Technology and Operations  
This forum is for discussing technological & operational matters pertaining to U-boats. 
US vs German subs
Posted by: Kurt ()
Date: September 24, 2000 09:05PM

You have asked a very interesting, complex, and controversial question. It is not a easy one to answer, nor are there definitive answers. I'll confine myself to the German and US boats, the ones I know best.

Comparing the US Gato fleet boats to the German VIIC compares the types that did the bulk of the fighting for the two navies. (Though the German type IXD2 is more comparable to the Gato in size - that doesn't change much the conclusions of my post).

First, let's compare the boats general surface characteristics. The Gato class was generally superior to the VIIC on the surface. Its greater size meant higher speed, greater range, better crew habitability, and a more stable gun platform.
The flexibility and robustness of the 4 engine indirect drive system of the US Gato's made engine failure caused aborts much rarer than in the direct drice, 2 engine U-boats. The longer range was a big advantage: even without milch cows or mid-ocean refueling (routine with U-boats) rarely did Gatos with torpedoes aboard and targets waiting head home because of a lack of fuel, a common problem with the VIIC: it was just too short ranged for the Battle of the Atlantic. On the other hand, surface gun actions by subs (apart from US plinking at fishing sampans - a widespread habit, especially in the later war years) were rare in WWII. And, despite air conditioning, and better crew quarters, the US crews had harder times completing their generally shorter patrols. They suffered more often from rotten food or spoiled water. The bigger US boats had bigger profiles, making night surface attacks harder (before radar made this difference moot). So give the surface characteristics to the US boats, but with reservations.

Under the water, the German boats take the lead. The smaller VIIC had greater maneuverability, quietness, and greater diving depth. But, though greater depth seems a good advantage, it was actually more important to be able to submerge quickly than deeply. Most U-boats were destroyed on the surface or just under it, not at great depth. But still, the VIIC could submerge quicker than a Gato, but not by much: a well trained crew could get a Gato under in 35 seconds, vs maybe 20 or so for a U-boat. 'Under' was 60 ft for a Gato, and 45ft for a VIIC, due to the different sizes of the boats. Give this edge to the VIIC.

As for weapons, the German torpedoes were clearly leaders. Though both sides struggled with torpedo problems, no one equalled the plethora of problems, and beauracratic inertia in solving them, of the Americans. US subs had torpedoes that broached, were duds, ran under targets, even circled, with desparing regularity. Their warheads were smaller. American electric torpedoes, a copy of the German version, lost something in the translation, and was full of problems. The US acoustic sub torpedo, the 'cutie', just plain didn't work, while the German T-5, well, sometimes worked. (Not to be confused with the US 'Fido' air dropped ASW acoustic torpedo, that proved VERY deadly against U-boats - US subs never used this weapon).

As for mechanical systems, again a clear German lead. German sonar, optics (periscopes), machinery, from hull construction to engine design, was ahead of the Americans. The Germans even had schnorkels, though in reality the schnorkel was not very useful. A sub using a schnorkel could only make 4 or 5 knots and was blind (periscope and sonar unuseable).

There is only one last category, but in some ways, the most important: electronics. Here the US boats enjoyed a huge, decisive, and commanding difference. US boats were equipped with a variety of radars, radar detectors, jammers, and communication devices that U-boaters could only dream of. At a time when U-boat commanders were struggling with makeshift detectors (that didn't work) made from wood, string, and wire, US boats sported a veritable forest of antennas off of their periscope shears. While U-boats were always at the electronic disadvantage to allied ASW, the opposite was true of US Gato boats fighting the Japanese. When many allied ASW ships had radar, Doenitz still claimed radar was impossible to mount on ships (let alone aircraft). When Allied ships were using direction finding to home in on U-boat radios, Doenitz claimed this was impossible. But most of all, the US boats had highly effective radar (the SJ) and very effective radar detectors. This offset all the disadvantages above, including slow diving times (radar gives better warning times), bad optics (use radar in attacks), etc. Towards the end, US boats even got the ST periscope mounted radar - one radar 'ping' and you have the exact range to the target - far offsetting any disadvantage in night attack scope design, and taking the guesswork out of attack solutions. And, of course, the US boat's radio codes were not compromised, while the U-boat 'Ultra' was read with increasing ease as the war dragged on. Many, (most?) U-boats were defeated electronically, by enigma intercepts, direction finding on radio emissions, or radar detection. The allies' complete mastery of the electromagnetic spectrum over the U-boat is the major reason for their defeat, a huge factor in the US subs victory over Japan, and the major difference between the US boats and the U-boats in combat effectiveness.

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Subject Written By Posted
Quality of submarines bernard zimmermann 09/21/2000 09:47AM
RE: Quality of submarines David W 09/21/2000 11:18PM
RE: Quality of submarines - RN vs VIIC Andrew Hetherington 09/22/2000 11:01AM
RE: nautical mile conversion AL Wellman 09/25/2000 01:24AM
RE: nautical mile conversion Andrew Hetherington 09/25/2000 07:29AM
RE: Admiralty mile AL Wellman 09/25/2000 06:13PM
RE: nautical mile conversion Steve Cooper 09/25/2000 01:15PM
RE: nautical mile conversion Andrew Hetherington 09/25/2000 03:09PM
Max depth US subs Don Baker 09/26/2000 08:54PM
RE: Max depth US subs Forest 09/27/2000 12:14AM
RE: Pressure Testing Submarine Hulls Don Baker 09/27/2000 04:42PM
Re: RE: Pressure Testing Submarine Hulls stan 06/17/2012 04:33PM
RE: Max depth US subs kurt 09/27/2000 04:34PM
RE: Max depth US subs David W 09/28/2000 01:39AM
US vs German subs Kurt 09/24/2000 09:05PM
Underwater manueverability David W 09/25/2000 11:31PM
RE: Underwater manueverability Forest 09/26/2000 01:31AM
Re: US vs German subs Colin Fulton 01/28/2016 12:29AM
Re: US vs German subs SnakeDoc 01/28/2016 08:46AM
Re: US vs German subs Jim 02/23/2018 05:44AM
Re: US vs German subs TF 02/24/2018 04:42PM
RE: Quality of submarines bernard zimmermann 09/25/2000 10:32AM
RE: Quality of submarines kurt 09/25/2000 08:58PM
Re: RE: Quality of submarines horst 03/31/2018 05:23AM
RE: Mk24 and "Cutie" Don Baker 09/26/2000 05:04AM
RE: Mk24 and "Cutie" Steve Cooper 09/26/2000 12:10PM
RE: Mk24 and "Cutie" joe brandt 09/26/2000 03:56PM
RE: Mk24 and "Cutie" Don Baker 09/26/2000 09:16PM
RE: Mk24 and "Cutie" kurt 09/26/2000 08:59PM
RE: Mk24 and Cutie Performance Don Baker 09/27/2000 08:29PM
Correction to Cutie performance Don Baker 09/28/2000 01:02AM
RE: Mk24 and Cutie Performance kurt 09/28/2000 04:07PM
RE: Hellions of the Deep Don Baker 09/30/2000 02:26PM
RE: Hellions of the Deep Forest 09/30/2000 04:22PM
TBM/TBF Avenger Don Baker 09/30/2000 06:16PM
Re: RE: Hellions of the Deep ROBERT M. 06/26/2012 06:06PM
Re: Quality of submarines Walter Schmidt 06/26/2012 03:02PM
Re: Quality of submarines ROBERT M. 06/26/2012 05:50PM
Re: Quality of submarines Walter Schmidt 06/26/2012 08:36PM
Re: Quality of submarines ROBERT M. 06/26/2012 08:52PM
Re: Quality of submarines Walter Schmidt 06/27/2012 08:46PM


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