Russia's Alfa Class Sub Could Out Run & Out Dive Anything (But Had a Fatal Flaw)

[Onkel Neal]

http://nationalinterest.org/blog/the...anything-22121

early Soviet nuclear submarines struggled to compete with the West in stealth and reliability. After the first few designs came to fruition, the Soviets decided to undertake a combination of brute force and extremely risky high technology. The brute-force part meant building a submarine that could move faster and dive deeper than any Western counterpart; the high-tech part meant innovative hull design, reactor design and material manipulation. The result was the Type 705 Lyra (known as Alfa in NATO), a submarine that the West regarded as a profound, if short-lived, threat to its undersea dominance.

[speed150mph]

The alfa sure came as a shock to the NATO navies, who were used to being the kings of the sea, makes you wonder where Russian submarine tech would be if they didn't have the severe cutbacks they did after the fall of the USSR.

I have a couple questions for the subsim community about the Russian Titanium hulled boats.:

First off, I read an article once about how the CIA found out and were shocked that the Alfa hull was made of titanium. But K-222, the only papa class sub, had a titanium hull and was commissioned almost 4 years before the first alfa test bed. How long was it before NATO learned K-222 had a titanium hull?

Secondly, I've heard stories that some of the alfa hulls were suffering from metal fatigue after diving deep, and that this coupled with the maintenance issues with the reactor is what caused them to be decommissioned and scrapped. Can anybody confirm this?

Thirdly, if the above is true, what changes were made to the Sierra class that made them more durable? They have a deeper test depth then the Alfa, and they have already exceeded the life of the alfa with no indication of them being decommissioned soon. Heck, one was involved in a collision with a LA class sub that forced the 688's early decommissioning and the sierra got away with a 4 month dry dock visit and didn't look back.

[Mr Quatro]

Good questions speed150mph and as for the Alpha class even the Russians have to go by budgets and the cost was just too much for what they would get in the end. Look how long it took to finish what they started way back in 1993.

https://russianmilitaryanalysis.word...nhills/page/2/

After the collapse of the Soviet Union, submarine production slowed and then came to a halt. The first prototype Yasen-class SSGN—the Severodvinsk—was laid down in 1993 and the first Borey-class SSBN—the Yuri Dolgorukiy—in 1996, but construction on both ceased soon after. In the decade or more of that hiatus, both sub­marines were extensively redesigned, and when they belatedly went to sea they were very different from their original designs.

"Submariners are a special brotherhood, either all come to the surface or no one does” ~ Vice Admiral Rudolf Golosov of the Russian Navy

The future of undersea warfare is already available ... Like Sputnik the USA is far behind. We need to build submarine drone tenders and we need to build them soon in order to counter the Soviet threat of an Arctic fleet of Russian drones that could be controlled by satellites.

https://russianmilitaryanalysis.word...nhills/page/2/

Beyond combat submarines, there is another Russian submarine force that answers to its own command. The Navy’s General Directorate of Under­sea Research (GUGI) maintains several special-purpose undersea craft. Some are conversions of older submarines, such as the Delta “stretch” SSBN designs, while others are new construction units. These special-purpose submarines—nuclear and diesel-electric—are employed in several roles, including supporting submarine weapon and systems development; con­ducting deep-ocean antisubmarine proj­ects; and mapping and possibly interdict­ing seafloor fiber-optic cable networks. Some of GUGI’s submarines serve as mother ships for deep divers such as the “Losharik” special-purpose subma­rine. Others may deploy underwater drones with nuclear warheads such as the recently revealed “Status-6” weapon, which will be carried externally. Many press reports credit the Status-6 with incredibly high speed, long range, and a multi-megaton warhead—claims that likely are unrealistic. But even if those performance figures are off significantly, it still will be an innovative weapon and need to be countered

[jaop99]

Is a good article, in the end, the Lyra project was the development platform for the new Yasen class submarines, highly automated and with a small crew.

[Hinrich Schwab]

Originally Posted by speed150mph

Secondly, I've heard stories that some of the alfa hulls were suffering from metal fatigue after diving deep, and that this coupled with the maintenance issues with the reactor is what caused them to be decommissioned and scrapped. Can anybody confirm this?

This is true. Titanium while lighter and as strong as steel, lacks the flexibility many good steel alloys possess. While titanium can withstand pressures that would crush steel, titanium and its alloys are much more brittle and have fewer compression cycles before metal fatigue sets in. For all of the raw power Alfas possessed, because of the design choices made in their construction, they were doomed to have shorter life spans.

[speed150mph]

Hinrich, thanks for confirming that, but there was a second part to the question. If the hulls were cracking on the alfas from fatigue, then what changes were made to the design for the Sierra class subs that afforded them a deeper test depth, and have extended their life to the point where, aside from the one that collided with the Baton Rouge, none have required extensive hull repairs?

And obviously they believed they solved the issue with the mike class sub, since they upped the test depth to over 1000 meters and did not seem concerned to operate her at extreme depths.

[Kapitan]

Come on Neal we both know the picture is a project 971 Akula, and we both know the 705's we rapid noisy at high speed and had some issues being early boats with their reactors being lead bismuth instead of pressurised water.

National interest clearly cant tell the difference.