Alternate German submarine developments.

Only two samples are detailed, hardly enough....which is why that "1946 doc" dismissed it as only potential.
 
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Wolf1965

Donor
I am not sure if that came up, but the so-called "Kreislaufdiesel" (air independent diesel). They use oxygen (either LOX or pressurized) to run the diesel engine under water and dilute the oxygen with exhaust gasses. This gives a rather good range and avoids the dangers of H2O2. They are a bit noisy, but this was a lesser problem during WW2.
 
As I already pointed out WW-II ASW SWEEP rates are minimal based on ASDIC alone and most historic results depended on spotting surfaced subs. Once the sub submerges its next to impossible to find submerged.


13.1.2 Surface Craft Search Submerged Submarines
The role of surface craft in searching an area is limited by their small sweep rate. Visual and radar detection ranges are shorter than for aircraft, and the speed of the ship very much less. Table 6 presents a



TABLE 6. Sweep rates under various conditions (in sq miles per hour).

Surfaced sub Submerged sub

Aircraft
Visual (good visibility) 1,250 Approx 0
Radar - ASG 2,500 Approx 0
MAD 25* 15-20*
Sono-buoys 200* 15*

Surface craft
Visual Approx 0 Approx 0
Radar 100 Approx 0
Sonar 15


--141--
comparison of typical aircraft and surface craft sweep rates. Visual search by surface craft is not likely to be effective since the submarine can almost invariably see the surface craft in time to dive before the surface craft sees it. This visual search has purely hold-down value and is not effective in an offensive sense. Radar search by surface craft under low visibility conditions may, on the other hand, be expected to lead to contacts on any surfaced submarines unless they are fitted with search receivers and dive upon being approached. For surfaced submarines, however, the surface craft have a considerably smaller sweep rate than aircraft, so that the chief role of surface craft is conducting searches for submerged subs, a task for which aircraft are not effective.

The sweep rates for aircraft using magnetic anomaly detectors [MAD] or sono-buoys in hunting submerged submarines are about the same as that for surface craft using sonar, according to Table 6. The comparison is not a completely fair one, however. In the first place, the aircraft figures are based on trial results and have not been completely substantiated by operational data. Operational experience has indicated that classification of MAD and sono-buoy contacts is particularly difficult. In the second place, neither of them gives an accurate determination of the submarine's position but only a general indication of its presence, and it is difficult to make an effective attack on contacts of this type.

The primary task of surface craft in area search is thus sonar search for submerged submarines. Such search can be effective only if the submarines are concentrated in a small area, since the surface craft sweep rate is so small. To search an area 100 miles square with five ships requires about 6 days, whereas a single aircraft can search the same area for surfaced subs in 4 hours. Accordingly there are relatively few circumstances in which surface craft can be employed profitably for area search.

This is why most NATO navies opted for helicopter dipping sonars to combat the ever evolving threat of WARPAC subs.
 

McPherson

Banned
Still NSA. One needs to read within the times, means to hand and scrap one's preconceived and narrow biases and prejudices or wrong assumptions to understand what is presented. IOW, the later the research and more balanced, the more complete, but first look and original sources gives a contemporary read of what they at the time thought they knew. It is not what the reader assumes (^^^^).

Have to junk the bias and plainly READ what the authors write. (Again ^^^^.). They had air search, relied on HUFF/DUFF and radar to localize and then they used sonar to hunt after they drove the contact down. The U-boat is making 2-6 knots underwater, the planes dropping sonobuoys making 100 knots, and the destroyers driving the U-boat into the cloverleaf patterns herding the U-boat along at 6-10 knots. The search they need to cover after they drive down the WW II U-boat is ridiculously small. Patently obvious.

Modern subs are faster, so the search is a bit more involved.

IOW, you might want to read it again and try to understand what THEY KNEW THEN in light of the immediate above. (Italics)
 
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First, I haven't waded through this whole thread. In terms of commercial/cargo subs they only make sense IMO if used for high value cargos. Alloying elements for steels needed for high strength components and cutting tools would be one example. Pharmaceuticals is another. Shell companies in neutral powers using surface vessels could most likely move more material. In terms of combat vessels, more efficient sensors, better torpedoes with homing systems and range and better underwater endurance come to mind.

Another option that came to mind in the old Red Tide 1945 Yahoo group was the use of subs to do rocket attacks on surface or shore based targets using versions of the land based solid rocket bombardment weapons various nations used. Think the racks of rockets mounted on U S Navy amphibs in WW2. Such a weapon system if workable could be used by say the US to conduct raids on Jananese island based airfields with out employing the use of a naval task force.
 
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Another option that came to mind in the old Red Tide 1945 Yahoo group was the use of subs to do rocket attacks on surface or shore based targets using versions of the land based solid rocket bombardment weapons various nations used. Think the racks of rockets mounted on U S Navy amphibs in WW2. Such a weapon system if workable could be used by say the US to conduct raids on Jananese island based airfields with out employing the use of a naval task force.

IIRC a few US subs did fire some rockets at mainland Japan in 1945. Of course by this time the IJN had few ships to counter such a strike and both the IJA and IJN had few aircraft to try and interdict such an attack. Such an attack against an enemy that could put up ASW ships and aircraft would be risky at best...
 

Onlooker

Banned
Surcouf style cruiser submarines would be an excellent early war design. Majority of targets early war were sunk using deck gins, and ability to engage destroyers at ranges far exceeding those of said destroyers, the ability to engage them in surface combat and come out on top would force Britain to drastically change its anti submarine tactics as well as dedicate far more heavy ships into convoy escort duty, leaving them vulnerable to a greater degree to Bismarck style sally of capital raiders. Then naturally as war progressed type XXI style subs should start taking over
 

McPherson

Banned
Surcouf style cruiser submarines would be an excellent early war design. Majority of targets early war were sunk using deck gins, and ability to engage destroyers at ranges far exceeding those of said destroyers, the ability to engage them in surface combat and come out on top would force Britain to drastically change its anti submarine tactics as well as dedicate far more heavy ships into convoy escort duty, leaving them vulnerable to a greater degree to Bismarck style sally of capital raiders. Then naturally as war progressed type XXI style subs should start taking over

Actually makes some sense. At least gives a Makin raid type capability, too. Long dive time is a drawback though.
 

Onlooker

Banned
Actually makes some sense. At least gives a Makin raid type capability, too. Long dive time is a drawback though.

Not really an issue for submarines intended task. This is a long range submarine, far from land based aircraft which would require a fast dive, and one with ability to engage targets at 31.5 kilometers with its heavy cruiser class guns capable of piercing any ship below that class, able to lob 130kg projectile every 10 seconds from just one barrel. Make that 10 rounds a minute downrange. Couple that with regular submarines doing reukar dukes, and surface raiders now more free to engage targets or at least scare the bejesus out of the Brits and you get a winning combination.
 

McPherson

Banned
Not really an issue for submarines intended task. This is a long range submarine, far from land based aircraft which would require a fast dive, and one with ability to engage targets at 31.5 kilometers with its heavy cruiser class guns capable of piercing any ship below that class, able to lob 130kg projectile every 10 seconds from just one barrel. Make that 10 rounds a minute downrange. Couple that with regular submarines doing reukar dukes, and surface raiders now more free to engage targets or at least scare the bejesus out of the Brits and you get a winning combination.

Practically, and the French learned this the hard way with Surcouf, the cruiser sub's 15.5 cm guns' range was cut to less than in half and so was the effective fire rate. Has something to do with hull roll, pitch and yaw. A sub is not a very good gun platform. So, a Tribal could easily close and probably swiss-cheese a cruiser sub from 15,000 meters out to 12,000 meters in about 2 minutes with her own 12 cm guns barking salvoes of 50 or so shells aggregate per minute total as ladders well within their guns' effective range from the four barrels (12-13 RPM per barrel). Might want to be able to dive before that happens? Just sayin'.
 

Onlooker

Banned
Practically, and the French learned this the hard way with Surcouf, the cruiser sub's 15.5 cm guns' range was cut to less than in half and so was the effective fire rate. Has something to do with hull roll, pitch and yaw. A sub is not a very good gun platform. So, a Tribal could easily close and probably swiss-cheese a cruiser sub from 15,000 meters out to 12,000 meters in about 2 minutes with her own 12 cm guns barking salvoes of 50 or so shells aggregate per minute total as ladders well within their guns' effective range from the four barrels (12-13 RPM per barrel). Might want to be able to dive before that happens? Just sayin'.

Surcouf and alternatively even bigger, 12 inch gunned HMS M1 were the designs of 1920s. Deck awash and only gun above water proved as a good firing platform in M1. If cruiser subs were pursued it is highly likely they would have seen and benefited from technological improvements. Type IXD Uboat was just 15 meters shorter and had excellent diving speed and depth far exceeding the 80m of surcouf at 230.
 

McPherson

Banned
Surcouf and alternatively even bigger, 12 inch gunned HMS M1 were the designs of 1920s. Deck awash and only gun above water proved as a good firing platform in M1. If cruiser subs were pursued it is highly likely they would have seen and benefited from technological improvements. Type IXD Uboat was just 15 meters shorter and had excellent diving speed and depth far exceeding the 80m of surcouf at 230.

I can also support the similar findings with the US experience with Argonaut and Nautilus, more modern V-cruisers and generally superior examples with operating characteristics about equal to even the later Type IX U-boat. This is not going to change RTL results for too much gun for the sub or the slow dive times for huge (by the standards of the day) subs, not even for the Germans or the Americans. There are just too many rigid engineering and marine factors that make it so. Handwavium is not going to work. One has to deal with the limits.
 

Onlooker

Banned
I can also support the similar findings with the US experience with Argonaut and Nautilus, more modern V-cruisers and generally superior examples with operating characteristics about equal to even the later Type IX U-boat. This is not going to change RTL results for too much gun for the sub or the slow dive times for huge (by the standards of the day) subs, not even for the Germans or the Americans. There are just too many rigid engineering and marine factors that make it so. Handwavium is not going to work. One has to deal with the limits.

Agreed. But one should not tie issues of 1920's to late 30's potential subs. If one judged tanks on interwar design plenty of them could be dismissed as pointless drivel
 

McPherson

Banned
Let's stick with subs. Tanks have an altogether different set of characteristics. If we look at what the Germans, British and Americans did, arguably the best submarine users of WW II, we can quickly see that each of them either picked a destroyer gun or a naval howitzer to arm their boats. About 3.5', 4' to 5' and generally 50/40/ or in the American's case a 25 caliber gun. These were not intended to slug it out with a cruiser or a destroyer. Plonk an armed merchantmen or finish off a torpedoed adversary was the intent. None of the three built a WW II cruiser gun armed sub. They used what they had and were careful to pick their spots so as to not expose their cruiser subs to enemy fleet destroyers in a surface gunnery duel. It was because of the limitations imposed on their naval artillery by the subs which carried it.

P.S. The one other power who were an efficient user of submarines, the Dutch, also used the 3.5 in (8.8 cm) gun as described. I include them because I'm getting an education on them right now.
 
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My thought was night attacks against isolated atoll airfields. One or two fleet boat are less assets at risk. If the launch racks are neutral buoyancy and can be dumped once fired. The question is how the sub behaves when surfaced. Say 60 rockets equivalent to a 6 inch she'l would be a hell of a surprise at 3 am
 

McPherson

Banned
My thought was night attacks against isolated atoll airfields. One or two fleet boat are less assets at risk. If the launch racks are neutral buoyancy and can be dumped once fired. The question is how the sub behaves when surfaced. Say 60 rockets equivalent to a 6 inch she'l would be a hell of a surprise at 3 am

This was actually done by a couple of US boats off Japan in 1945. It would not be prudent in an area with strong ASW defenses.
 
Still NSA. One needs to read within the times, means to hand and scrap one's preconceived and narrow biases and prejudices or wrong assumptions to understand what is presented. IOW, the later the research and more balanced, the more complete, but first look and original sources gives a contemporary read of what they at the time thought they knew. It is not what the reader assumes (^^^^).

Have to junk the bias and plainly READ what the authors write. (Again ^^^^.). They had air search, relied on HUFF/DUFF and radar to localize and then they used sonar to hunt after they drove the contact down. The U-boat is making 2-6 knots underwater, the planes dropping sonobuoys making 100 knots, and the destroyers driving the U-boat into the cloverleaf patterns herding the U-boat along at 6-10 knots. The search they need to cover after they drive down the WW II U-boat is ridiculously small. Patently obvious.

Modern subs are faster, so the search is a bit more involved.

IOW, you might want to read it again and try to understand what THEY KNEW THEN in light of the immediate above. (Italics)

IF this was meant to clarify anything -it failed miserably. You must yield to the findings of the time. I can't begin to imagine this phantasy scenarios of sonobuoys patterns dropped in coordinated fashion with destroyer dashing to achieve the impossible results on a fleet wide basis.

You need to climb down from you singular examples and embrace the real war.

To accurately predict battle results is the most complex modelling, and needs hundreds of examples to approach that.
 
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