First patrol U-73 departed the
Helgoland (also known as Heligoland) for her first patrol on 8 February 1941. Her route took her the length of the
North Sea, through the 'gap' separating the
Faroe and
Shetland Islands, north-west toward
Iceland, then south and west. She sank the
Waynegate on 24 February 1941 south of Iceland. The boat arrived at
Lorient, on the French Atlantic coast, on 2 March.
Second patrol U-73 sank three ships on the same day, 3 April 1941. They were: the
Alderpool, the
Westpool and the
British Viscount, all in the vicinity of Iceland. Her next victim was on 20 April, southwest of
Rockall; also lost when this ship went down were two launches which were being carried as deck cargo:
ML-1003 and
M-1037.
Third, fourth and fifth patrols These sorties were conducted in mid-Atlantic but were uneventful. On 26 May 1941,
U-73 was ordered to help the wounded
German battleship Bismarck which was under attack from British destroyers. On the night of 26 May
U-73 spotted star shells that illuminated
Bismarck and also saw the
Bismarck firing her guns. But
U-73 was unable to attack the destroyers due to Force 7 to 9 winds.
U-73 reported the
Bismarcks position to Group West but the positions proved inaccurate.
U-73 then returned to port in France.
Sixth patrol U-73 entered the
Mediterranean Sea via the heavily defended
Straits of Gibraltar on 14 January 1942 during her sixth patrol. Rosenbaum claimed to have sunk a destroyer in February, but post-war records offer no confirmation. She docked at
La Spezia in Italy on 12 February.
Seventh patrol The submarine was attacked by a
Bristol Blenheim of
No. 203 Squadron RAF about north northwest of
Derna in
Libya on 22 March 1942. The damage was such that the boat was unable to dive and had to return to La Spezia on 26 March 1942. The U-boat was under repair at La Spezia for four months.
Eighth patrol On 11 August 1942 she sank the aircraft carrier during
Operation Pedestal (supplying
Malta). Rosenbaum was awarded the
Knight's Cross and sent to command the
Black Sea U-boat flotilla. He was the son of German-American parents living in Chicago
U-73 was depth-charged during an unsuccessful attack on
Operation Torch (the invasion of French North Africa) troopships on 7 November. On 10 November,
U-73 missed the battleship with four torpedoes launched at a range of five kilometers. She also damaged the
Lalande off
Oran on 14 November 1942. This ship was under repair until June 1943.
Tenth and eleventh patrols U-73 was damaged in an air attack on 5 December 1942 and forced to return to base. The boat was also attacked by a British
Lockheed Hudson of
500 Squadron on 27 December 1942; damage was slight – the Hudson was shot down. She sank the 7,200-ton American
Liberty ship SS
Arthur Middleton from the convoy
UGS 3 on 1 January 1943 off Oran.
12th patrol As allied forces prepared for
Operation Husky (the invasion of Sicily),
U-73 sank the 1,600-ton British freighter
Brinkburn off Oran on 21 June 1943 and damaged the 8,300-ton Royal Navy oiler on 28 June 1943. The
Brinkburn exploded with such force that damaged food cans and two 75 mm shells, still in their transit boxes, were found on the U-boat's bridge. The boat tied up at
Toulon in France on 1 July 1943.
13th patrol Patrol number thirteen took
U-73 to
Sicily; she reached the
Straits of Messina (between the island and the Italian mainland), on 19 August 1943.
14th patrol U-73 was attacked by the British submarine south-east of Toulon on 30 October 1943 (just before the end of her patrol). The
torpedo missed.
15th patrol and loss U-73 found the convoy
GUS-24 off Oran on 16 December 1943 and torpedoed the 7,200-ton American Liberty ship SS
John S. Copley. As the damaged vessel returned to port, the destroyers , and left
Mers-el-Kebir to find the U-boat. Hull turbulence made the U-boat's
hydrophones ineffective at the speed
U-73 was leaving the area, so she was unaware of the destroyers until
Woolseys pattern of depth charges exploded below the submarine at 18:39. Sea water poured in between the bow torpedo tubes and from a salt water inlet valve for the diesel engine cooling system. She sank by the stern following a brief exchange of gunfire, 34 of the crew were rescued by 22:10. and sixteen of the U-boat crew perished.
Wolfpacks U-73 took part in five
wolfpacks, namely: •
West (31 May – 16 June 1941) • Kurfürst (16 – 20 June 1941) • Grönland (12 – 27 August 1941) • Reissewolf (21 – 31 October 1941) • Wal (10 – 15 November 1942) ==Summary of raiding history==