What if Germany had better long range sea-air recon?

[stg 44]

http://en.wikipedia.org/wiki/Blohm_%26_Voss_BV_138
http://en.wikipedia.org/wiki/Dornier_Do_26
In my heavy bomber thread phylo_roadking raised a very interesting idea: why didn't Germany go for smaller, long range, fuel efficient sea planes to recon for German subs and convoy raiders?
The use would be obvious, as would the value of having a machine that didn't require special runways or large amounts of fuel, but was still long range and large enough to carry radar gear, torpedoes and bombs.
The engines for the two above craft were not used on any other planes, so no conflict there, and they used the same engines, so even better!

Both were available relatively early 1937 and 1939 respectively, meaning that pre-war units could be set up and trained in spotting for subs and other convoy raiders, as well as bombing units. They have range as good as, or better than a four engine heavy bomber and much better fuel economy. The only draw back is that they didn't have high speed or very large capacity for bombs, but their range IMHO makes up for it.

So what effect would 300 of the BV-138's and 100 of the Do-26's have on the Battle of the Atlantic?

[Dave Bender]

So what effect would 300 of the BV 138's and 100 of the Do 26's have on the Battle of the Atlantic?

What historical assets will the German navy forego in order to pay for these aircraft, aviation fuel, additional catapult ships etc.?

BTW, why produce two different models of long range seaplane? Why not pick the most cost effective aircraft and mass produce it as Göring did with the Me 109 fighter and Ju 88 light bomber?

[stg 44]

So what effect would 300 of the BV 138's and 100 of the Do 26's have on the Battle of the Atlantic?

What historical assets will the German navy forego in order to pay for these aircraft, aviation fuel, additional catapult ships etc.?

BTW, why produce two different models of long range seaplane? Why not pick the most cost effective aircraft and mass produce it as Göring did with the Me 109 fighter and Ju-88 light bomber?

Their wide variety of other boats. This would be a standardization of units that would ultimately require the Luftwaffe to kick in some resources as well, as they had their own recon units for naval use, which was really just duplicating efforts. So in a sense its a rationalization of efforts that requires little more than common sense and cooperation.

These two aircraft were really the best of the bunch. Two versions are mentioned, because it makes sense to build the one early on when it becomes available, while when the second better one hits production time, it makes sense to start to phase out the older one, but still utilize what resources are available so long as they are functional.

[Tim Smith]

What historical assets will the German navy forego in order to pay for these aircraft, aviation fuel, additional catapult ships etc.?

Well, Germany built 700+ landing craft for the invasion of Britain that were never used in their intended role - how about foregoing 300 of those?

http://www.german-navy.de/kriegsmarine/ ... index.html

And why would Germany need catapult ships to operate flying boats? Catapult ships are for seaplanes, not flying boats.

(I know stg 44 describes the Do 26 and BV 138 as seaplanes in the OP, but he's wrong - they are both flying boats.)

[Dave Bender]

Standard German operational doctrine. Lufthansa and the KM used catapult ships to make take off easier when seaplanes were fully loaded with fuel. The Luftwaffe experimented with rocket assisted take off of land based bombers for the same reason.

Landing craft were funded by the Heer. The KM won't be tapping into the Heer budget anymore then they will be tapping into the Luftwaffe budget. If the German Navy desires a serious aviation program they must pay for it themselves.

[Tim Smith]

Standard German operational doctrine. Lufthansa and the KM used catapult ships to make take off easier when seaplanes were fully loaded with fuel. The Luftwaffe experimented with rocket assisted take off of land based bombers for the same reason.

Really? Do you have any photos of a Do 26 or Bv 138 being launched by catapult?

[Carl Schwamberger]

......

So what effect would 300 of the BV-138's and 100 of the Do-26's have on the Battle of the Atlantic?

For that take a close look at the number of Brit ships sunk by aircraft, and aircraft distributed mines, match to how many aircraft and aircraft sorties that took. Then extrapolate to the new number hypothetically available, then adjust to the capabilities of the aircraft. Its something I've been really curious about, but have not had the time for yet another historical analysis & search for data to base it on.

I suspect from my scrap paper guesses the the theoretical number of Brit cargo ships sunk would shock many people & generate a lot of argument. & the results were this tied to a general German air campaign vs the ports, distributing mines, ect.. rather than the historical BoB would bring on a lot of shouting here. But, thats just a suspicion.

[stg 44]

......

So what effect would 300 of the BV-138's and 100 of the Do-26's have on the Battle of the Atlantic?

For that take a close look at the number of Brit ships sunk by aircraft, and aircraft distributed mines, match to how many aircraft and aircraft sorties that took. Then extrapolate to the new number hypothetically available, then adjust to the capabilities of the aircraft. Its something I've been really curious about, but have not had the time for yet another historical analysis & search for data to base it on.

I suspect from my scrap paper guesses the the theoretical number of Brit cargo ships sunk would shock many people & generate a lot of argument. & the results were this tied to a general German air campaign vs the ports, distributing mines, ect.. rather than the historical BoB would bring on a lot of shouting here. But, thats just a suspicion.

I was thinking more as spotters for Uboats, as something like only 34% of convoys were ever spotted historically and only 17% engaged. A lot of this has to do with poor prewar training for recon crews, who were not prepared in navigation over open waters with no land masses around to help guide Uboats, thanks to Luftwaffe domain over these units. Much has to change with Goerings's attitude methinks....

But on the issue of torpedoes and mines, the KM weren't focused on it, only recon, while the Luftwaffe. supposedly having domain over such units, never actually trained in it pre-war, meaning ad hoc units performed poorly and ensured Magnetic mines fell into British hands early when mining units dropped some units on land by accident.

[Dunash]

Really? Do you have any photos of a Do 26 or Bv 138 being launched by catapult?

Well here's a video:

http://www.criticalpast.com/video/65675 ... rman-ships

[phylo_roadking]

I suspect from my scrap paper guesses the the theoretical number of Brit cargo ships sunk would shock many people & generate a lot of argument. & the results were this tied to a general German air campaign vs the ports, distributing mines, ect.. rather than the historical BoB would bring on a lot of shouting here. But, thats just a suspicion.

Two things worth noting on the historical situation -

Yes, Winston called the Condor "the scourge of the Atlantic"....but actually, it didn't sink that many ships in number Those they sank turned out to be of relatively large tonnage, so the overall tonnage attributable to the Fw200 was very large!

Second - there was nothing remarkable about that the Condor did; moreso when you remember that in its early days as a recce bomber it had a very poor bombsight that had to be zeroed in at the start of every mission by dropping dummy ordnance! Instead, KG40 employed an attack profile that involved straddling a ship with three bombs...at least one of which was guaranteed to be close enough to force in the cast iron plates of a period single skinned merchant vessel! There wasn't actually anything "precision" about it! A near miss....virutally guaranteed by the attack profile...would spring plates.

[Dave Bender]

Bv138s were routinely launched by catapult ship. So were most Dornier seaplanes such as the Do-J (Wal) and Do-18.

The Do-24 was constructed to a Dutch specification. Consequently it may not have been compatible with German catapult ships.

The Do-26 was designed to a Lufthansa specification that included compatibility with catapult ships. Historically only 6 were built so I don't know if any were assigned to seaplane tenders. But that was the intention.

[Carl Schwamberger]

......

So what effect would 300 of the BV-138's and 100 of the Do-26's have on the Battle of the Atlantic?

For that take a close look at the number of Brit ships sunk by aircraft, and aircraft distributed mines, match to how many aircraft and aircraft sorties that took. Then extrapolate to the new number hypothetically available, then adjust to the capabilities of the aircraft. Its something I've been really curious about, but have not had the time for yet another historical analysis & search for data to base it on.

I suspect from my scrap paper guesses the the theoretical number of Brit cargo ships sunk would shock many people & generate a lot of argument. & the results were this tied to a general German air campaign vs the ports, distributing mines, ect.. rather than the historical BoB would bring on a lot of shouting here. But, thats just a suspicion.

I was thinking more as spotters for Uboats, as something like only 34% of convoys were ever spotted historically and only 17% engaged. A lot of this has to do with poor prewar training for recon crews, who were not prepared in navigation over open waters with no land masses around to help guide Uboats, thanks to Luftwaffe domain over these units. Much has to change with Goerings's attitude methinks....

But on the issue of torpedoes and mines, the KM weren't focused on it, only recon, while the Luftwaffe. supposedly having domain over such units, never actually trained in it pre-war, meaning ad hoc units performed poorly and ensured Magnetic mines fell into British hands early when mining units dropped some units on land by accident.

Hmm... yes I see your point. Just today I was reviewing Hughes & Costello's 'The Battle of the Atlantic' & ran across a complaint of Doneitz about the lack of good recon to supplement the radio signal intel he had.

[Dave Bender]

Payload and max speed.
Payload = Max weight less empty weight.

4,150 kg. 162 mph. Do-18. 2 x Jumo 205C diesel engines.
4,480 kg. 171 mph. Bv-138C. 3 x Jumo 205C diesel engines.
4,900 kg. 211 mph. Do-24. 3 x Bramo 323R engines.
6,280 kg. 258 mph. He-111 H3. 2 x Jumo 211D2 engines.
7,600 kg. 347 mph. Do-217M. 2 x DB603 engines. 2,500 kg bomb bay.
9,300 kg. 201 mph. Do-26A. 4 x Jumo205D diesel engines.
9,749 kg. 224 mph. Fw-200 C3. 4 x Bramo 323 engines.

Payload is the most important factor for a long range patrol bomber. That tells you how much fuel and weapons the aircraft can carry. Max speed is a secondary but still important factor as it improves survivability if you encounter enemy fighter aircraft.

The Bv-138 would not be my first choice. If you want a seaplane then go with the Do-26. Payload is double what the Bv-138 can carry, it's 30 mph faster and the Do-26 is compatible with standard German catapult ships.

IMO land based aircraft offer superior overall performance.

[gurn]

Perhaps a technology/material exchange could be arranged with the Japanese?
Something that has the Germans recieving a Kawanishi H6K?
A range of just over 4,000 miles would be handy.
As previously mentioned(somewhere on this forum by somebody) if the gas engines could be replace by similiar sized and powered diesels it would allow either the plane or the sub to act as a refueler.

[phylo_roadking]

if the gas engines could be replace by similiar sized and powered diesels it would allow either the plane or the sub to act as a refueler.

Hmm, a rendezvous....all arranged by radio...

Can you imagine the mess of the submarine force that would have allowed the RN/RAF to make, courtesy of Bletchley Park??? Not just a case of knowing where they were - but also when they'd be on the surface stationary???