US vs. German subs - which was better?

[1480]

You could compare the submarines, but not in a head to head competition. You have to come up with subjective categories and evaluate them in each. Not dive times and crush depth but more along the lines of actual patrol time , percentage of machinery malfunctions, down time on refit, sinkings during a patrol etc. to come up with a level field of play. I found it interesting that military channel had their top ten submarine episode, the Gato/Balao came in 3rd and the Type VII came in 1st.

[Dowly]

Originally Posted by Phaedrus

Its a little like asking:

What was better?

A Spitfire or a B-17?



Two different designs, for two very different theatres, and two different missions.

Messerschmitt 109 :rotfl:

[Sailor Steve]

Just what I was going to say, Dowly. And as in the case of the submarines, the only possible real answer is: yes.

[Schöneboom]

Another way of framing the question: If you were being hunted down by Allied ASW units of 1943-44 vintage, which sub would you rather bet your life on? Perhaps the right answer in this case is, "None of the above"!

[Hitman]

Another way of framing the question: If you were being hunted down by Allied ASW units of 1943-44 vintage, which sub would you rather bet your life on?

A russian Kilo class

No WW2 was suited to survive against the highly effective ASW methods developed by 1944 except the Type XXI and XXIII, but those came too late :hmm:

Americans were of course lucky to have the IJN as opponent, but ultimately I insist that the comparison between a Type VII and a fleet boat is impossible. If you don't trust me, then take Pearl Harbor as starting base and go patrol the Japan coast in a Type VII. Sure, you might kill lots of merchants, but you will run out of torpedoes and fuel long before a fleet boat does. And if you want to carry enough torpedoes and fuel to the japanese coast, then you need something way bigger....like a fleet boat

Apples and onions!!

[predavolk]

The fleet boat is the better offensive weapon, but as has been pointed out, the odds of it surviving against determined ASW are worse. Active radar in particular would have been a dead giveaway. The Type XXI was, of course, the best sub of the war- by far. I'd take the evaluation of their enemies with a grain of salt- especially given how feared the U-Boat threat was. But I'd concede that by that time in the war, manufacturing was a crucial liability to the type.

[Catfish]

Hello,
while there seems to have been no detector for the radiance caused by radar-detecting equipment like the Metox or the later devices, there certainly was for active radar. Don't know why the japanese should not have had and used it against US submarines ?
Even if it was feared by german commanders that the unwanted radiance of radar detecting devices gave away their position i think there never really was any such device on the allied side that would have been able - or was there ? - anyone ?

Regarding "which boat was the best": apples and onions, yes. And the radar equipped fleet boat with the late electro-mechanical targeting computer was not present until the late war, as well as the IX DII or the XXI type with their food freezers and the automatical target computer using sonar for a firing solution, with which torpedoes could be fired at a depth of 50 meters.

As it was said the manufacturing quality of the XXI type was bad, which is certainly true, but the computed theoretical crush depth was at 330 meters, or almost 1000 feet - operational depth was some 220 meters, or 660 feet, which was reached by all operational XXI types. Even some VIIC boats have reportedly dived to more than 300 meters as well, if not always intentional...
The real Walter boats with their hydrogen-superoxyde AIP propulsion also were very advanced, but not ripe for operational status, and there certainly were problems with the fuel needed for the turbines (difficult to produce and handle). One major advantage anyhow was the silence of the Walter boats, they would not be heard by hydrophones even at a speed of 15 knots submerged, top speed of the V80 (Versuch=trial) was a noisy 28+ knots submerged, as it was again tested after the war. Would this really be the "best boat" ?

Then the german doctrine of the U-boat war was a bit antiquated - the "new" type VII U-boats had basically the properties of the WW1 ones - diving max. depths as well as reliability were better, but speed surfaced and submerged was not. The type VII was intended to attack surfaced with the "Schnellboot-Taktik", or even stop and sink merchants with the deck gun following prize regulation, like in WW1. The total or unrestricted u-boat war was not so self-evident at the beginning of the hostilities.
At first this tactic worked out well, boats attacking surfaced at speeds of 18 knots could outrun early escorts, and merchants, and the praised hydrophones and ASDIC were useless against ships attacking surfaced. It was not before the boats were forced to dive, that ASW ships gained a real advantage.

Concerning equipment and "comfort" (lol) i would prefer a late Gato or Balao (if only because of the ice cream feature), but as soon as it gets to diving ... try to survive a british ASW group in a low-diving fleet boat with its max depth of 400 feet/130 meters in the Atlantic ocean ... I often wondered why US boats did have no greater diving depth ?

IMHO the scenario in which the boat is to be used, and at which time, would be the main argument - which has certainly be said before somewhere, and why i will stop here .

Greetings,
Catfish

[Puster Bill]

Originally Posted by Platapus

Back in March we had this discussion.

http://www.subsim.com/radioroom/showthread.php?t=133357

Read the sixth post in that thread for what Clay Blair wrote about the US evaluation of the Type XXI

Some of Blair's criticisms are, well, unfair.

Don't forget, while US and German subs were a product of their times, so was Clay Blair. One problem that I have with Volume II of "Hitler's U-Boat War" is that he denigrates the Type XXIII as being too small to accomplish anything. Yet in 1945, they had the best record of any u-boat class, sailing on 10 missions with 5 ships sunk to their credit and 0 operational losses.

Having read both volumes of "Hitler's U-Boat War" now several times, I get the impression that Blair was kind of biased towards big fleet-type boats like the ones he served in during WWII, and that this bias creeps up from time to time.

Some of his criticisms:

Underpowered Diesel Engines

The new model, six-cylinder diesels were fitted with superchargers to generate the required horsepower. The system was so poorly designed and manufactured that the superchargers could not be used. This failure reduced the generated horsepower by almost half: From 2,000 to 1,200, leaving the Type XII ruinously underpowered. Consequently, the maximum surface speed was only 15.6 knots, less than any ocean going U-boat built during the war and slightly slower than the corvette convoy-escort vessel. The reduction in horsepower also substantially increased the time required to carry out a full battery charge.

This would be a major problem for a fleet-type boat, designed to spend most of it's time on the surface. The Type XXI was designed to basically spend *ALL* or most of it's time underwater, either on batteries or schnorkeling. While the battery recharge time is an issue, surfaced top speed really isn't. From a tactical standpoint, it doesn't matter that much.

Even the increased recharge time isn't a major issue, because while schnorkels and periscopes could be detected on the centimetric radar used late in WWII, it was at a much reduced range compared to a surfaced boat.

Imperfect and Hazardous Snorkel

Even in moderate seas, the mast dunked often, automatically closing the air intake and exhaust ports. Even so, salt water poured into the ship’s bilges and had to be discharged overboard continuously with noisy pumps. More over, during these shutdowns, the diesels dangerously sucked air from inside the boat and deadly exhaust gas backed up, causing not only headaches and eye discomfort, but also serious respiratory illnesses. Snorkeling in the Type XXI was therefore a nightmarish experience to be minimized to the greatest extent possible.

If you are using the schnorkel, that means you are running very noisy diesel engines, so running noisy pumps isn't really a problem. Schnorkels were problematic in the beginning, but that doesn't mean they weren't going to be used. In fact, in Blair's own work (last half of Volume II) you can see the difference in surviveability between boats with and without schnorkels. The boats with schnorkels, and that used them, had a much better chance of surviving. Fixing the issues with the schnorkels was an engineering issue, not a fundamental problem with schnorkels themselves. I'd point out that *ALL* submarines today, even the nuclear ones, have schnorkels.

Again, this shows that Blair is a product of his experiences (as are we all).

His points about the hydraulic system and hull integrity are well taken, however.

One other point I would like to make is that the US boats never had to face an opponent equal to that faced by Germans, especially late in the war. The reason that the US Navy could keep the same basic design throughout the war with the only real improvements being to the electronics and diving depth is because they didn't face the same ASW pressure that the Kriegsmarine faced.

Consider what the losses would have been like in the Pacific if the Japanese were able to:
1. Develop and field centimetric and millimetric airborne ASW radars.
2. Decode traffic between boats and their control back on shore.
3. Keep the naval resources to "hunt to exhaustion" a submarine contact.
4. Develop more advanced SONAR, and to deploy them in great numbers.
5. Develop an ASW homing torpedo like the Mark XXIV FIDO.
6. Develop ASW weapons like the Squid and Hedgehog.

Those are just some of the things I can think of off the top of my head that the Germans faced in the Atlantic, that weren't an issue for the US in the Pacific. One could argue that the real reason for US successes in the Pacific was more because Japanese ASW doctrine and technology was woefully neglected compared US/British practice than because the US subs so technologically superior.



By the way, my criticism of Blair shouldn't be read to invalidate the main thesis of his work. It stands as a monumental and never equalled summary of the U-boat campaign in WWII.

[onelifecrisis]

Originally Posted by Dowly

Messerschmitt 109 :rotfl:

Pfft.
How can you even put that Bf109 heap of junk in the same category as the Supermarine Spitfire!?
Yeah yeah, fuel injectors, negative-g's, highest kills of any aircraft, blah blah, boring...
What you really want is eight machineguns superglued to a Merlin.

[rifleman13]

Originally Posted by onelifecrisis

Pfft.
How can you even put that Bf109 heap of junk in the same category as the Supermarine Spitfire!?
Yeah yeah, fuel injectors, negative-g's, highest kills of any aircraft, blah blah, boring...
What you really want is eight machineguns superglued to a Merlin.

Like a P-51?:hmm:

[onelifecrisis]

Originally Posted by rifleman13

Like a P-51?:hmm:

2nd choice
Hey I just check wikipedia... it says 6 guns. :hmm:

[msalama]

Yer Biffers, Ponys and Spits... BAH!!! The sexiest prop fighter of all time is, of course, Yak-3.

Er, I'll get me coat then

[Puster Bill]

Originally Posted by msalama

Yer Biffers, Ponys and Spits... BAH!!! The sexiest prop fighter of all time is, of course, Yak-3.

Er, I'll get me coat then

False. Sexiest prop fighter of all time:



Albatros DVa

(This is the one at Old Rhinebeck Aerodrome)

[Dowly]

Originally Posted by onelifecrisis

Pfft.
How can you even put that Bf109 heap of junk in the same category as the Supermarine Spitfire!?
Yeah yeah, fuel injectors, negative-g's, highest kills of any aircraft, blah blah, boring...
What you really want is eight machineguns superglued to a Merlin.

Bah! Nonsense! I bet the Spits came true to their name, spitting fire as they were spiraling down towards the mother earth when someone like Hans-Joachim Marseille was peppering them with his 109.

[Sailor Steve]

Originally Posted by onelifecrisis

2nd choice
Hey I just check wikipedia... it says 6 guns. :hmm:

True, but the P-51 had six Browning .50s, as opposed to eight .303s.

So, who had the better trench-digging shovels?