SM U-66 - Unrestricted Submarine Warfare

Unrestricted Submarine Warfare

From the early stages of the war the Royal Navy had blockaded Germany, preventing neutral shipping from reaching German ports. By the time of the so-called "turnip winter" of 1916–17, the blockade had severely limited imports of food and fuel into Germany. Among the results were an increase in infant mortality and as many as 700,000 deaths attributed to starvation or hypothermia during the war. With the blockade having such dire consequences, Kaiser Wilhelm II personally approved a resumption of unrestricted submarine warfare to begin on 1 February 1917 to help force the British to make peace. The new rules of engagement specified that no ship was to be left afloat.

U-66's first victim under the new rules was encountered on 1 March. The Norwegian steamer Gurre, reported as 1,733 tons, was crossing the North Sea while steaming from Narvik and Fredrikshald for Hull with a cargo of iron ore. U-66 torpedoed her at position 59°30′N 2°0′E / 59.500°N 2.000°E / 59.500; 2.000 (Gurre (ship)), sending down the Norwegian ship with 20 of her crew. The same day, U-66 encountered another Norwegian cargo ship, the 1,005-ton Livingstone, headed from Skien to Charente with a cargo of ammonium nitrate. Livingstone's cargo, used in the making of explosives and munitions, was too valuable to destroy. U-66's captain seized the ship as a prize east of Shetland. Further details of the encounter do not appear in sources, but it is known that the 11-year-old Livingstone not only survived the war, but remained in service under a variety of names until she was scrapped in 1962.

In late March, U-66 sank another two vessels. The 3,597-ton cargo ship Stuart Prince was headed from Manchester and Belfast to Alexandria with a general cargo when U-66 came upon her 85 nautical miles (157 km) off Broad Haven, County Mayo. U-66's torpedo attack was successful, sinking the ship and killing 20 men, including the ship's master. Five days later, U-66 encountered the five-masted bark Neath 28 nautical miles (52 km) south by east of Fastnet Rock. Equipped with an auxiliary triple-expansion steam engine, Neath was the former German bark R. C. Rickmers which had been seized by the Admiralty at Cardiff in August 1914. After U-66 torpedoed Neath at 08:45, the bark, en route from Martinique to Le Havre with a load of sugar, sank in seven minutes. The master of Neath was taken prisoner, but had been released and landed at Queenstown two days later.

During April 1917, German U-boats sank 860,334 tons of Allied and neutral shipping, a monthly total unsurpassed in either of the two world wars. U-66's sole contribution to this figure came when she torpedoed the tanker Powhatan 25 nautical miles (46 km) from North Rona in the Outer Hebrides. The 6,117-ton ship, which was carrying fuel oil from Sabine to Kirkwall, bested Margam Abbey as U-66's largest ship sunk when she went down with 36 of her crew. As was done with the master of Neath, Powhatan's master was taken prisoner aboard U-66.

Although the monthly total of tonnage sunk by all U-boats had peaked in April, the losses were over 600,000 tons in each of May and June. U-66 did not contribute to the May tally but, with her most successful month since April 1916, added to the June figures. On 5 June, U-66 torpedoed the 3,472-ton Italian steamer Amor which was on her way to Liverpool from Galveston; Amor sank approximately 200 nautical miles (370 km) from Fastnet Rock. The same day, Manchester Miller, a 4,234-ton steamer sailing from Philadelphia for Manchester with a load of cotton, was sunk about 10 nautical miles (19 km) away from Amor when she was hit by a torpedoes from U-66. Eight crewmen died in the attack; the survivors, who included three Americans, were landed on 9 June.

Two days after the attacks on Amor and Manchester Miller, U-66 attacked two more British steamers. The 4,329-ton Ikalis, carrying wheat from New York to Manchester, was torpedoed and sunk 170 nautical miles (310 km) from Fastnet Rock. The cargo ship Cranmore, of 3,157 tons, was headed to Manchester from Baltimore with a general cargo when torpedoed some 150 nautical miles (280 km) northwest of Fastnet. Though the ship was damaged, Cranmore's crew was able to beach her; the ship was later refloated and re-entered service.

U-66 sank her largest ship, the 6,583-ton British steamer Bay State on 10 June. The Warren Line cargo steamer had departed from Boston (the capital of Massachusetts nicknamed, coincidentally, the "Bay State") with a $2,000,000 war cargo destined for Liverpool. U-66 intercepted the ship 250 nautical miles (460 km) northwest of Fastnet and sank her, but there were no casualties among her crew of 45. Four days later, U-66 encountered the Norwegian bark Perfect, laden with grain, headed from Bahía Blanca for Copenhagen. Perfect, which had been built in 1877, was dispatched by U-66's deck gun at position 60°58′N 2°18′E / 60.967°N 2.300°E / 60.967; 2.300 (Perfect(ship)), east of Shetland.

On 17 June, Kapitänleutnant von Bothmer was replaced by Kapitänleutnant Gerhard Muhle as commander of the U-boat. U-66 was the first (and ultimately only) U-boat command for the 31-year-old Muhle, who had been a classmate of von Bothmer when both had joined the Kaiserliche Marine in April 1902. On 9 July, U-66 sank her first ship under her new commander, when she sent the Spanish steamer Iparraguirre to the bottom. The 1,161-ton steamer was headed to Santander from Piteå and Bergen with a cargo of pitwood, when U-66 attacked her west of the Orkney Islands.

U-66 scored another success when she torpedoed and sank the outbound British steamer African Prince on 21 July 60 nautical miles (110 km) north-northwest of Tory Island. The freighter—a Prince Line line-mate of Stuart Prince, sunk by U-66 in March—was carrying china clay from Liverpool to Newport News. The same day, U-66 also sank the 1,322-ton British sailing ship Harold about 5 nautical miles (9.3 km) from where African Prince went down. These two ships were the last sinkings credited to U-66. During six successful patrols, U-66 had sunk 24 ships and seized a 25th as a prize, for a combined total tonnage of 69,967.

U-66 began her seventh and what was to be her final patrol on the morning of 2 September when she departed from Emden destined for operations in the North Channel. Shortly after noon on 3 September, U-66 reported a position in the North Sea that placed her beyond known British minefields, in what was her last known contact. A postwar German study offered no explanation for U-66's loss. British records suggest that U-66 may have either struck a mine in an older minefield in the Dogger Bank area, or that a combination of destroyers, submarines, and anti-submarine net tenders sank U-66 sometime between 1 and 11 October. Author Dwight Messimer discounts this latter theory as not being supported by operational details.