As an avid war gamer/history buff, I would like to see a game designed too allow for 'what ifs' to be included. I would love to see this one played out!

For background, German Industrialists anticipate a new World War. In preparation (circa 1920-1930), a team of aircraft engineers & naval ship designers are sent to japan to lend German perspective & gain Japanese practical experience in these fields(thus allowing Germany to prepare plans for more modern versions of aircraft and warships). Particular emphasis being placed on submarines, seaplanes, steam catapults, and submersible barges. If such a venture were funded from non-government sources(say a group of wealthy industrialists), Germany's economical and political difficulties of this era would be no bar. By mid 1930's plans are complete and Germany begins gaining practical experience with these new technologies. By 1940, The modified submarine fleet is deployed in the Atlantic, and the seaplanes await their orders...

Basically, this 'what if' pre-supposes that a group of far thinking German strategic planers, well in advance of the start of hostilities, put submarines and aircraft together(as the army did with the use of massed tanks/ground support aircraft for the 'Blitz' plans) to forge a new weapon of war. The plan would be to build an initial force of about 300 military seaplanes(capable of carrying 4 torpedoes each), flying at least 150 MPH, and have a total range of at least 600-700 miles. The seaplanes(larger cousins to the American PBY) would be able to fly out to sea, land on the surface, motor astride a partially submerged U-boat/barge, and then be re-fueled, re-armed, and swap crews(the submarines/barges would be their spare crew quarters, fuel tanks, and armaments magazines).

Submarine tactics/capabilities:
Spread out to locate convoys, radio location-course-speed & trail. Other submarines receive info, and mass for concentrated attack. Attacking subs evade escorts, penetrate the convoy and make attack.

Submarine problems:
Slow speed, so only a handful of subs would be able to engage a particular convoy. Vulnerable to counter attack, basically defenseless while avoiding the depth charging by convoy escorts(and completely incapable of making additional attacks while doing so). And having to catch up too the convoy afterwords. This meant that only a small part of the deployed subs even got to make an attack on a given convoy, often only being able to attack the convoy one time before being driven away.

The modifications to the submarines would be no conning tower, a steam catapult the length of the sub, and the ability to tow 1(or more) submersible supply barges. The tactical improvements would be dramatic. The submarines no longer have to close with the convoys and risk being sunk by escorts.

Seaplanes tactics/capabilities:
The seaplanes, flying 10,000 feet above sea level at 150 MPH, have a much increased chance of detecting a convoy, so the chances of a convoy not being detected is reduced to practically nil. The seaplanes could attack any convoy within 150 mile radius of the sub (and with multiple, dispersed subs, this covers virtually the entire north Atlantic). Using the seaplanes, the entire force could mass for an attack on any convoy. If the convoy were an hours flight from the subs, the seaplanes raids could fly out, spend an hour orbiting/attacking, fly back to the subs (or to other subs ahead of the convoy), re-fuel/re-arm, and repeat. Under ideal conditions, the seaplanes could make 2-4 raids a day, while still allowing the subs to stay well out of harms way.

The material cost to the German war effort (building an initial force of 300 seaplanes instead of 300 land based planes), and configuring the subs as seaplane tenders (which the Japanese had), would be negligible. Had the Germans had such detailed plans/forces developed in time for the war...

[ 29. November 2006, 09:50 AM: Message edited by: Otto ]

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I can see a number of problems with your 'what if' question.

The German Navy and German Air Force had very little to do with each other. The navy would have to spend money on aircraft instead of ships or U-boats. In the 1930's money was in short supply due to the depression.

The Atlantic ocean is not as calm as the Pacific and sea planes would not last long in the waves and storms of the Atlantic.

Navigation over the ocean was not that great in WWII and finding a submarine in the ocean would be difficult. The sub could send radio beams to navigate by but the Royal Navy could also home in on the beams too. The Royal Navy had carriers and the Germans did not.

Taking a seaplane apart on the ocean and then putting it back together in the ocean is time consuming and dangerous.

I think the biggest problem is the lack of coorperation between the German air force and the German Navy over resourses and how to run the war.

Welcome to the forums !

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Thanks for the speedy reply!

Your correct that the airforce and army were very much closer to Hitler's heart. Then again, the navy never came to Hitler and said "we got a great new way to wage a war at sea, and you don't have to spend years building lots of costly battleships to win. Given the amount of money being spent at the time, I don't think this would be a problem, as the aircraft and subs were alreadly being built anyway.

My 'what if' doesn't call for more planes/subs, just different ones. Also, the Navy commander (Reader I think), was planning for war only after Germany had build the famous 'Z' plan, and that would have taken years and alot more reasources.
Again, had the navy had someone able to bring Hitler around to this idea (which would have been vastly more cost effective), it would have been possible.


One of the reasons too have multiple, dispersed groups of submarines would be to allow the seaplanes to avoid the storms. If sub groups A and B are in stormy areas, seaplanes would divert to sub group C. Given the ability to thus avoid all but the worst storms (the seaplanes could always just head for shore if it got too bad), I don't think this would hinder their operations in the 3 months it would take them to win the war, namely July-Aug-Sep 1940.


Exactly! And the British did exactly that. One of the factors mostly overlooked today, the German navy had no way of knowing what the weather was like in the N. Atlantic, and were thus forced to have their submarines make radio transmissions reporting on just that. This fact was of enormous advantage to the brittish code breakers, as weather reports always had the same format, and gave the subs position away. If aircraft had been able to make these weather reports, no subs would have been forced to give up their locations.

As for the British carriers, they would have them just exactly long enough for one battle. Unlike the American and Japanese carriers of the day, the British carriers were still using bi-planes.

If the germans had 25 squadrons of 12 planes each(figure 5 scout/recon squadrons, and 20 strike squadrons). Say on any given day 40% were availible. This would give the Germans 24 scouts and 96 torpedo bombers. Facing them would be (at most) 3 British carriers. I doubt that the British could mass their carriers fast enough (or at all) to put more than 3 in the same battle.

So, possibly 60-90 antique bi-plane fighters, getting to watch their carriers being torpedoed and then having to ditch in the sea. Even granting the Impossible and say the Brit fighters managed to down an entire squadron per carrier sunk, the British would not be able to replace those carriers, and the Germans could very easily replace 36 planes! The beautiful thing about a seaplane, it's flightdeck is the ocean surface, and is unsinkable.

Given these conditions, the German navy would have control of the sea in short order. And given that after the first strike, the remaining torpedo bombers would return and finish the job without fighter opposition. Surface ships would be so much meat marching to the slaughter.


I said nothing about taking them apart. [img]smile.gif[/img]


Personality conflicts in the german command structure apart(what if), i wonder how long it would take to starve the British into surrender?

Thanks!

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Its not hard to do with the older manual boardgames. Even decompiling computer based game does not ensure you can easily find the data you wish to change. This is a major, major weakness of computer based games; the lack of ability to analyze the algorythims used in their play. But, of course, usually these are so bad and detached from reality beyond the techincal level of strategy they can be summarily dismissed as irrelevant to historical accuracy.

There was some exchange of information between Germany and Japan, mostly in Japan's favor. The Germans were more than a bit dismissive of Japanese technology, as was much of the West. In technical details, the Germans were ahead of Japan in shipboard technology. The Japanese had not widely adopted welding, diesel engines, high pressure steam plants, and had inferior armor quality.
The steam catapult was unknown at this time. Catapults were either impulse (fired by a black powder or guncotton charge), hydraulic, or mechnanical.

It has already been noted that landing in the Atlantic will be difficult at best. Conditions rarely allow for this and certainly will not on a regular basis.

This was Donitz' original scheme using wolfpacks.

This was why Donitz wanted the subs to attack on the surface where they had a 18 + knot speed and could in many cases outrun escorting ships. The problem for the Germans was that technology overtook the plan, particularly radar.

Being lower in the water a submarine is more vulnerable to flooding through hatches. Exactly where is a submarine with diesel engines going to get steam? Are you suggesting a regression to the ill-fated British K class of WW 1? A submersible towed barge would require some sort of remote control for flooding as well as connections for compressed air (to deballast and surface) along with a number of other technical details complicating their use.
Having to remain for long periods on the surface during the day would actually increase the submarine's vulnerability to detection and attack from Allied patrol aircraft. The presence of a slow submerging barge and possibly aircraft in the process of refueling and rearming also increases the vulnerability. Even if the sub does manage to evade by submerging the aircraft sitting on the surface are now sitting ducks for destruction.

And, with the increased air threat and decreased submarine threat the Allies would more quickly ensure their ships had better air defenses. The flying boats would be very vulnerable to defending fighters and, since attacking ships successfully can only be done at low levels they are vulnerable to AA fire as well. Even a damaged aircraft is likely to be lost so far from home without repair facilities. Flying relatively slow and at the altitudes suggested also implies that by mid 1940 they will almost certainly be detected by naval vessels on radar long before they can close to visual distance.

Building 300 large seaplanes will be a significant drag on the German aircraft industry. Look at their original production figures. The Japanese had no submarine based seaplane tenders. Yes, they had several classes that carried a small float plane for scouting that was used occasionally, and there was the larger I 400 class with 3 float planes each for attacking the Panama Canal that first came into service in 1944 but these were not tenders by any stretch.
Another problem for the Germans was that the Japanese boats were far larger than any prewar U-boat. The Type VII is a very small submarine and the Type IX is not that much larger. On the whole, I don't see this as a workable or desirable alternative.

Thanks for the reply!

I didn't know that! Which kind of catapults were the most common? Which were the most powerful? I do know that the Japanese built better naval aviation aircraft, and better torpedoes. Also, the primary benefit would be to get working prototypes and work out the bugs in Japanese home waters. Once the Germans had practical experience mating seaplanes to submarines, they could begin production.

I have to say that I don't buy the weather being able to completely shutdown the seaplanes. Simply avoid the storms. I can't imagine the entire North Atlantic having storms everywhere. Where the seas are too rough, head too the rest of the ocean not having storms. If some convoys are sailing through rough seas, you attack the other convoys that are not! There would almost certainly be some place (on any given day) where the 'weather permitting' would be true.

This misses the point, any threats too the seaplanes would be MORE of a threat to the subs. So the subs could sometimes escape on the surface (mainly at night), but the seaplanes would be over 100 knots faster, and could easily break contact (In minutes, not hours), and be back again within a few hours.

And despite this, the subs operated succesfully in the stormy N.A. throughout the war. My plan would have the subs in the clamer areas. I should point out: I do not think the British would have been able to last till winter 1940 (the stormiest weather months). I think that the torpedo bombers would give Germany the ability to fight a 3 month 'Blitz' and sink such vast numbers of merchant shipping as to force British capitulation well befor dec 7, 1940. A full year befor pearl harbour!

I planed to have crews in each barge with generators/battery backup like the subs, just not as powerful (the barges would be power self-sufficient in all respects save propulsion)


What 'allied patrol aircraft'? I would never deploy the submarines within range of land based allied aircraft, because they would be sitting ducks.

Keep in mind that until the deployment of US 'Escort carriers' later in the war, there always remaind a gap in allied air cover. In the summer 1940, this gap would be huge! This is where Donitz successfully deployed his wolf packs.

Again, assuming the allies had ANY air cover, it would have to be carrier based, not land based. Keep in mind the usual wartime routine of sending your scouts out well before dawn, so that at dawn, they are on station. A carrier battle group or convoy is going to be spotted long befor a couple of slow moving/stationary subs. And even if you spot them, you still need to be able to get your air strike in befor they submerge (and meanwhile, they are gunning for your carrier, which cannot submerge).

Even in the last days of the war, AA fire was not capable of driving off/smashing air attacks. Yes, better AA would mean more planes shot down (on average), but considering the tradeoff (100,000's of tons of allied shipping vs some aircraft), that is a winning strategy for Germany. And considering the historical tradeoff of subs for merchant tonnage that almost worked...

While that is true, again there will not be 'defending fighters' after the first raid, as British carriers didn't have modern aircraft in 1940 and definately wouldn't be able too fight off scores of torpedo bombers, and once those carriers are hit, it's all over. AA fire never shot down as many aircraft as fighters, and given the time frame (three short months), I doubt any amount of additional AA armament would make a difference.

Not all allied ships had radar, but granted that almost all convoys/task forces would have at least one radar equipped ship: Seeing the aircraft on radar, is not the same a stopping them. Nor surviving the raid.

I don't know where to find that. However, they had 3,000 aircraft by the BoB, yes? I think that fighting the British at sea (where their only aircraft were few and far between/antiques), would be much more sensible than fighting them on their home turf.

I guess I should say: not in the sense of having a sub long catapult throwing the plane aloft. However, they did use submarines to haul parts/fuel for seaplanes to the different island garrisons. If a tender means extending the operational capabilities, then they did have that. If tender means arming torpedoes, launching the seaplane, then they didn't.


I do believe that weather and personality conflicts notwithstanding, this change in strategy would be both workable and very desirable. I don't recall the # of U-Boats built and lost in the war, but consider this: every U-Boat lost (and replaced) would be more than the cost or replacing a 12 plane squadron of seaplane torpedo bombers. Every 12 plane squadron of seaplane torpedo bombers is going to sink allot more merchant tonnage than a single sub. As Germany is loosing planes, the allies are loosing ships! You cannot ask for a better return than that!

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I would not be too quick to dismiss Swordfish and Sea Gladiators as old biplane aircraft. The Germans and Italians did so and deeply regreted doing so. Most of the German heavy ships at the time also had biplanes for recon and range finding.

Can you give an example of the type of seaplane or flying boat you had in mind for the submarines ? I would guess it would have to be big, multi-engine, and very sturdy. The Germans had the Blohm Und Voss Bv-222 and Bv-238 but they were huge and would cost a fortune to build 300. The Bv-138 was a good design but could not carry four torpedos, unless they were of reduced size.

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As far as interception: Whether the British have Skuas, Fulmars, or Martlets (US Wildcats) on their carriers so long as they have decent radar the strike is doomed.
One can look no further than the Pacific war to see that unescorted poorly armed (and in many cases fairly well armed) bombers (flying boats in this case) are going to get thoroughly worked over long before they arrive on target. At just a 30 mile interception point from the target the Germans could reasonably expect to lose 60 to 70% of a 12 to 15 plane strike to a 4 to 6 plane CAP (see Methods of Operations Research pg 89 to 92 paras 5.2.9 - 5.2.11 by Kimbal and Morse for a analytical model for example).
As for AA, by the end of 1943 Allied AA at sea was getting to a point where it alone was overwhelming.
The outstanding example of this potency was the Battle of Empress Augusta Bay on Nov 2 1943 when Admiral Stanton "Tip" Merrill leading a force of four US light cruisers and four destroyers was attacked by just shy of 100 Japanese G4M "Betty" bombers out of Rabaul carrying a combination of bombs and torpedos. This is a force larger than that that sunk the Prince of Wales and Repulse.
Unlike the British the US ships drew up in a tight circular formation. They opened fire on the Japanese firing a total of over 1000 5" shells (many were VT fuzed) and over 13,000 40mm and 20mm rounds. Over a third of the attacking Japanese bombers were shot down, the vast majority of the rest suffered some degree of damage. The Japanese managed one bomb hit causing knocking out a 5" mount on a light cruiser and killing 5 crew.
From Coral Sea on, the combination of a fighter CAP directed by controllers onboard ship using radar was a virtually unbeatable combination. By Midway the Japanese were taking 60 to 80% strike losses.

On another note: Of the original German seaplanes and float planes available from about 1936 on none are really suitable for the mission you describe. The Bv 138, ostensibly the most modern and widely used, suffered almost 4 years of engine problems many serious in nature. The use of diesel engines on this aircraft also limited its useful service ceiling to about 16,000 feet max. It also could not have lifted two torpedos and its normal bombload was a meer 440 kg in 110 kg bombs. While the He 115 could lift a single torpedo it lacks the range you want and is extremely vulnerable to fighter opposition having a defensive armament of just 3 7.92mm machineguns.
Of the big multi-engined seaplanes like the Bv 222 or 232 that TA152 mentions less than a dozen were built at a rate of just 2 or 3 per year.

I knew nothing about the German seaplanes! [img]smile.gif[/img]
I envisioned a plane w/4 (oversize) engines. A large enough wing to support long flights w/torpedoes (either within a Bombay or under wing). Not sure if under wing floats were in use then or not?

When I read about the German navy trying to close the Atlantic with just subs, and knew there HAD to be a better way. Not being a Navy man, i had never heard of any catapults other than steam. If the Germans had conferred with the Japanese, I'm sure they would have built 'float' fighters as they did. A seaplane fighter my not be as nimble/fast as a Land based fighter, but would have to at least be a match for the Brit carrier based planes.

The Brit carriers planes enjoyed the successes they did, because they had no opposing air, right?

I had (2) Idea's I didn't post about the seaplanes earlier, one was either piggybacking(or flying and refueling along the way) a (twin engine) float fighter out to the combat area. And the other was for something like an anti-aircraft suppressor variant. I think I got the idea of the piggyback from seeing a picture of what the Germans were doing in desperation against the B-17's.

When the Bombers would leave the land for deployment, some would takeoff with a fighter mounted on the back. This would allow the float fighter to be brought at least out to the combat area without having to land at sea to fuel several times. I don't think anyone would want to try to land a seaplane (in any weather conditions) with a float fighter strapped on the back.

As for the AA suppressant version, would a 20mm armament be heavy enough to allow strafing runs to be effective? Or would you want something heavier? From building models, and looking at photographs, I see that most AA armament were open emplacements. Warships had DP guns in twin mounts that would also be used for AA, and these couldn't be suppressed.

However, if you strafe the bridge of the ship (and generally along the upper-works) at the same time your torpedo planes are making their runs, this should hinder the lockouts, conning personnel, and many of the unprotected AA gunners.

I also envisioned the attacks going along these lines: A pair of strafing aircraft come in from dead ahead, raking fire from the bridge, and down along either side. This to be repeated by additional pairs as torpedo planes come in from three directions. If a ship has dead/wounded/missing AA gunners, lookouts, & helmsmen, dodging the incoming torpedoes (from three directions) is going to be most difficult. Such tactics would have to be carefully rehearsed (like the training for the sub crews).

Can you (or anyone else) direct me too a website that has some good technical info on all the seaplanes pre/during WWII? As well as the Brit carrier aircraft? Things like range/load, speed/ceiling, and such? Also, the tech info for the various light mount (20mm) AA guns?

Thanks!

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We meet again! [img]smile.gif[/img]
I have too say thank you guys! I was beginning to think i was the ONLY one who was interested in WWII history. Now too find that there is not only a dedicated site, but peopled by others (many of whom obviously have knowledge far greater than my own), who are at least as interested as i am, well that rocks!


Please see my other post for possible fighter escort/AA counter.

(Is this work available on-line? I would like to read that myself if so).
What level of training does this model take into account? Does it for example take into consideration that the initial battles in this 'what if' would be taking place between Brit aircrews taken by (strategic) surprise? In being subjected to strong torpedo bomber raids out in the middle of the Atlantic, well beyond the suspected range of any German aircraft?

If not, how many months/years would it take the Royal navy to get up too speed? Keep in mind, given an initial starting force of 5 scout and 20 strike squadrons. Supposing a 40% initial deployment in late June 1940 thru end of September 1940 as the probable decisive period of this 'sea blitz'. The Germans would locate just about every convoy as sea, and be able to mass their forces for maximum effect. In the case of a carrier escorting a convoy/carrier battle group, I would expect the Germans to hit it with every bomber they could bring too bear, all at once!

Keeping in mind that the German aircrews would be fighting against opponents they were trained for (and expecting too) meet in battle, and that the Brits wouldn't be, I think the previous model my be a tad optimistic. Nevertheless, let us assume (for the sake of argument) that in this first encounter the Brits manage to down an entire squadron of the bombers. If the Germans hit the carrier with 'everything they had' that would be 90+ bombers.

Results: 12 bombers lost in Raid one, day one! Raid two, day one, remaining 80+ bombers (having finished the Brit carrier very easily in the first raid), return to and decimate the remaining warships, or just ignore the task-force and wipe a convoy. Raid three, day one, 80 or so bombers find and wipe next convoy. Day two, Raid one etc...

My expectation is that in the 92 days from July 1st thru Sep 30th, 1940 the Germans would be capable of destroying approximately 200 convoys/task forces! I do not have at my disposal the information on the exact tonnage of supplies needed to keep Briton in the war, but am confident that this 'sea blitz', even if the North Atlantic weather forced their total re-deployment into the Mediterranean Sea till spring, would have crippled (if not finished) Briton.

Questions: How many total carriers did RN have in summer 1940? Of these, how many were in home/N. Atlantic waters? How many in E. Med? India? Far east? I think it likely, that by the time of the Bismark setting sail, no RN capital ships would be left to oppose her except those kept in port.

Also, if the Germans had realized the (Strategic) potential presented to them by using this method, supposing a steady reinforcing of a squadron a month would not be beyond reason.

Quote:

Originally posted by T. A. Gardner: [QB] As for AA, by the end of 1943 Allied AA at sea was getting to a point where it alone was overwhelming.

That sounds allot like one the the dedicated AA research groups! Was it?

Quote:

Originally posted by T. A. Gardner: [QB]From Coral Sea on, the combination of a fighter CAP directed by controllers on-board ship using radar was a virtually unbeatable combination. By Midway the Japanese were taking 60 to 80% strike losses.

Cough! What?!?! [img]smile.gif[/img]

Quote:

Originally posted by T. A. Gardner: [QB]On another note: Of the original German seaplanes and float planes available from about 1936 on none are really suitable for the mission you describe. The Bv 138, ostensibly the most modern and widely used, suffered almost 4 years of engine problems many serious in nature. The use of diesel engines on this aircraft also limited its useful service ceiling to about 16,000 feet max. It also could not have lifted two torpedoes and its normal bomb-load was a mere 440 kg in 110 kg bombs. While the He 115 could lift a single torpedo it lacks the range you want and is extremely vulnerable to fighter opposition having a defensive armament of just 3 7.92mm machine guns. Of the big multi-engined seaplanes like the Bv 222 or 232 that TA152 mentions less than a dozen were built at a rate of just 2 or 3 per year.

My whole premise is that the Germans (Circa 1920) begin putting plans together for what they would need for this strategy too work. None of the actual seaplanes they produced were intended for the role needed, thus none of them were suitable for the role needed. Had this plan been properly developed, the Germans would have placed building, maintaining, and expanding their seaplane force on the top of their to due list. [img]smile.gif[/img]

If, however, they had thought of this plan (again, 15 years before needing to put the subs/seaplanes into production) could they have made them?

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Take a look in the section called Weapons in WWII, and then the aviation linkfest at the top. That should keep you busy for at least 10 years !!!

In the late 30's I don't think they had engines strong enough to lift a heavy seaplane/flying boat and four torpedoes, plus fuel and still be built strong enough for sea duty. Anouther problem for sea aircraft is salt water spray eats all things metal. Keeping the aircraft out to sea with no fresh water spray downs would make them very short lived for the investment.

There are a string of islands in mid Atlantic that belong to Portugal that the Germans could have taken for an aircraft base but I guess they did not think of it. (Portuguese are not too bright so taking them would be a push over.)
Can't get midget submarines to central Texas. [img]graemlins/sub.gif[/img]

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Thanks!

When I first thought of this Idea years ago, I had assumed that a 4 engine/4 torpedo craft would be optimal (multiple runs per raid). Keep in mind also, the seaplanes would be getting aloft (while loaded) by using the sub mounted catapults.

I forgot the fact that aviation was just starting out back then. If smaller aircraft would have been the best that could be made workable, say 2 engine/1 torpedo, then they would have to be cheaper (and thus more numerous) as well. I would also expect to see greater speed, as well.

Alas, the links didn't work for me...

I think that while there are some valid points raised in this thread, but i believe a workable force could have been deployed given the 15 years stipulated for research/development/testing in Japanese waters.

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Just looking at the seaplane:

Four torpedos weigh about 4 metric tons.
Fuel to lift this load and fly the distances suggested would be about 12 to 15 metric tons.
Since a defensive armament would be required, say several 20mm and 7.92mm or 13mm guns and ammo, add another 1 or 2 metric tons.
So, we are looking at a flying boat weighing in at about 30 to 40 metric tons (say 60 to 80,000 lbs) loaded.
Some flying boats that fit this profile include:
Consolidated PB2Y-3 Coronado
Boeing B-314 (Pan Am Clipper)
Martin PBM Mariner (two engines and just meeting the spec)
Short Sunderland
Blohm u. Voss Ha 139 (barely makes it and does not carry the specified load)

So, such an aircraft is possible. It would be very costly to build and given the German aircraft industry would require an inordinate amount of production capacity to build badly hurting other programs.