterwards, U-151 went on to sink and damage additional vessels off the coasts of North Carolina and New Jersey. 

U-151’s warfare activities off North Carolina began on June 5, 1918, when it sighted the British steamer Harpathian with 40 men onboard and westward bound from London, England to Newport News, Virginia. The steamer was approximately 90 miles southeast of Cape Henry and directly east of Knotts Island, North Carolina, when U-151 torpedoed the unarmed vessel. Harpathian sank seven minutes later without loss of life. U-151 struck again nine hours later, some 50 miles east of the Harpathian, when it sank the Norwegian steamer Vinland, en route from Cuba to New York with a cargo of sugar. 

Three days later on June 8, U-151 captured the Norwegian freighter Vindeggen, a vessel of 3,179 gross tons, en route from Chile to New York with a cargo of copper ingots, wool, and salted skins. U-151 quickly realized the wealth Vindeggen was carrying and set about transferring as much copper as possible to the U-boat. Two hours after capturing Vindeggen, the American steamer Pinar Del Rio, on its way to Boston with sugar from Cuba, came upon the scene and was quickly shelled by U-151, sinking it 80 miles northeast of Nags Head, North Carolina, without loss of life. After transferring a portion of Vindeggen’s copper cargo to the U-boat, U-151 sank the freighter on June 10. Later that day, U-151 continued its attacks by sinking the Norwegian steamer Hendrik Lund. Hendrik Lund was carrying general cargo and coal when it sank approximately 240 miles offshore of the Virginia-North Carolina border. U-151 continued its patrol and moved north before returning to Germany in July 1918. In total, U-151 sank 23 ships in the western Atlantic during its 94-day voyage from Germany to the U.S. East Coast and back. U-151 was surrendered to France at wars end and was eventually sunk as target ship at Cherbourg, 7 June 1921. 

Admiral Tirpitz Flying the Flag of  "Kultur" and "Frightfulness" Attacking America

With the German U-boat threat now in United States home waters, the U.S. military dispatched naval ships and pressed a number of smaller vessels, such as yachts, fishing boats, and powerboats, into action as sub chasers and minesweepers. Other anti-submarine measures included using aircraft for aerial anti-submarine patrols and the placement of large submerged nets outside harbors to stop U-boats from entering. These efforts were partially successful against Germany's 1918 U-boat campaign in U.S. waters, and provided a valuable learning experience that helped later in combating the enemy U-boat threat during World War II. 

U-140 

Following U-151’s departure, the next German U-boat to prowl the North Carolina coast was U-140, under the command of Korvettenkapitan Waldemar Kophamel. U-140 was a new, heavily armed U-boat cruiser, launched on November 4, 1917, and was larger and more modern than U-151. It was 296 feet long with a cruising speed of 15 knots on the surface, and eight knots while submerged. Its armament consisted of two deck guns, four bow torpedo tubes, and two stern torpedo tubes. 

U-140 reached the coastal waters off North America, just south of Newfoundland, on July 26, 1918, and opened its campaign with a running gun battle with the 13,967-ton British steamer SS Melitia. The merchant vessel was too fast for U-140 and gradually outpaced the U-boat and escaped. That evening, U-140 engaged another British ship, the 4,147-ton SS British Major, in a surface gun battle. The U-boat was able to slowly close the distance between the two vessels but the gathering darkness forced it to break off the action before it was able to get within the enemy's range. The next day, however, the U-boat scored its first victory. Just south of Halifax, Nova Scotia, it stopped the Portuguese bark, Porto, carrying a cargo of lumber. In order to save ammunition and torpedoes for more valuable and dangerous game, U-140's boarding party placed explosive charges at strategic points in the ship and exploded them to sink the vessel. The next day, difficulties controlling U-140’s depth in heavy seas spoiled an attempted submerged attack on SS Kermanshah, a 4,948-ton American cargo ship. These same heavy seas also precluded any attempt at pursuit and Kermanshah escaped without harm. 

U-140 Underway to Internment

The first week in August brought U-140 a series of victories. On August 1, some 200 miles off New York, U-140 made a submerged attack on the 7,029-ton Japanese ship SS Tokuyama Maru and scored a torpedo hit. When the torpedo explosion proved to be less than fatal, U-140 surfaced to deliver the final blow with its deck guns. 

On August 4, U-140 attacked the American tanker O.B. Jennings some 115 miles southeast of Cape Henry, Virginia. The U-boat attempted a submerged torpedo shot at the tanker, but it was unsuccessful and had to surface to bring its 5.9-inch guns to bear. For 22 minutes, O.B. Jennings fought back bravely with its own 4.7-inch gun, but a shell from U-140 hit O.B. Jennings’ ammunition magazine, putting its gun out of action. At that point, O.B. Jennings' crew abandoned ship, and the U-boat closed range and sank the vessel. 

U-140 then turned its attention to the crew adrift in the lifeboats. U-140’s commanding officer interrogated the crew members, took O. B. Jennings' second officer prisoner, and then cleared the area. U-140 then navigated southward and on August 5, sank the American four-masted coal schooner, Stanley M. Seaman, 128 miles off Cape Hatteras. Stanley M. Seaman was headed from Newport News, Virginia, to the Dominican Republic when the U-boat fired a warning shot at the ship's rigging. The crew scrambled quickly into their yawl boat without bringing supplies. When Captain Kophamel learned of the crew's situation, he allowed them to return to Stanley M. Seaman to collect provisions. Men from the U-140 then boarded and sank the vessel with explosive charges. 

Part II of this article will be presented in tomorrow's issue of Roads to the Great War, "The U-Boat Assault on America's Home Waters"  Thanks to Steve Miller for bringing this material to our attention.