Soviet Navy Project 748 submarine landing ship

In August 1965 TsKB-16, later Rubin, was directed to respond to the Tactical-Technical Elements (TTE) requirement for a large diesel-electric submarine LST designated Project 748. The design bureau, realizing the limitations of conventional propulsion for this submarine's missions, additionally initiated nuclear-propelled variants.

Six variants of Project 748 were developed with surface displacements from 8,000 to 11,000 tons. Most variants had three separate, cylindrical pressure hulls side-by-side, encased in a single outer hull. The first variant met the basic TTE; the second variant carried a larger number of PT-76 amphibious tanks; the third variant had VAU-6 auxiliary nuclear power plants; the fourth variant had two OK-300 reactor plants generating 30,000 horsepower; the fifth variant had the VAU-6 system with a single pressure hull; and in the sixth variant the OK-300 plant was replaced by four VAU-6 units.

This large submarine could carry up to 20 amphibious tanks and BTR-60P armored personnel carriers, and up to 470 troops. In addition to a torpedo armament of four bow 21-inch torpedo tubes with 18 to 20 torpedoes, the submarine was to be fitted with anti-aircraft guns and surface-to-air missiles. And, of course, the submarine could serve as a minelayer.

TsKB-16 recommended proceeding with the fourth (nuclear-propelled) variant. Still, construction was not initiated because the Navy, Ministry of Shipbuilding Industry, and General Staff of the Armed Forces ordered a review of the features of Projects 632, 648, 664, and 748 in an effort to develop a "ubiquitous" or all-capable nuclear submarine. TsKB-16 (now named Volna) was directed to develop a preliminary design for the submarine designated Project 717.

Sources:

"The First Soviet Giants" by Norman Polmar published in Undersea Warfare magazine:
http://www.navy.mil/navydata/cno/n87/usw/issue_13/soviets_giants.html

Cold War Submarines: The Design and Construction of U.S. and Soviet Submarines by Norman Polmar and Kenneth J Moore, Brassy's, Inc., 2004

Here are some drawings of Project 717, 748 and 612. I guess 612 is the oldest one. It was started in 1948.
Athpilot

Great post, thanks a lot.

Is that a hanger for re-con planes attached to the sail?

Yildirim said:

Is that a hanger for re-con planes attached to the sail?

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1940s prop fighters.

Per Norman's article in the original post, they were La-5 fighters.


I assume they were there to protect the beachhead. There doesn't seem to have been any provision for recovering the aircraft, so they probably would only fly one sortie and hope to find a field flat enough to land in.

Are there any dimensions for these monsters?

GTX said:

Are there any dimensions for these monsters?

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Dimensions are in Norman Polmar's book "Cold War Submarines". The Project 621 submarine LST of 1948 was 'only' 5,950 tons on the surface. And it was designed to carry a full battalion. The later Project 748 was 9,800 tons and 159m long with diesel power, more for the nuclear versions.

A few more images, however they say this is Project 717 !??

From the link: http://dsjunshi.net/forum.php?mod=viewthread&tid=819567&extra=page%3D1

毛子黑计划，717项目运兵核潜艇。1967年提出概念，1971年完成详细设计，潜艇长190米，排水量18000吨，最大潜深300米，最大水下速度18节。潜艇采用独特的三壳体结构，中央艇身容纳6枚533mm鱼雷、两座30mm机炮、兵员和两座反应堆，两侧艇身可容纳20辆两栖坦克或装甲车。可惜1977年这个登陆战利器被终结。

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Russian black program, 717 nuclear submarine project personnel carriers. 1967 proposed concept, detailed design was completed in 1971, the submarine is 190 meters long, displacement of 18000 tonnes, maximum diving depth of 300 meters, maximum underwater speed of 18 knots. Submarine uses a unique three-shell structure, central hull to accommodate 6 533mm torpedo, two 30mm cannons, troops and two reactors, flanked by boats can accommodate up to 20 amphibious tanks or armoured vehicles. Unfortunately, in 1977 the landings weapon was the end.

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Nice pictures,thanks alot Deino.




best regards


Pedro

Via the Top War blog, the Project 632 underwater minelayer/transport submarine, which was a precursor to Project 648:

In the middle of the last century, naval sailors of the Soviet Union ordered a special ship - an underwater minelayer mine support. The project was commissioned to work at TsKB-18, and in 1956, work began on the design of an underwater mine layer.

Due to the heavy load of TsKB-18 on the design of missile submarines, the design of the submarine ship, readiness of about 40 percent, is transferred to the team of TsKB-16.
Based on the requirements of the project, the submarine had to have a diesel engine and accommodate special weapons of the 90 order "PLT-6", specially designed for submarines, also had to be able to quickly convert the minelayer to a transport submarine for transporting people and transporting oil and fuel and water. Storage of special weapons was carried out on a revolutionary technology, the location of mines between compartments.
By the end of 1958, the project of the submarine “632” was adopted by the State Commission, but the project did not enter the seven-year shipbuilding plan, which began in December of 1958, but the submarine of the “648” project was included. All work after the approval of the seven-year plan for the mine layer project was stopped, and eventually stopped. Of the main reasons for not implementing the project, the high cost of batteries and the fact that the submarine of the project "648" could perform all the tasks solved by the project "632" and in addition could also perform other tasks of underwater transportation.

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I'm no navy expert. However, it seems they have a rather substantial draft. It woul seem the sub itself would be beached getting close enough to get the vehicles to wading depth. Then what? I've hung up boats a time or two on sandbars, and you just don't throw it in reverse and back off.

royabulgaf said:

Then what

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Flood the rear ballast tanks to raise the bow & put engines in reverse. Its a submarine: it have much more tilt control than surface ship.

How does this compare to the USN version ?? Sorry, can't remember if it was a 'real' project, or one of those 'napkinwaffe' 'Modern Mechanix' whatsits...

Via WarshipPorn, a bigger version of one of the photos that Deino found back in 2015:

From the YT-channel "found and explaine". Well worth seein! From the video description:
"In this video, we dive into the fascinating world of amphibious assault submarines. While the concept of these submarines, which are the theoretical equivalent of amphibious assault ships, has been explored by both the United States and the Soviet Union, none have ever been built. However, converted or standard submarines have often been used to transport small groups of soldiers or supplies.
In the Soviet Union, submarines played a crucial role during World War II, shuttling weapons, supplies, and special forces into besieged areas or behind enemy lines, notably during the siege of Sevastopol. After the war, the Soviets proposed Project 621, a landing ship-transport submarine that would have been one of the largest submarines of its time. It was designed to carry a full infantry battalion, tanks, trucks, cannons, and even fighter aircraft. Unfortunately, Project 621 was never built.
Undeterred, the Soviets continued to explore larger and more ambitious designs, such as Project 664 and Project 748. These submarines were intended to have additional capabilities, including underway replenishment for other submarines and submarine rescue. However, the complexity of combining these various functions, along with the need for nuclear propulsion, proved challenging, and these projects were eventually abandoned.
Meanwhile, in the United States, preliminary designs for submarine transports were also explored. In the 1950s, a massive 10,000-ton submarine capable of carrying 2,240 Marines was proposed. However, the extent of the U.S. Navy's design efforts in this area never reached the scale of the Soviet projects. Instead, older submarines were often refitted for transport purposes, particularly for covert operations and special forces deployments.
Although the amphibious assault submarine remains a theoretical concept, the ideas and lessons learned from these projects have influenced subsequent developments in the field. Join us as we explore the history and potential future of these remarkable vessels and their impact on naval warfare."

<iframe width="560" height="315" src="View: https://www.youtube.com/embed/e711I4m-2bY?si=6gW9YZzTXCdd8dHq
" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>

A screenshot from the video of Found and Explained :