What was the status of Soviet submarine development around 1989-1990? How great or small was their technological inferiority? Did Soviet submarines ever outperform U.S. submarines in any way?
Overall, no, although some subs did have features that were more advance/capable than USN subs. For example the Alfa class sub had a titanium hull, was wicked fast (40+ kts) and could dive much deeper than US subs (2200+ ft). But it was loud and thus easy to track. The reactors were usually the Achilles heel of Soviet subs - advanced in design and on paper but lacking in build quality and safety.
I took a tour of the Big Sur Naval Facility a few years back and the docent/guide was a former nuclear sub commander. According to him the Russian subs were no match for the Americans in those days.
I hear they had this super silent magnetohydrodynamic caterpillar drive.
(Apologies, I know it’s not a very creative reference, but somebody is bound to make it, so I figured it might as well be me.)
This is a great point. When I was in grad school, I wrote a lot about what was happening to the Soviet sub fleet after the collapse of the USSR. They always struggled with the maintenance of advanced components like reactors. Partly due to supply chain issues, but also because a lot of their supply and maintenance personnel were drawn from their worst recruits. They never seemed to understand how important supply and maintenance was to a modern military.
Which sounds like whales humping.
Modern Russian SSBNs have pump-jets, but I do not think that (in real life) magnetohydrodynamic ones have anywhere near the required performance.
Let me preface this by saying I’m not sure a factual answer can be given because any answer is necessarily subjective. Background: At the end of the Cold War (1986-1992) I was a submarine deployed Russian linguist. There are some things I still can’t talk about. Having said that…
The Soviet submarine fleet had one big weakness - upkeep and maintenance. Even the Deltas, Akulas and Alfas were relatively easy to detect because of their shitty condition. Soviet crews were also largely made up of conscripted sailors. Ironically, the workhorse of the Soviet fleet, the diesel electric Kilo, became a very formidable weapon after the collapse of the USSR. They even had at least one with a pump-jet drive.
AIUI, the Russian/Soviet philosophy has always been one of quantity over quality. Having the best submarine (or airplane, or tank, or warship) on a 1-to-1 comparison basis was never their intention. So, quality-wise, a Soviet sub would never be the equal of an American sub, since the Soviets were planning to win by numbers anyway.
That philosophy didn’t really extend to their subs. They could never make a lot of them, Titanium hulls and liquid metal nuclear reactors are insanely expensive. Poor QA/operational standards/maintenance is really the only thing that held them down. If they built/maintained their subs to Western quality standards (or at least to ROSCOSMOS standards), IMO they would have been on par with ours.
And they were intended to be rugged in a particular sort of way - specifically rugged for “long enough” under battlefield conditions with indifferent maintenance by conscripts. The thinking being that the war will be over or the device destroyed before maintainability becomes an issue. They weren’t used much in peacetime so as not to wear them out prematurely.
Makes sense for tanks, and rifles, and even aircraft to a certain extent, but subs never worked like that.
Meanwhile Western forces built their stuff with the intent of using it a lot in peacetime and as a result with a serious eye toward maintainability.
In practice the Soviets suffered from poor manufacturing and quality control coupled with designs that didn’t lend themselves to heavy use and maintenance.
Something to bear in mind is the differences in what the US/NATO and the Soviet Union designed and built submarines for. Traditionally submarines had been weapons of commerce warfare and coastal defense. While some NATO nations built submarines for coastal defense, the US had no need for coastal defense of itself. Commerce raiding was also pointless for the US in a NATO/Warsaw Pact conflict. The primary purpose of US submarines during the Cold War was to be hunter/killers of other submarines. The US/NATO needed to control the Atlantic. The USSR/Warsaw Pact didn’t need to control it; they just needed to deny its use by NATO. Which submarines are the perfect weapon for.
The standard size for heavyweight torpedoes has long been 21 inches/533mm. In 1973 Soviet submarines started appearing with 26 inch/650mm tubes in addition to 21inch/533mm ones. The reason was to allow them to use the Type 65 wake-homing torpedo which had the extraordinary range of 54 nautical miles/100km. It can be (relatively) blind fired into the where the probable wake of a surface ship is and then follow the wake to the surface ship that left it behind. This was extremely valuable for the Soviet Union and including 2 or 4 650mm tubes became the standard on all new Soviet nuclear submarines. For the US/NATO there was no need for such a weapon, so they stayed with 21 inch/533mm tubes and torpedoes, with the exception of the 3 US Seawolf-class submarines authorized/built and the very end of the Cold War which used 26.5in tubes, but for an entirely different purpose. The overlarge tubes on the Seawolf were designed to allow 21-inch torpedoes to “swim out” reducing the sound signature of them being launched. Presumably it wasn’t a very successful experiment, as the following Virginia-class submarines have returned to 21inch/533mm tubes.