US fleet boats - best frontline sub of ww2?

[Schroeder]

Originally Posted by Gino

This meant snorkels, all over welded hull, greater underwater speed, better silent running, faster torpedoloading (15-20 min for a "total refill", by the way, not 5), radar, anti-'anti-submarine' defense system and maybe some more.

Well, the guys who have the actual submarine there say that it can reload within 5 minutes (fünf Minuten). Is the info about the reloding time too from that book you mentioned?:hmm:

[Gino]

Originally Posted by Schroeder

Well, the guys who have the actual submarine there say that it can reload within 5 minutes (fünf Minuten). Is the info about the reloding time too from that book you mentioned?:hmm:

Nope, my info comes from: Eckard Wetzel: U2540 - Das U-boot beim Deutschen Schiffahrtsmuseum in Bremerhaven, page 35. "Da die alten Kampfboote sich oftmals um ihre Erfolgschancen brachten, weil sie ihre Torpedorohre nicht rechtzeitig nachladen konnten, erhielt der Typ XXI eine neuartige Torpedo-Schnellladevorrichtung, die es ihm ermöglichte, 18 Torpedos in schneller Folge abzuschiessen. Das nachladen der 2. Chargierung dauerte maximal 15 Min. für die 3. Chargierung (Torpedos aus der Reservelagerung) würde geschultes Personal knapp 20. Min. benötigen." You see, same boat, different book (published in 1996)

For those that cannot read German: Because the old boats could not load their torpedoes fast enough to get better results, the type XXI received a new torpedo loading device. This made it possible to load the second charge within maximum 15 minutes. The third charge could be loaded by a trained crew within 20 minutes.

I think that 5 minutes for 6 torpedoes, even with an automatic loader, with a trained crew is a little on the short side. Perhaps a very well trained crew in optimum circumstances could have pulled it off, but I stick to the less than 15 minutes.

groetjes,

[Captain Vlad]

Originally Posted by Rockin Robbins

When you think "dive bomber" you think Stuka.

Some of us think 'Dauntless'.

[Torplexed]

Originally Posted by Captain Vlad

Some of us think 'Dauntless'.

Yeah! :p

Actually when it comes to German tanks I've always thought the Panther a deadlier looking customer than the Tiger. Not as heavily armed but faster.

[tater]

Originally Posted by Captain Vlad

Some of us think 'Dauntless'.

Beat me to it.

[gimpy117]

Originally Posted by Gino

I guess I wasn't clear enough. I didn't mean to say that the Porpoise already had those features you mention. Of course not. What I meant to say is that the Fleetsubs that were Guppied (i.e. upgraded) after the war, came very close to, or were even better than the XXI. So, the fleetsubs 'only' had to go through an upgrade program to get the same speeds as the XXI, whereas the XXI was a newly designed boat.

Some facts (this time I made my walk to my library )
I give you the numbers for maximum surfaced speed, and maximum submerged speed:
XXI: 15.6 knots / 15 knots.
Guppy I: 17 - 18 kn./ 15 kn.
Guppy II: 17 - 18 kn. / 15 kn.
Guppy III: 17 kn / 14 kn.
Still, keep in mind that the Guppies were 'old' fllet boats that had 'some bodywork done'. (pimp my boat )

USS ALbacore, that was built as a new design in 1952-53 already did 20+ knots submerged. (surf. 25 kn). The Albacore was based on Guppy and XXI, so maybe that is a bit poluted data there.

As for the automatic torpedo loading feature the XXI had. Guess what? The Dutch submarines O-19 and O-20 (commissioned in 1938) already had a half automatic torpedo loading system. They also were the first submarines with a snorkel!
It could be that the germans used the plans of the new dutch submarines, some of them were captured in 1940, to design the XXI.

groetjes,

well, the XXI was deployed in low numbers if I'm not mistaken...

[Nephandus]

Now I must say that I find this discussion highly amusing...

In my opinion it is hardly feasible to compare German U-Boats and US Fleetboats as they were based on completely different design ideas and intended areas of operation.

German U-Boats were strictly planned for merchant warfare, Fleetboats were intended for support of taskforces (it's not their fault, the possible taskforces were bombed into nigh oblivion at the beginning of the war in the Pacific).

As for the technology.... U-Boats were generally smaller than Fleetboats. Even the Type IXD (which happens to be one of the largest operational U-Boats) was smaller than the Balao (also the Type XXI was smaller).

The advantages of the U-Boats over the Fleetboats were generally faster dive times and a deeper dive depths. Also the maneuverability of the U-Boats was greater than that of the US Fleetboats.

Regarding speed, usually the US boats were better because they were designed to keep up with a surface fleet. The U-Boats never had this design notion and being used against slower freighters, speed was less a factor than stealth. One thing has to be noted though.... the speed of the Fleetboats was usually app. 3-4 kn higher on the surface and about 1-2 knots submerged.

As for the range... well... since the Type VII was comparable in size to the S-Class it is hardly surprising that the maximum range was somewhat comparable.

The Type IXC, IXC/41 and IXD had actually a greater range than the Balao.

Regarding the armament... well... the fleetboats had more Torpedos tubes (Balao: 6/4 with 24 Torps in total compare to Type IXC: 4/2 with 22 in total) but then again they where by design thought to act against enemy warships.
One should factor in though that the German torpedos had two advantages.... they were more reliable and had a higher explosive yield than the US counterparts (also the G7e Torp had a way better performance than the Mark 18, which was a copy of the former).

The Type XXI is actually a completely different story not being a dive boat anymore. This thing was designed to completely stay underwater therefore sacrificing surface speed for underwater speed (which was more then 70% higher of that of the Balao). The hull had basic streamlining which no Fleetboat parttaking in operations had in WW2. Actually... fact is that most early post-war submarines of the US shared the hull design of the Type XXI (btw... of the Type XXI 118 were built.... but without bases in France it poses to be somewhat difficult to reach any convoy routes in the Atlantic... especially if the war is lost anyway).

Furthermore... not only the boats were radically different in design concepts... also the type of submarine warfare of both theatres were radically different. The US pitted its submarines against an opponent who had virtually no experience in submarine- and ASW-warfare. The Japanese sonar was not nearly as efficient as the British counterparts, there were virtually no efficient ASW doctrines in the IJN and escort duty was considered a disgrace. Convoys were not common practice and air-coverage was very limited due to the vastness of the area of operations.

Compared to that, the UK adopted the convoy system quite early having experience with that and knowing its efficiency from WW1. The ASW warfare was perfected during the course of the war, providing permanent aircoverage by landbased and escortcarrierbased aircraft, covering the submarine bases as well. Also perfecting detection gear (high frequency direction finder, ASDIC, Radar) and weapons (Hedgehogs) did provide a hard time for the U-Boats.

And finally, the goals of the respective sub-wars were different.... the Germans attempted to choke Great Britain to force peace by cutting supply to their Airforce and Army... the US attempted more to choke vital supplies for the Japanese Airforce and Navy.

[Torplexed]

Originally Posted by Nephandus

In my opinion it is hardly feasible to compare German U-Boats and US Fleetboats as they were based on completely different design ideas and intended areas of operation.

There were several instances in the thread where this was brought up. The apples and oranges argument doesn't seem to cut much ice anymore.

[tater]

Results matter. Not winning battles, but winning wars—or at least campaigns.

Fleet Type submarines wiped out the japanese merchant marine. Regardless of the initial design intention (the "fleet" bit), they turned out to be excellent commerce raiders (~90,000 tons per boat lost).

The KM boats were designed for commerce raiding, but for all the talk about superior depth, maneuverability, etc, they sank what, around 3 ships each before being themselves sunk (something like 11,00tons per lost boat)? Clearly they were neither deep-diving enough, nor maneuverable enough, which begs the question: were u-boats actually all that well suited to the Battle of the Atlantic?

If they evolved the superior form for their theater, they would not litter the bottom of the Atlantic.

[Freiwillige]

But Tater, Would the outcome be much differant if the Germans used Fleet boats? I am sure the Atlantic would still be full of dead submarines. Yes for the record I do beleive that the Fleet boat is the superior submarine to the U-boat. Well Pre- XXI that is.

And the point about the XXI that most people are missing that made it truly dangerous was not the fact that it could go fast underwater. It was the fact that it could go fast under water rather quietly and for a much longer time than any sub of its era. On all submarines batteries ran out rather quickly and escorts could just keep a sub down and wait and at worse the enemy could slip only so far at 2 knots before he had to come up again. XXI's could go much farther, faster and longer. Making it far more dangerous offensivly as well as defensively.

[tater]

I was confining my thoughts to subs that saw service. Only a few of the many built were even close to putting to sea, right?

XXI was an amazing boat, clearly.

As for the what-if, I have no idea, but you are probably right that fleet boats would do no better.

Fleet boats would have to do MUCH WORSE, however to lose this particular argument, IMO.

U-boats operating in place of USN subs would do poorly in the PTO, while Fleet Types would likely do no better.

Note that long range---and long submerged range---combined with surface speed does directly translate into survivability when ASW doctrine revolves around saturating a cirle which defines the max submerged endurance of the target. Watch that circle, and the target MUST surface in time. The bigger the circle, the more assets required to watch it.

[A Very Super Market]

Japanese ASW tactics were primitive and limited even during the late stages of the war. The Japanese merchant fleet operated in obvious routes, poorly escorted ones at that, which gave the fleetboats an innate advantage in ship sinkings. I find your argument that U-boots were poor commerce raiders to be unfair, the early war situation closer to what the Japanese scenario was like delivered similar results.

[Freiwillige]

How do Japanese subs compare to the U.S. fleetboats I whonder. I know little about them but I did read an article tonight in one of my old WWII magazines about I-17 shelling an oil refinery off the Santa Monica coast in feb. 1942. It has some small details about the I class Japanese subs. Seems fast enough, Has plenty of torpedo tubes and a friggen airplane hanger that can launch a biplane in 15 minutes!

[Nephandus]

Originally Posted by tater

Results matter. Not winning battles, but winning wars—or at least campaigns.

Fleet Type submarines wiped out the japanese merchant marine. Regardless of the initial design intention (the "fleet" bit), they turned out to be excellent commerce raiders (~90,000 tons per boat lost).

The KM boats were designed for commerce raiding, but for all the talk about superior depth, maneuverability, etc, they sank what, around 3 ships each before being themselves sunk (something like 11,00tons per lost boat)? Clearly they were neither deep-diving enough, nor maneuverable enough, which begs the question: were u-boats actually all that well suited to the Battle of the Atlantic?

If they evolved the superior form for their theater, they would not litter the bottom of the Atlantic.

I'm sorry to tell you, but you are missing some points from the equasion. You are giving credit for success only in the light of the boats itself.

Fact is: the Fleetboats sank app. 5.2 million tons of ships against an enemy totally oblivious of concerted ASW procedures and usually having merchants travel solo without any escort and aircover.

The U-Boats sank 14.3 million tons against an enemy deeming them as their principal enemy going lengths in measures to defeat them.

It is quite clear that the US submarine force had it a lot easier. Their boats weren't bombed while in port or just leaving port. They did not have to go up against strongly defended convoys having air cover. Neither did they have an enemy who could monitor their radio traffic due to the communications code being broken. They didn't even have their bases in areas that could be said to have hostile inhabitants.

I guess it is definitely a difference wether your enemy takes to you dead serious or to be a nuisance not to be really bothered with until it is too late.

[Nephandus]

Originally Posted by Freiwillige

How do Japanese subs compare to the U.S. fleetboats I whonder. I know little about them but I did read an article tonight in one of my old WWII magazines about I-17 shelling an oil refinery off the Santa Monica coast in feb. 1942. It has some small details about the I class Japanese subs. Seems fast enough, Has plenty of torpedo tubes and a friggen airplane hanger that can launch a biplane in 15 minutes!

Well.... the Japanese subs were technically some of the most advanced models being higher in range, able to submerge deeper and being more resilient. One type even had a submerged speed higher than the Type XXI. They also had the fastest torpedos (travelling at 49-50 kn at 9900 yards range or 13200 yards at 45 kn having the largest warhead of submarine torpedos in WW2).

But.... since the Japanese battle doctrine did not factor in the offensive use of submarines in commerce warfare, they were not used very successfully sinking only app. 1 million tons. And even that was only due to the fact that early in the war American ASW capacities were stretched pretty thin.