Pr 613 'Nato Codename Whiskey' Class

Design History

Project 613 emerged from a WW2 program to build a successor to the prewar S and Shch class medium submarines. This was formalized in a 1943 TTZ for Project 608, essentially a modified version of the S class submarines incorporating war experience. This called for a 640 ton submarine, capable of 18 kts surfaced and 10 kts submerged. Armament was set at six 53 cm torpedo tubes (four bow, two stern), a 76 mm and a 25 mm gun. Project 608 was to be equipped with sonars derived from those supplied by the British under Lend-Lease.

However, in 1944, the Soviet Navy raised a German Type VIIC submarine, the U-250, that had been mined in the Gulf of Finland. Inspection of the wreck showed that Soviet submarine technology had fallen far behind that of Germany and other countries; in order to maintain the viability of the Soviet submarine fleet, a radical rethink was necessary. Postwar acquisitions included examples of the German Type XXI design, some features of which (principally increased underwater speed) were incorporated in the new specifications. The final TTZ for Project 613 was issued in 1948 and featured a much larger boat that the S-class based Project 608. There was also a subtle difference that was to become very significant; not being based on pre-war Soviet design art, Project 613 was not affected by the emergency diving depth restriction that hit Project 611 and all prewar Soviet designs.

The submarine was of double hull construction, the pressure hull being externally framed. It was divided into seven compartments: (a) forward torpedo room, (b) living quarters and batteries, © control room, living quarters and galley, (d) diesels, (e) electric motors and batteries and (f) aft torpedo room and living quarters. The machinery layout was twin-shaft with each shaft having a single 2,000 shp 37-D diesel engine to give a total of 4,000 shp. Each shaft also had a pair of electric motors, a normal sized motor for cruising and a smaller one for creep drive. For the first time in a Soviet submarine, the machinery was shock-mounted.

By the late 1950s, the design of Project 613 was becoming dated. A modernization program, designated Project 613U saw a drastic series of changes to the boats. The gun armament was removed, the superstructure streamlined and a snort installed in the rear of the sail. The sonars were upgraded, a new fire control system installed and additional fuel tankage provided. Preliminary work on a snort for Project 613 was undertaken in 1954 but the design used had a serious design defect that meant that diesel exhaust was sucked back into the living quarters of the boat. On initial trials, the crew suffered serious carbon monoxide poisoning and brought their boat back with grave difficulties. Recent accounts of the incidents speak of crewmembers with their limbs swollen to twice the normal size. A total of 22 units were brought up to Project 613U standard.

A less drastic series of modernizations, that deleted the guns, streamlined the sail and installed a snort but did not include providing new electronics or additional fuel became Project 613M. A total of 38 units had been brought up to Project 613M standard when additional modernizations were canceled. It is notable that most of the upgraded boats were the earliest in the class, suggesting that rebuilds and modernizations were to have been more widespread than was the case. By 1982, only the 60 Project 613U and Project 613M class boats remained in Soviet service. By 1992, only 18 Project 613U class boats were left, all in operational reserve. These were all scrapped the following year.

Final disposition

Unmodernized boats in this class not transferred abroad were scrapped in the 1970s. The Project 613M class followed in the 1980s and the last survivors of the Project 613U class went to the breakers in the early 1990s. None now survive in Russian service.

Time Line