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Naval Warfare

S-99 (Project 617 / Whale-class)

Diesel-Electric Attack Submarine [ 1956 ]

S-99 was the only submarine completed by the Soviets to the Whale-class standard - it served as an experimental platform.

Authored By: Staff Writer | Last Edited: 12/23/2020 | Content ©www.MilitaryFactory.com | The following text is exclusive to this site.

Both the Soviets and Americans benefitted from captured German submarine technology in the period following the end of World War 2 (1939-1945) with both respective navies taking different paths to achieve the powerful nuclear-propelled versions seen today. During this time, the diesel-electric attack submarine still maintained its value around the globe and German engineers developed their more impressive designs towards the end of the conflict - namely the unfinished wartime Type XXVI.

The Type XXVI U-boat was intended as a long-range, deep water solution utilizing the Walter "Air-Independent Propulsion" (AIP) system as part of its propulsion scheme. While build contracts were handed out to ship-builder Blohm und Voss before the end, only sections of the boats were completed when Germany capitulated in May of 1945. it was this framework that made up the Project 617 boat of Soviet origin - known to NATO as the "Whale-class" - and only a single experimental type was completed for the Soviet Navy. The earlier Project 616 work benefitted the subsequent Project 617 (Whale-class), being able to reach underwater speeds of some 19 knots. Project 617 was started in 1949.

The boat's profile was traditional for the time, the sail/fin being set at midships. The bow was well-rounded though still boat-like as seen in World War 2 types. The aft section included the rudder controls set aft of the spinning propeller shaft. The submarine was armed through six torpedo launch tubes all fitted as bow-facing mountings with twelve reloads carried. The torpedo room too its usual place at the bow of the submarine and other sections included crew living quarters, battery room, diesel and electric engine rooms, a sealed turbine room, and the command room. The typical crew complement reached 54 personnel.

Propulsion was through a diesel-electric arrangement including an AIP Walter turbine system giving the boat good power. This allowed the design to maintain a surfaced cruising speed close to 11 knots but, more importantly, reach beyond 20 knots when submerged. Endurance was up to 45 days and the hull could sustain the boat to depths of over 550 feet.

The single submarine example began construction on February 5th, 1951 and was launched in an incomplete state exactly a year later to undergo its requisite sea trials. During this period, the boat achieved speeds of up to 22 knots while submerged, making it the fastest undersea boat in Soviet Navy history and propelling the service towards the future. She was completed on March 20th, 1956 and undertook additional trials into the latter part of the decade. When tested near a depth of 260 feet during a 1959 trial, an explosion forced her to surface and return home under the power of her batteries. This marked the end of the project and the boat was decommissioned and ultimately scrapped after 1959.©MilitaryFactory.com
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Service Year

Soviet Union national flag graphic
Soviet Union

Destroyed, Scrapped.



National flag of the Soviet Union Soviet Union (retired)
(OPERATORS list includes past, present, and future operators when applicable)
Submerged Attack
Traveling under the surface to search, track, and / or engage or reconnoiter areas.
Maritime Patrol
Active patroling of vital waterways and maritime areas; can also serve as local deterrence against airborne and seaborne threats.
Fleet Support
Serving in support (either firepower or material) of the main surface fleet in Blue Water environments.

204.0 ft
62.18 m
20.0 ft
6.10 m
16.8 ft
5.12 m

Installed Power: Diesel-electric propulsion scheme with AIP Walter turbine unit driving shaft arrangement at the astern.
Surface Speed
11.0 kts
(12.7 mph)
Submerged Speed
20.0 kts
(23.0 mph)
261 nm
(300 mi | 483 km)

kts = knots | mph = miles-per-hour | nm = nautical miles | mi = miles | km = kilometers

1 kts = 1.15 mph | 1 nm = 1.15 mi | 1 nm = 1.85 km
6 x 533mm torpedo tubes (all bow-facing) with 12 x Torpedo reloads.

Supported Types

Graphical image of an aircraft aerial torpedo

(Not all weapon types may be represented in the showcase above)

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