German submarine U-573

German submarine U-573 was a Type VIIC U-boat built for the Nazi German Kriegsmarine for service during World War II.

Her keel was laid down 8 June 1940 at the Blohm + Voss yard in Hamburg as 'werk' 549. She was launched on 17 April 1941 and commissioned on 5 June with Kapitänleutnant Heinrich Heinsohn (12 February 1910 – 6 May 1943) in command. Heinsohn commanded her for her entire career in the Kriegsmarine. In May 1941 he had arranged that the city of Landeck in Tyrol adopted the submarine within the then popular sponsorship programme (Patenschaftsprogramm), organising gifts and holidays for the crew, earning her the honorary name U-573 Landeck.

The boat began her service career as part of the 3rd U-boat Flotilla when she conducted training; on 1 September 1941 she commenced operations with that flotilla. She was transferred to the 29th flotilla, also for operations, on 1 January 1942.

Operational career
U-573 conducted four war patrols, sinking just one ship.

1st, 2nd and 3rd patrols
Her operational career began with her departure from Kiel on 15 September 1941. She entered the Atlantic via the North Sea and the gap between Iceland and the Faroe Islands. She almost reached the Labrador coast before heading for St. Nazaire in occupied France, docking on 15 November.

U-573's second patrol involved the boat slipping past the heavily defended Strait of Gibraltar into the Mediterranean, where she sank the Norwegian Hellen (5,289 tons) with two torpedoes on 21 December 1941. She arrived at Pola in Croatia on 30 December.

Her third sortie was relatively uneventful, starting and finishing in Pola between 2 February and 6 March 1942.

4th patrol and internment
On 29 April 1942, U-573 was attacked with depth charges by Lockheed Hudsons of No. 233 Squadron RAF, northwest of Algiers. Seriously damaged, she limped north to Spain, arriving in Cartagena on 2 May. International agreements allowed ships in neutral ports 24 hours to make emergency repairs before they were to be interned. The Spanish authorities granted U-573 a three-month period for repairs, which prompted several strong protests from the British Embassy in Madrid. On 19 May Heinsohn flew from Madrid to Stuttgart, then travelled on to Berlin, in order to discuss the situation with the Kriegsmarine. He returned by train via Hendaye (in southwest France) on 28 May. Realizing that even three months would not be enough to repair the boat, the Kriegsmarine sold the vessel to Spain for 1.5 million Reichsmarks. On 2 August 1942, at 10 am, (one day before the three-month period was due to expire), the Spanish navy commissioned the boat as the G-7.

U-573's crew suffered no casualties during her career in the Kriegsmarine. The men had been interned in Cartagena and were gradually released in groups of two or three. The last five members of the crew left with Kptlt. Heinsohn on 13 February 1943. He returned to the Kriegsmarinearsenal in Gdynia, then German-annexed Poland, In March he was ordered to Brest, then in German-occupied France to take command of U-438, and died with all his crew two months later.

G-7's repairs were completed in 1947. In 1958 Arca-Filmproduktion GmbH rented G-7 to take part in the semi-fictitious movie U 47 – Kapitänleutnant Prien, partially based on his patrol to Scapa Flow, where he sank HMS Royal Oak.

G-7 was renamed S-01 in 1961; she served in the Spanish Navy until 1970.

One other U-boat was interned in Spain during World War II: U-760.