Oberons have creep motors as well, and they certainly were detectable even whilst stationary. It simply is a matter from combat to combat as to how detectable your sub is, and no sub, however good it is technologically waas ever completely undetectable in all situation. For that matter no ship, of any description or nationality was ever unsinkable.
The earlier WWII sonars (eg type 144) are essentially as discriminating as those of the later Type 164s and 170s introduced 1950 and 1955, but simply with less power. What makes the problem difficult is the speed. Asdic wont work at speed, which means you need more escorts to track travelling at low speed, others positioning themselves to continue the tracking ahead of the sub, and others being directed onto the target to deliver the attacks. if the effective range of the Asdic is limited to 2500 yards as was the case with a type 144, you need more "stationary" trackers in your hunting group to maintain your search pattern. It doesnt mean the sub is undetectable. It means its more difficult to track and combat, and you need thickened up defences to beat it.
There is no such thing as an undetecbale target...at least no such thing that can have a blanket statement applied to it. There will be occasions when a sub is undetectable....thats what they rely on to deliver their attacks. Conversely ASW forces rely on detection to sink those subs. There is no such thing as a fullproof defence either, though that does not seem to be in contention here, since the germans were not manning the ASW forces.... They (the ASW forces) dont rely on detection to supress the target. If a sub is forced to submerge, it has a much harder task achieving a good firing solution. A submerged WWII sub, even a Type XXI is a relatively immobile target. Get him to submerge and you have the opportunity to re-route your convoy away from him. The problem with the Type XXI attack is that they could sustain high speed submerged for a relatively long time, but not indefinately, and not much greater than the speed of the a typical convoy. Suppressing a type XXI (ie forcing it to submerge and turn away) isnt as effective as it was against a type VII, but it was still effective, as it is against any conventional diesel electric boat. Only SSNs, with their relatively limiltless suibmerged speeds and power, can sustain a continual underwater attack .
The prize against conventional subs is of course to force the target to submerge in the first instance (thereby greatly increasing the survivability of your shipping because the sub loses its range and mobility advantages. In the second instance, the golden prize is to detect that submerged sub, achieve a firing solution and sink him. No submarine, at any time in history has ever been able to achieve that outcome every time. A type XXI as a piece of high tech kit was more likley than a Type VII, but not immune to detection and the density of the defences in 1945 would have meant its losses would still have been heavy.
To deliver an effective attack, a Type XXI equipped with unguided weaponary has to close to about 1000 yards to be effective. With a heavy amount of aircover, and the density of defences available to the allies in 1945, that a very tall ask. The germans hoped to counter that problem by attacking submerged using massed broadsides of Gnats. i have serious doubts that those tactics would have been all that effective. gnat was a weapon system more or less easily countered using towed arrays
I don't agree with your comparison between old and new relative capability. The newer systems had much better software search programmes and much better air component. I think helicopter dipping sonars revolutionized ASW missions.
You are making the same error again. What about the enhanced techs acquired by the submarine arm in that time. Sub detection and tracking systems exploded exponentially in the post war period, they also acquired weapons 10, 20 or 50 times as accuarate, and/or with greatly increased ranges. they acquired the ability to fired sub-launched SLAMs.
Whiskey was not comparable to the XXI, it was originally designed to counter the Type VII and was modified when Type XXI were captured . It could only manage 13 knots underwater .
I agree, but basing ideaas of overall capability on the basis of submerged speed alone is a poor way of determining the types overall capability. Speed is just one capability. The Ws could dive deeper, stay submerged longer and later had better weapons and electronics and detection gear fitted
The Type XXI was designed to have a design depth of 135 meters, which gives a crush depth of 340 meters and a maximum safe depth of 225 meters. However, when the finished product was tested, there was a minor problem in the design which reduced the design depth to 120 meters, so we get a crush depth of 300 meters and a maximum safe depth of 200 meters, rather similar to the VIIC. The deepest test dive was to 220 meters.
A W class had a design depth of over 200 meters, giving it a max design depth of about 350m. I do not know its maximum crush depth.
"During the five years following the end of World War II, Soviet exploitation of the Type XXI lagged significantly behind American fears. US intelligence initially foresaw in 1946 a force of 300 Soviet Type XXI equivalents by 1950. But it was not until 1949 that the first postwar Soviet submarine designs -- the Whiskey and the Zulu -- put to sea. While the Zulu was a true Type XXI, the Whiskey was a smaller, less capable, shorter range boat, designed more with an eye toward coastal defense and European littoral operations. It was not until the mid-1950s that Whiskeys were even given snorkels.
Early post-war construction focused on small submarines, the vast majority of which were Whiskey-class boats. Between 1949 and 1958 a total of 236 Whiskeys were commissioned. A shore targeting station would direct these vessels in their defense of the sea approaches to the Soviet Union. The larger Zulu-class and smaller Quebec-class submarines augmented the Whiskey-class. The thirty-two Zulu-class submarines operated further out at sea and coordinated with shore-based aircraft to provide targeting information to the shore centers. The approximately thirty Quebec-class submarines operated in the coastal waters.
During the 1950s there were efforts to convert Whiskeys into cruise missile submarines (SSGs). As the Soviet navy's mission expanded to combating the US Navy on the open ocean. The Echo I and Whiskey Long Bin class submarines deployed with anti-ship cruise missiles to fulfill this role."
They could dive