German heavy bombers

[Thumpalumpacus]

What if Wever had not been killed in the crash? The primary Luftwaffe proponent of heavy bombing in the Douhetian mold, how might his continued command have changed Luftwaffe doctrine, strategy, tactics, and equipment?

My own thoughts are that he would have of course pushed for, and perhaps succeeded in, getting more LW heavies in earlier. I think that the German industrial base couldn't really support a large fleet of big bombers, neither in manufacturing nor in support -- say, fueling thirsty planes, or how many engines can you really build to make this happen?

But if they had some of these heavies around (of whatever design), how might that have affected the Battle of Britain or the invasion of Russia, in your opinion? How would it affect "Blitzkrieg" by taking resources away from close-support aircraft or doctrine? Battle of the Atlantic?

I am curious about the opinions here, of such an informed crowd. Also. for the sake of this hypothetical, let us set aside the whole dive-bomber thing, which I think we all agree is mostly pretty stupid beyond single-engined craft due to size issues

 

[Shortround6]

My own thoughts are that he would have of course pushed for, and perhaps succeeded in, getting more LW heavies in earlier. I think that the German industrial base couldn't really support a large fleet of big bombers, neither in manufacturing nor in support.

Without an increase in manufacturing I don't see a major change in the results. Twin engine plane carrying two tons or 4 engine plane carrying 4 tons? The 4 engine plane may do a bit better. However I doubt that you are going to get anywhere near an equal number of bombers using 4 engine planes so the "lift/bomb load" per 100 engines built may favor the 4 engine machine but not by a large amount.

But if they had some of these heavies around (of whatever design), how might that have affected the Battle of Britain or the invasion of Russia, in your opinion? How would it affect "Blitzkrieg" by taking resources away from close-support aircraft or doctrine? Battle of the Atlantic?

My own opinion is that it makes very little difference to the BoB. If the Luftwaffe could hit Belfast Ireland repeatedly then having longer range bombers doesn't give much advantage there. Perhaps having 4 engine bombers that could carry 2 1/2 times what 2 engine bombers could carry at short range may be an advantage, or carry larger bombs. You would need fewer aircrew although ground crew would not be big difference.
Russia is a bit different although the "Ural" bomber was a pipe dream. The radio beam navigation system the Germans used over Britain would not work over most of Russia or at least at the ranges where the 4 engine bombers are going to show an advantage. Using traditional navigation the Germans may not have much better success than the British had early in the war. Some areas of Russia had vast expanses of nothing (fields) between major cities, hundreds of kilometers.

Even if the Germans don't use the big bombers for close support even tactical bombing (supply/rear areas and not actual battle support) means you have fewer planes to cover a large number of targets (bridges, railroad yards, supply dumps, etc), If you have 1/2 the number of planes, even if they carry more bombs can you divide them up as effectively.

You might get a more effective plane than the Fw 200. You may get a some more of them. If you try attacking convoys with 4-12 planes at a time you may provoke a stronger British response. Earlier deployment of escort carriers or conversions of a few fast commercial hulls as emergency carriers?
Does more planes result in better search/tracking a few hundred km west of Ireland? Time between spotting a convoy and arrival of strike force is how many hours?

 

[tomo pauk]

Perhaps having 4 engine bombers that could carry 2 1/2 times what 2 engine bombers could carry at short range may be an advantage, or carry larger bombs. You would need fewer aircrew although ground crew would not be big difference.

Savings in the aircrew per "ton*mile" (ton of bombs times the distance) would've been the most noticeable improvement IMO. People like pilots, navigators, bomb aimers, radiomen - many hundreds of each. Trained pilots were in great demand in the ww2 Luftwaffe.

Against the historical bomber force, swapping the last 50% of the Do 17s with 4-engined bombers might've meant a big increase of payload capability against the twice the number of the Do 17s, since these carried just a meager bombload. Plus, we also have 1900+ of Do 217s, that if replaced with a decent 4-engined design would've probably meant 1200-1400 heavy bombers made? Similar math can be employed to the Ju 88, or the He 111.
Another advantage of the bigger bombers is that these easily justify the heavier defensive firepower, that is also easier to install on the aircraft.

 

[Shortround6]

Savings in the aircrew per "ton*mile" (ton of bombs times the distance) would've been the most noticeable improvement IMO. People like pilots, navigators, bomb aimers, radiomen - many hundreds of each. Trained pilots were in great demand in the ww2 Luftwaffe.

Against the historical bomber force, swapping the last 50% of the Do 17s with 4-engined bombers might've meant a big increase of payload capability against the twice the number of the Do 17s, since these carried just a meager bombload. Plus, we also have 1900+ of Do 217s, that if replaced with a decent 4-engined design would've probably meant 1200-1400 heavy bombers made? Similar math can be employed to the Ju 88, or the He 111.
Another advantage of the bigger bombers is that these easily justify the heavier defensive firepower, that is also easier to install on the aircraft.

All good points but some times the degree of change might not be great due to details and timing.

Four engine bombers using Bramo 323P engines?
1000hp for take-off until they get water injection.
I have no clue were the Germans go with this. A 700-1000sq ft wing for speed or a larger wing (1100-1200sq ft) for lift, bomb load range?


An early 111H had 1200hp engines.
He 111s compete with JU-88s for engines, at least in the first few years.

Germans in 1939-40 have crap for guns. I have no idea why they didn't stick belt feed MG 17s in defensive positions or try to use twin MG 15s.
Germans made the mistake of trying go directly from the manually aimed MG 15 7.9mm machine gun to the remote control turret/barbette skipping the manned turret. There manned turrets look like after thoughts or fall back positions after the gee-whiz remote control stuff failed, but that is somewhat different from the 2 engine vs 4 engine debate.

Germans had an engine problem. They didn't have a good 1300-1600hp engine for much of the war. Or it arrived late.
US had 1600-1700hp bomber engines in 1941. Or turbo 1200hp engines which sort of acted like 1600-1700hp engines at altitude.
British had the XX Merlin or the Hercules in 1941/42.
Germans get the BMW 801 and that is the headliner until they get the Jumo 213.

 

[tomo pauk]

Four engine bombers using Bramo 323P engines?
1000hp for take-off until they get water injection.
I have no clue were the Germans go with this. A 700-1000sq ft wing for speed or a larger wing (1100-1200sq ft) for lift, bomb load range?

That is about 80% of power that the engines on the Halifax I had. Granted, the Halifax I was with it's shortcomings, but even if the bombload vs. range is half of it (= half of 13000 lbs at 1000 miles, or half of ~8000 lbs at ~1800 miles), this means that one not-so-great 4-engined bomber carries as much as 3 Do 17Zs.
Upgrading the engines to the Jumo 211s should not be such a bad deal after the BoB.

An early 111H had 1200hp engines.
He 111s compete with JU-88s for engines, at least in the first few years.

A 4-engined bomber competes with both of them for engines.

Germans in 1939-40 have crap for guns. I have no idea why they didn't stick belt feed MG 17s in defensive positions or try to use twin MG 15s.
Germans made the mistake of trying go directly from the manually aimed MG 15 7.9mm machine gun to the remote control turret/barbette skipping the manned turret. There manned turrets look like after thoughts or fall back positions after the gee-whiz remote control stuff failed, but that is somewhat different from the 2 engine vs 4 engine debate.

4-engined bombers have the much roomier fuselages, so there is an incentive to make the more substantial defensive positions? The turrets like what the British had on Wellington or the Whitley would've looked very good on the German 4-mots.

Germans had an engine problem. They didn't have a good 1300-1600hp engine for much of the war. Or it arrived late.
US had 1600-1700hp bomber engines in 1941. Or turbo 1200hp engines which sort of acted like 1600-1700hp engines at altitude.
British had the XX Merlin or the Hercules in 1941/42.
Germans get the BMW 801 and that is the headliner until they get the Jumo 213.

4-engined bombers have an appeal that they don't require the latest and bestest engines, and that re-engining the bomber is pretty straightforward job. A bomber with 9 cyl radial should accept the V12 engine without much of an issue, while the one made with the V12 might accept a 14 cyl radial, even if it is a heavier engine than usual.
The German next-gen bombers were in the world of hurt when the gee-whiz 24 cyl engine didn't worked, or even when the DB 603 was with it's host of problems. Or, see the Manchester - it needed a switch from a wow great engine to the everyday engines - and 4 of them on a bigger wing - to became a fine bomber in shape of Lancaster.

The Jumo 211F, J and N from mid war certainly fit in the 'good 1300-1600 HP engine' category, so do the DB 601E and 605A (talking about the de-rated engine). German engines used less fuel per HP than the British - gets more important when greater range is required.
BMW 801 also worked, and far better than the alternatives. Bombers don't need the short term jump in power like the fighters.

 

[Shortround6]

A lot depends on what the Germans actually want it to do and when.

The Avro Manchester went into service as a 265mph top speed bomber. Issued to squadrons at the end of 1940, first combat (over Brest, not exactly long range), in late Feb 1941.
The larger Stirling, when it got 1500hp Hercules XI engines could hit 282mph but cruised at closer to 200mph. First combat in Jan 1941, 3 planes. Two Stirling factories were severally damaged by German twin engine bombers, the already mentioned Belfast raid was in March of 1941.

The French were working on several 4 engine bombers in the spring of 1940 but they went for speed, over 300mph (and yes nobody actually flew bombers at near top speed, just an indicator as to what direction they were taking) even with their low powered engines, but this meant smaller wings and lower bomb loads than the British heavies.

This was sitting on the runway with engines running when the word came that all flights were canceled, so all we have are estimates. 947 sq ft wing, four 1140hp engines.
Estimated top speed of 335mph. loaded weight 39,835lbs. It could hold a pair of 496lbs in each wing root and had a 19ft long bomb bay (future torpedo bomber?)
one 7.5mm mg in the nose, one 20mm in a power mount on top and a pair of 7.5mm mgs out the lower rear step. Maybe somebody else had range numbers?

Just pointing out that there were other paths than what Britian and the US used/planed.
But for the Germans replacing 500 or more Do-17s is going to mean an older, less sophisticated plane than this (production started in early 1939?) while a having several hundred bombers in the summer of 1941 could mean something close to this or............the old design with better engines.

 

[don4331]

Replacing almost 1,200 He.177s with a proper 4 engine bomber has to have some benefit

I understand, there's some issues with having engines available in volume earlier, but need = creation of factories to build them (and they aren't the high demand/troubled DB 601/606, but possibly Jumo 211 or Bramo 323s). So, a Bomber A started in '36 under Wever might​

​

If you're short on power, why not 6 engines ala Bv222/238?

​

And maybe Germans go with an equivalent to the Zveno project - to provide fighter escort and/or dive bomb accuracy if the heavy bomber needs it.

 

[Shortround6]

A lot really depends on timing.

Do 19 that first flew in 1936 with Bramo 322 715hp engines and 1724 sq ft of wing area. About 21% bigger than Boeing 299 (XB-17). in a few years you can make the wing smaller as the engines get more powerful. The B-17 with it's smaller wing started with 750hp P & W Hornet engines about one year earlier (1935). B-17 didn't get the turbos until early 1938.
Boeing 299 was also about 20% lighter than the Do 19. but use caution, bomber weights are all over the place, even on some these old ones there were thousands of pounds difference between "normal" load and "overload".
Sometimes timing and luck come into play. Dornier could have fixed the nose, they could have fixed the tail and they could certainly have changed the engines. Changing the wing by 15-25% gets a lot harder.

Do 17M of 1938.

engines are Bramo 323s but they are 900hp for take off and 1000hp at 10,200ft. The "belly" gun is fired down out of hatch in floor and not backwards like the later Do 17Z.
3 man crew.

Nothing says the Germans could not have built several different 4 engine bombers. They are not locked into one but each one should be appropriate to it's time. A Battle for France/BoB bomber should use engines and guns in wide spread use in the summer of 1940. Upgrade for 1941 or introduce new airframe?

 

[Shortround6]

We have skipped right past the Fw 200.
Given enough time (and big enough orders) there doesn't seem to be any reason that the Fw 200 could not have been more extensively modified to become a late 30s and/or 1940-41-42 bomber.
The B-17E was certainly much modified from the B-17B let alone the Boeing 299.
Boeing used the wings and tail of the early B-17s on the 307 Stratoliner prototype and then used the Modified 307 vertical fin and rudder on the B-17E.
The wing area was close, 1420 sq/ft to 1290sq/ft for the Fw 200 and the wing spans were close Fw 200 had 4 more ft. Weights were not that different, at least on the early B-17s (before the F).
We all know that the Fw 200 needed some beefing up and it might have gained a bit of speed (not a lot) from a smaller fuselage. But they built 276 (?) of them so there wasn't much retooling as they were waiting for Vundar bombers that rarely showed up and never on time. Slap a Band-aid or sticking plaster on the FW 200 and make do.
But you have less power for take-off (until water injection) and power falls off over 10,000-13,000ft depending on which Bramo engine.

Fit larger bomb bay or fit wider/shallower gondola (or fit vertical racks inside?) If they had ordered 300-500 all at once perhaps significant changes could have been made.
Doesn't solve the crappy armament though. Although not any worse than the B-17C before upgrade.

 

[Thumpalumpacus]

We have skipped right past the Fw 200.
Given enough time (and big enough orders) there doesn't seem to be any reason that the Fw 200 could not have been more extensively modified to become a late 30s and/or 1940-41-42 bomber.
The B-17E was certainly much modified from the B-17B let alone the Boeing 299.
Boeing used the wings and tail of the early B-17s on the 307 Stratoliner prototype and then used the Modified 307 vertical fin and rudder on the B-17E.
The wing area was close, 1420 sq/ft to 1290sq/ft for the Fw 200 and the wing spans were close Fw 200 had 4 more ft. Weights were not that different, at least on the early B-17s (before the F).
We all know that the Fw 200 needed some beefing up and it might have gained a bit of speed (not a lot) from a smaller fuselage. But they built 276 (?) of them so there wasn't much retooling as they were waiting for Vundar bombers that rarely showed up and never on time. Slap a Band-aid or sticking plaster on the FW 200 and make do.
But you have less power for take-off (until water injection) and power falls off over 10,000-13,000ft depending on which Bramo engine.

Fit larger bomb bay or fit wider/shallower gondola (or fit vertical racks inside?) If they had ordered 300-500 all at once perhaps significant changes could have been made.
Doesn't solve the crappy armament though. Although not any worse than the B-17C before upgrade.

Ready by what timeframe?

 

[Sons of Anzac]

I would suggest that had Wever survived, the best he could have got was limited production of one of the heavy bomber prototypes with enough to fill out 2 or 3 KG, with the remaining KG in the LW being the twin engined types. That would still keep to their tactical reasoning but give a limited capability at long range heavy bombing.

 

[Zmauky]

That's a nice topic and this is what iff section - Not exactly a modeling part but... a couple of months ago I sketched Out Do 117. The story begins with a Monogram model of Dornier in 1/72 which is no longer comparable with ICM or Airfix (and it's not exactly accurate). And so... POD is that after the introduction of Bf 162 in the role of schnellbomber Do 17 has ceased to be fast or have comparable payload so the only solution was... Increase the number of engines. The plane has a "minimum" of modifications - the middle part of the wing (with two engines and an extended bomb bay) the outer part of the wing /cabin is the same and the tail slightly (too) enlarged. The main question... How much bomb load?

 

[OldGeezer]

Anyone interested in questions like this should read Cajus Bekker's "Luftwaffe War Diaries" where Appendix 11 is the 1954 statement "by Field-Marshal Kesselring on the Subject of Luftwaffe Policy and the Question of a German Four-engined Bomber." Copies of that book seem to be not very widespread, so I'll type it out in full.

"Without denying that valid arguments in favour of a German four-engined bomber existed, I feel bound to refer to the views expressed in many contemporary conversations, particularly with Jeschonnek ... Unless one is aware of the actual situation obtaining in the nineteen-thirties, false conclusions will be reached. The situation can be summarised as follows:
"1. The Luftwaffe had to be created out of nothing, for the previous decade was entirely unproductive.
"2. Up till mid-1935 all practical endeavour had to be carried out in secrecy, thus retarding its efficacy.
"3. To convert their designs into concrete results, both air-frame and aero-engine manufacturers needed time.
"4. Both of them had much to learn by experience before they were in a position to delver really serviceable products.
"5. Development and production were handicapped by the prevailing shortage of raw materials and fuel.
"6. Despite all its growing pains the aviation industry was confronted with the need for converting from relatively light to relatively heavy production (i.e. bombers).
"7. Such a process was also essential to a programme of general training, especially at a time when blind-flying, bad-weather flying, etc., were viewed as 'mumbo-jumbo'.
"8. With aircraft planning (e.g. that of the 'Ural bomber') years ahead of the contemporary political situation, the political programme adjusted itself to the available technical wherewithal. This sufficed for a war in Western Europe with its implicit limitations on air strategy.

"The following conclusions emerge. Even if the role of the Luftwaffe had been viewed as a strategic one, and a well thought-out production programme devised to cover it, by 1939 there would still have been no strategic Luftwaffe of any real significance. Even the U.S.A., which, untroubled by war, was in a position to conduct large-scale planning, only began to deploy strategic bombers in 1943.

"For this reason it was too much to expect Germany to possess a strategic air force as early as 1940 or 1941. Even if suitable aircraft had been available - itself hardly within the bounds of possibility - we should certainly not have had them, or trained crews to fly them, in the numbers necessary for a successful and decisive air operation. It is even questionable, to say the least, whether output could have kept pace with losses.

"With the prevailing shortage of raw materials, the production of strategic bombers in any adequate numbers could only have been achieved at the expense of other aircraft types. One of the lessons of the second world war was the number of aircraft and quantity of munitions it takes to dislocate the economy of a nation.

"Such an objective - in the first years of the war, without the additional armaments potential of adjacent states - was for Germany unattainable. First an extension of the productive area had to be obtained.

"Apart from that, many dispassionate critics were firmly convinced that the rapid successes of German arms were only achieved thanks to the direct and indirect deployment of the whole Luftwaffe in support of the ground troops. Only where the Luftwaffe had prepared the way did the Army advance. For this purpose our main requirement was a close-support force which was not, and could not be, basically under Luftwaffe operational control.

"Even if absolute priority had been given to the creation of a strategic air force, with consequent disregard of a close-support force, the following types of aircraft would still have been necessary:
"1. The same numbers of short- and long-range reconnaissance planes (twenty-two per cent);
"2. Probably even more fighters, particularly of the long-range variety (thirty per cent);
"3. Marine aircraft (eight per cent).

"That would have left a maximum capacity of forty per cent for the production of long-range bombers - enough for 400-500 of them.

"So far as I can assess the position regarding raw materials, fuel and productive potential both of aircraft and trained crews, I can only say that a strategic air force would have been created too late, and the Army would have suffered for want of direct and indirect air support.

"How such a strategic Luftwaffe would have affected the course and outcome of the war is impossible to say. The fact remains that Germany's basic error was to open hostilities when she did. Given that, any criticism of the actual role that the Luftwaffe fulfilled can only be theoretical."

 

[yulzari]

In short, a strategic Luftwaffe could only have been achieved at the expense of a tactical Luftwaffe.

Germany had to have a prime tactical Luftwaffe to achieve the fast victory it needed. A strategic Luftwaffe could not deliver such a victory within a useful timescale and probably could not actually be made anyway. Thus they made the correct decision IOTL. What they did miss out on was a long range maritime component which did need large aeroplanes but who would plan in 1936 to have German Atlantic maritime sorties flown from the Bay of Biscay and northern Norway? Certainly they would not countenance any plan to do those sorties from Germany. The existing planned medium bombers could adequately cover the needs of the Baltic and North Sea.

 

[EwenS]

Fit larger bomb bay or fit wider/shallower gondola (or fit vertical racks inside?) If they had ordered 300-500 all at once perhaps significant changes could have been made.
Doesn't solve the crappy armament though. Although not any worse than the B-17C before upgrade.

Much of the interior of the Condor, at least in its anti-shipping versions, was taken up with fuel tanks to increase its range (5 large & 1 smaller tank). Items 55 & 52 respectively in the linked drawing. And there was a further fuel tank occupying the centre part of the gondola. Item 47.

https://conceptbunny.com/wp-content/uploads/2018/01/Focke-Wulf_Fw_200_Condor.gif

Most of the weight of the bomb load was carried on the underwing racks, partially faired into the engine nacelles.

 

[Shortround6]

What they did miss out on was a long range maritime component which did need large aeroplanes but who would plan in 1936 to have German Atlantic maritime sorties flown from the Bay of Biscay and northern Norway? Certainly they would not countenance any plan to do those sorties from Germany. The existing planned medium bombers could adequately cover the needs of the Baltic and North Sea.

They were looking to the future but what they needed in 1936-1939 was as you say.

Much of the interior of the Condor, at least in its anti-shipping versions, was taken up with fuel tanks to increase its range (5 large & 1 smaller tank). Items 55 & 52 respectively in the linked drawing. And there was a further fuel tank occupying the centre part of the gondola. Item 47.

Thank you.

The Fw 200 was a slapdashed quicky conversion of the airliner version. First for a few orders from the Japanese and then a few for the Luftwaffe when they realized they needed more long range maritime aircraft.

I am trying to play devil's advocate for the idea of German 4 heavy bomber. The Do 19 may be a little too early in aerodynamics and structure. The Fw 200 first flew in July 1937 so there was time to modify it, beef up the wings, smaller bomber fuselage and get it into production by 1939 and have it in numbers (10-20 of anything doesn't change the war) in the spring/summer of 1940.
It has been put forward that the Germans could have switched over Do 17Z production as a possibility. But that means the engines as used by the Do 17Z and the guns (defensive) of the Do 17Z (and the other 1940 German bombers).
Perhaps the Germans, given more time (started bomber prototype in 1936-37 parallel with the airliner) could have put more fuel in the wing. Designed a better bomb bay and so on.
Closer to a B-17C without turbos?

The question is what does that really gain the Luftwaffe?
Yes the Do 17 and Ju 88 were short ranged. But the He 111 was not (for the time) Paris was under 200 miles from the German Border and London was bit under 300 miles from Germany if the Germans overflew Belgium and Holland. If the Germans can pull off 400 mile round trips they can bomb Cherbourg< Rennes, Nantes (?) 30 miles from Saint Nazaire and get to within 30-50 miles of much of the French coast north of Bordeaux. They can also even by dog legging around Switzerland cover the south coast from the Italian border to Beziers (east of Sete).

They still have to figure out escort for daylight.

Germans can start a 2nd generation 1-2 years later and fly a 4 engine He 177 at the end of 1939/Jan 1940 and perhaps get into production in 1941 and have several hundred by 1942.
This affects the Russian campaign how?
And how effective is it?
The Remote turrets don't work in 1942.
And designing a bomber in 1939 that requires you to capture 500-700 miles of Russian territory to even get close to some major Russian targets is a huge gamble. Tankograd was about 900 miles from Moscow. Ural Bomber was drug induced.

 

[tomo pauk]

The question is what does that really gain the Luftwaffe?
Yes the Do 17 and Ju 88 were short ranged. But the He 111 was not (for the time) Paris was under 200 miles from the German Border and London was bit under 300 miles from Germany if the Germans overflew Belgium and Holland. If the Germans can pull off 400 mile round trips they can bomb Cherbourg< Rennes, Nantes (?) 30 miles from Saint Nazaire and get to within 30-50 miles of much of the French coast north of Bordeaux. They can also even by dog legging around Switzerland cover the south coast from the Italian border to Beziers (east of Sete).

They still have to figure out escort for daylight.

Two crucial things are mentioned there:
- the need for escorts is still a thing
- before mid 1941, Luftwaffe needs shorter range/radius of their bombers (and escorts) than what the RAF needed (unless RAF can stage their bombers from France)

Germans can start a 2nd generation 1-2 years later and fly a 4 engine He 177 at the end of 1939/Jan 1940 and perhaps get into production in 1941 and have several hundred by 1942.

+1 on that.

This affects the Russian campaign how?
And how effective is it?
The Remote turrets don't work in 1942. And designing a bomber in 1939 that requires you to capture 500-700 miles of Russian territory to even get close to some major Russian targets is a huge gamble. Tankograd was about 900 miles from Moscow. Ural Bomber was drug induced.

Soviets are still getting hacked in 1941 as they did historically. How effective are the big bombers - there is probably no definitive answer on that.
Nice thing about the big bombers is that they have more elbow room for manned turrets.

Tankograd is not a thing until Soviet Union is invaded, plus the time required to relocate factories, train manpower and start making tanks at Urals.
For the German planners in late 1940-early 1941, the Soviet factories needing destruction are the ones in Ukraine, plus what is at Leningrad and Moscow. For 1942, there is still a lot of energy sector facilities that can't be packed up and moved, like the oil extraction and processing facilities, as well as electric network and steam plants.

 

[tomo pauk]

Anyone interested in questions like this should read Cajus Bekker's "Luftwaffe War Diaries" where Appendix 11 is the 1954 statement "by Field-Marshal Kesselring on the Subject of Luftwaffe Policy and the Question of a German Four-engined Bomber." Copies of that book seem to be not very widespread, so I'll type it out in full.

Thank you for the excerpts, I'll comment a bit on them.

Unless one is aware of the actual situation obtaining in the nineteen-thirties, false conclusions will be reached. The situation can be summarised as follows:
"1. The Luftwaffe had to be created out of nothing, for the previous decade was entirely unproductive.
"2. Up till mid-1935 all practical endeavour had to be carried out in secrecy, thus retarding its efficacy.

We are aware of the secret German training grounds in Soviet Union, that meant the German military in the 1920s was kept well informed, and without the need to cater to the geriatric high officers (as it was the case with France), was free to explore and perfect the new stuff. Secrecy meant that Entente was still oblivious of the new stuff being developed, meaning that Germans were actually the ones having both numerical advantage in military hardware come 1938, as well as in the main topic: how to use all these shiny machines.

Efficacy of other countries militaries was in shambles, not what the Germans had.

"3. To convert their designs into concrete results, both air-frame and aero-engine manufacturers needed time.
"4. Both of them had much to learn by experience before they were in a position to delver really serviceable products.
"5. Development and production were handicapped by the prevailing shortage of raw materials and fuel.

Implying that the prevailing shortage of raw materials and fuel, as it happened in ww2, was also present in the 1930s is a huge misinformation attempt by Albert Kesslering.
Doriner made a concrete 2-engined all-metal aircraft, and the one that can float to boot, already in 1922. They made a 12-engined aircraft in 1932. Most of the other constructors were dabbling in strutted biplanes until mid-1930s. Dornier also made a 3-engined and two separate 4-engined designs in the late 1930s,
Junkers was producing 3-engined aircraft come 1932. The 1st 4-engined Fw transport, the Fw 200, was an instant success in that role.

German engines were very much serviceable, be these their own designs or the licence models. Junkers even made 2-stage superchargers for their engines in order to 'attack' altitude records. Designers in German companies were rarely reverting on biplane or parasol configurations, unlike what was the case in most of the countries.

tl;dr - stating that German designers and engineers were making only the baby steps during the interwar period, and thus were incapable of making good and reliable hardware is, again, attempt on misinformation.

"6. Despite all its growing pains the aviation industry was confronted with the need for converting from relatively light to relatively heavy production (i.e. bombers).
"7. Such a process was also essential to a programme of general training, especially at a time when blind-flying, bad-weather flying, etc., were viewed as 'mumbo-jumbo'.

As above - German companies had no problems in making useful multi-engined aircraft.
Training 500 pilots in blind- and bad-weaher flying is far easier than training 1000 of them - a simple math seems to be eluding the Smiling Albert.

"8. With aircraft planning (e.g. that of the 'Ural bomber') years ahead of the contemporary political situation, the political programme adjusted itself to the available technical wherewithal. This sufficed for a war in Western Europe with its implicit limitations on air strategy.

Again, he is trying to implicate what happened in the 1940s - need to reach the Urals - had any bearing with the realities of the 1930s.

"The following conclusions emerge. Even if the role of the Luftwaffe had been viewed as a strategic one, and a well thought-out production programme devised to cover it, by 1939 there would still have been no strategic Luftwaffe of any real significance. Even the U.S.A., which, untroubled by war, was in a position to conduct large-scale planning, only began to deploy strategic bombers in 1943.

"For this reason it was too much to expect Germany to possess a strategic air force as early as 1940 or 1941. Even if suitable aircraft had been available - itself hardly within the bounds of possibility - we should certainly not have had them, or trained crews to fly them, in the numbers necessary for a successful and decisive air operation. It is even questionable, to say the least, whether output could have kept pace with losses.

I'm not sure why should we equate the number of engines with the role of an aircraft. He 111, same as the Wellington or Whitley, were the bombers capable of reaching enemy assets deep, deep in enemy's territory. Talk close to 1000 km away from the own bases. That is what strategic bombers are for, imperfect as the 3 bombers were.

Gun-armed bombers with greater payloads have a smaller requirement to the non-gunner crewmen per payload weight, not greater.

 

[Shortround6]

The Urals are really big place. Unless somebody has some German documents outlining what they meant the "Ural" thing is certainly up in the air.

What was possible vs what was practical are two different things. The US with their goal of strategic bombing built the XB-15 as sort of a proof of concept example.
Flying in 1937 it had a max range of 5000 miles, it also needed 33 hours at 153mph to fly that distance using two (?) crews flying in shifts.
If you wanted to carry bombs things changed.
Range 3400 miles with 2511 pounds of bombs.
By late WW II B-17s had grown to a max weight very close to the old XB-15 and the B-17 wasn't much newer in concept/construction.

The Germans still need to solve the long range navigation problem. The beams don't work at long range.

The big bombers have more room for manned turrets. The Germans just have develop them. The German turrets seem to show up late and poorly.

Now maybe the Fw 200S (super) can carry 6000lbs inside (50% more than an He111 and 3 times what the Do-17Z can carry) and carry them further. But in 1940 how far do you need to carry them and 5-7 7.9mm machine guns are not going to protect the bomber very well.

 

[SaparotRob]

The Urals are really big place. Unless somebody has some German documents outlining what they meant the "Ural" thing is certainly up in the air.

What was possible vs what was practical are two different things. The US with their goal of strategic bombing built the XB-15 as sort of a proof of concept example.
Flying in 1937 it had a max range of 5000 miles, it also needed 33 hours at 153mph to fly that distance using two (?) crews flying in shifts.
If you wanted to carry bombs things changed.
Range 3400 miles with 2511 pounds of bombs.
By late WW II B-17s had grown to a max weight very close to the old XB-15 and the B-17 wasn't much newer in concept/construction.

The Germans still need to solve the long range navigation problem. The beams don't work at long range.

The big bombers have more room for manned turrets. The Germans just have develop them. The German turrets seem to show up late and poorly.

Now maybe the Fw 200S (super) can carry 6000lbs inside (50% more than an He111 and 3 times what the Do-17Z can carry) and carry them further. But in 1940 how far do you need to carry them and 5-7 7.9mm machine guns are not going to protect the bomber very well.

You should consider adding dive bombing capability to the strategic bomber.