U.S. subs vs German

U.S. subs had air conditioning I have read, & German did not. German boats had a straight shot from conning tower to control room which made for faster dive. U.S. boats had a more indirect route. This data is from a US sailor who was on board a German captured boat that was brought to US after war.

U.S. subs could make 21 knots on surface compared to 16 knots for German boats. Both had forward & aft torpedo tubes.

Which could dive deeper? which had more range? Ones of similiar size that is.

 

The main issue to compare both would be a crucial one: Both submarine forces had the same strategic goal: isolate and 'starve' your insular enemy.

The German U-boats miserably failed in doing this whilst the American succeeded.

 

The German ones could generally dive to 350 to 400 feet safely and were occasionally pushed deeper. The US boats generally were designed to dive to 250 to 300 feet and could go a bit deeper too.
A big US advantage was far superior radar and ECM equipment. These both made evading aircraft attack and finding enemy units more likely. Both were items sorely needed by the Germans that never really were achieved in service.
The US boats also are much larger and have much greater range (as do most of the Japanese boats too).

 

I have read that compared to German U-boats the US submarines were slower to dive, a major disadvantage when faced with effective anti-submarine defences.

 

Wow! Define "miserably"!

 

Dive times are not as important as detection ability. For example, late war US subs in the Pacific generally had SJ and SS radar sets installed. These were sufficently accurate and long ranged that the boat could detect aircraft at distances that allowed plenty of time to dive to evade them. More importantly, they also provided an accurate enough picture of the aircraft's movement to allow the boat's commander to determine if the aircraft had indeed even spotted the boat or was heading for it. In cases where the aircraft wasn't headed for the boat it could continue to be observed while the sub stayed surfaced. Not having to crash dive everytime an air contact was made is a big advantage in both crew and boat effeciency. Radar and ESM also allowed US boats to more easily detect and track their potential targets. Both would have helped the Germans immensely.
However, the Germans adopted a "stealth" approach to electronics thinking that radiating continiously was more dangerous than beneficial. Thus, their use of primarily ESM devices like Naxos. It was a policy that greatly limited their offensive efficency and ultimately proved one of the major causes of their failure.

 

Am reading, Take her Deep. Which is about US sub Halibut. Here is a blip about depth;

Page 173. There is no doubt that we are still going down, deeper than we've ever been. Finally, at 405 feet the downward motion stops. Halibut is 35 percent deeper than her "test" depth!

Regarding radar, Halibuts skipper had this to say; Though our submarine weapons made only slight advances during the war, the improvements in electronics were remarkable. They gave us a decisive advantage over our foe. The most telling being the great impronement in radar performance.On march 21 1944, we put behind us the failures & frustrations of our last patrol & sailed once more, with hopes and morale high.

US subs were good boats, but torpedo problems made their performance in 42-43,( sinkings), not too spectacular.

Battleship Yamato was almost sunk by 3 US subs in an ambush, but she picked up the radar beams & turned 180 % & escaped.

Again US boats were very good, but effective use of US subs did not take off til late 43-44. The Captain of the Halibut mentioned German Wolf pack tactics were much superior & US did not really catch on. They did try small 3 boat wolf pack tactics & these had some sucess. Also US was slow to catch on to nightime surace attacking techniques.

So again sticking to boat quality US boats were very good, but effective employment of them took awhile. Spring 44 roughly speaking.

 

More US sub bits.

Halibuts skipper said ;After returning from a 43 patrol,Of the 23 fish fired, only one hit for a normal explosion, and 3 others hit as duds.Four torpedoes were positively tracked to enemy ships and went under them, while two others probably ran deep as well. Of the remaining thirteen torpedoes fired, the tracks were not observed because of visibility conditions. Some of them, too could have run deep or been duds.

Oct 43 these torpedo probs were largely fixed.

Another interesting comment was; As the war progressed, most submarine skippers preferred to keep radar silence in the vicinity of enemy aircraft, relying instead on the alertness and skill of their lookouts, and on constant readiness to dive before the plane could reach attack position. We had almost disdain for the threat which aircraft posed for submarines. This was more a mark of Japan's inferiority in ASW, or of her poor airborne electronics in particular, than a tribute to our boldness or the effeincy of our lookouts.

Very different ball of wax for zee U-boaters in atlantic.

I still am more interested in a nuts & bolts thread on US & German boats. One of the main British submarines had only torpedo firing capacity from one end, So really, the best boats were US & German. Japans boats were not as good, her torpedoes however were exellent. With 900 lbs of explosive compared to 500 to 690 in US torpedoes.

On the torpedo topic, I once read that a U-boat got a shot at the Rodney in 39 in south atlantic. Two hits, two duds. "That" would make your hair turn white. Rodney was one the ships that did most damage to Bismarck.

This could almost be a new thread, the big "almosts" of the war. The Yamato & Rodney almost sunk stories would certainly qualify. It would not have to be limited to navy oriented stories neccessarily.

 

Chrome have you been studying the late war German Walther boots by chance ?

this maybe a job for our esteemed forum member : Herr Kaleun

Erich ~

 

Not enough. The type xx boats were indeed yrs ahead of rest of world, as well as the gnat torpedo, schnorkel etc. The schnorkel was more than just a copy of the dutch design. I'll find the article on that. My interest is more regards 43 vintage boats, which US boats were very competitive with rest of world. When the U-505 was towed to US, it has been reported that US navy personnel were not overly impressed. & I once read a US claim that US subs were best, So this is what got me interested. I once read a book written by Britains top Sub captain. He said the German type V11 was the best. So, I'm compiling data to compare US & German mid war vintage boats.

 

More interesting comments from Halibuts Skipper;At this stage of the war Japanese shipping was becoming scarce.By the end of 43 Japan had lost 675 merchant ships totalling almost 3 million tons.

So despite torpedo problems, US subs did perform well. the larger percentage of Japanese merchant shipping was sunk by US subs.

Next quote; The heavy Japanese losses of aircraft and pilots and the great shortage of fuel due to tanker sinkings reduced the effiency of the Japanese ait effort. Taking all into account, when close to enemy air bases, I preferred not to use our omnidirectional air search,(SD),radar. Its unreliability was amply proven, and it could be a homing beacon for enemy planes.

This last comment is really interesting as it points out a similiar problem U-boats had with the biscay cross in giving ones position away by emitting signals. Which did happen with Yamato.

 

Schnorkel comment;We heard much of the snorkel used bt Germanys U-boats, but our navy did not adopt it. I had seen my 1st snorkel in 1938 in pearl harbor when a Dutch submarine of their O class passed through en route to the Netherlands East Indies. They used it chiefly to draw fresh air into the boat when submerged. Taking the idea, the Germans inproved on it. An enlarged intake pipe and an appropriate underwater exhaust allowed them to run their diesels while submerged.

So, it was a copied - improved idea.

Back to air conditioning. I read about a U-boat sunk off Florida coast. it had to surface as its crew were passing out from heat exaustion. It was sunk by a B-25 with air radar. If it had been air conditioned, perhaps it could have stayed submerged. So this was a neat advantage US subs had.

 

chrome,

I would strongly suggest getting Eberhard Rössler's The U-boat: The Evolution and Technical History of German Submarines and Norman Friedman's U.S. Submarines Through 1945. I believe that you will find both invaluable to your research on comparison.

German Type VII was designed specifically for convoy battles in the North Atlantic and the US Gato-class was designed as a fleet submarine (essentially a throwback to the old 'battleship theory' days where the sub would scout ahead of a battlegroup to locate the enemy.) This ends up being comparing 'apples and oranges' situation. But it is interesting nonetheless.

 

Will do. Britains top sub captain also said the type V11 was good for mediteranean operations as its maneuverability was very good. Could get in & out in shallow water without much difficulty.