I think it's safe to assume that had the Germans started investing into a serious strategic bombing capability, the Soviets would have responded by improving their own air defense. With the Soviets grinding down the Luftwaffe, I'm sure the Western Allies would be happy to help with material support.
Not sure why you think they weren't already pouring resources into that and failing badly:
Also, the Allies had zero interest in supporting the Soviets prior to the 1941 invasion and then they did supply them with AAA, radar, and aircraft. Philip O'Brien who wrote "How the War Was Won" specifically points out how Stalin was begging for aircraft and AAA since the moment L-L was granted. The Soviets got as much as good could transported, everyone understood the importance of airpower.
The problem for the Soviets is they had experienced insane damage by the end of 1941 and had way too much territory to defend. Remember they lost their entire pre-war army and air force in the initial invasion and were in many ways a glorified militia by the end of the year. Equipment and manpower losses were beyond insane, it is a miracle they survived IOTL. There wasn't more they really could do compared to OTL.
For comparison, the UK Bomber Command was capable of launching main force raids with around a thousand aircraft. In order to be able to do this, during the war the UK produced around 16000 four engined bombers (Stirling, Halifax, Lancaster), to cover for losses, replacement with newer models, and some amount siphoned off to other roles like training, etc.
When? In 1942 they had to mobilize everything they had, including their training force to be able to launch a single 1000 bomber raid. Later on they could do that more regularly, but only at immense cost and having only 50 divisions. In fact by 1944 they were disbanding divisions and even companies to keep up strength due to lack of manpower.
Also remember the British were trying to burn down entire cities, the Germans are just trying to hit factories. The US was able to do so with a few hundred bombers and able to badly damage multiple sites:
In Regensburg, all six main workshops of the Messerschmitt factory were destroyed or severely damaged, as were many supporting structures including the final assembly shop. In Schweinfurt, the destruction was less severe but still extensive. The two largest factories,
Kugelfischer & Company and
Vereinigte Kugellager Fabrik I, suffered 80 direct hits.
[28] 35,000 m
2 (380,000 square feet) of buildings in the five factories were destroyed, and more than 100,000 m
2 (1,000,000 square feet) suffered fire damage.
[29] All the factories except
Kugelfischer had extensive fire damage to machinery when incendiaries ignited the machine oil used in the manufacturing process.
Albert Speer reported an immediate 34 percent loss of production.
So if we assume the same 16:1 ratio for the Germans, throughout the war they'd then need to produce about 3200-4800 strategic bombers in order to sustain a main force of 200-300. With 6 engines per aircraft (per the original post in the thread), and assuming each engine on an aircraft needs about 1.5 engines for replacements, spare parts etc.(?), we end up with requiring on the order of 30000-45000 engines.
Why would we do that? The British and Germans are going after very different things. The USAAF 8th AF in 1943 is comparable to where the Germans would be at ITTL in 1941, but with a much weaker opponent.
History is full of diesel engines working perfectly fine with throttling up and down, and running at high power for a long time, so I'm not sure this is something inherent to diesels, but rather some deficiency of the Jumo aero diesels that could have been fixed with more development.
Remind me of an example from history showing that with aviation diesel?
Ok, it is about 1850km from Smolensk to Tankograd or well over twice the distance from Eastern England to Berlin.
It also about 1200km from the German border to Smolensk.
So for this plan to work the Germans have to............
1. Design a bomber (or start work) in 1939-40 on a bomber with a 3700km range.
2. Arrange for production of that bomber.
3. Come up with an army that can capture and hold Smolensk in 1942-43 (plan on it in 1940)
4. Arrange for the logistics to be in place in 1942-43. Like the railroads and rail cars needed to supply such a force, including aircrew and mechanics.
Local engine repair/overhaul (or at least such a shop in Poland or Lithuania).
How many tons of fuel per raid?
How many support personnel for every plane, 12-18,000 men for this bomber force?
5. Come up with a navigation system that will work at 2000 km. (beam systems used over England will not work)
Good points, but I'll respond in detail.
Why start work in 1939 when they were starting work on the Ju89 in 1936? By 1941 the bomber would exist and be in production. Roughly the same development cycle of the B17. Having a bomber with that range is doable within the OP with 6x 1000hp Jumo 207s. They give fuel economy about 1/3rd better than equivalent petrol engines.
Also from Kharkov it is about 3422km range. They'd only be able to take at most 2000kg of bombs, but even with 150 bombers that's 300 metric tons. The Messerschmitt factory in that damaging raid in 1943 cited above only took about 270 tons of bombs.
Quoted from above again:
In Regensburg, all six main workshops of the Messerschmitt factory were destroyed or severely damaged, as were many supporting structures including the final assembly shop.
Keep in mind the Germans were already making 4 engine aircraft and without needing to make the He177 or Fw200 they have production capacity. Again, remember they build 1200+ He177s IOTL and then Fw200s and several other large aircraft, including the Bv222.
IOTL they took Smolensk, Bryansk, and Kharkov in 1941 and held them well into 1943. All of these cities had large airfields. There is a Luftwaffe base pdf online you can find pretty easily that lists all 3 as having Class I (top level) airfields capable of handling all aircraft. The logistics in place in 1942 is really not that hard considering they were already operational air bases.
As to the manpower requirements again the Germans fielded 1200 He177s alone and the Luftwaffe was a force of over 1 million men that constantly shed personnel to act as ground forces from 1942 on, so they had plenty of manpower to handle this given the low numbers you cite.
I will grant you that navigation would be somewhat of an issue and that was in fact raised by the RAND corporation, but overall they cited German successes in bombing efforts of strategic and operational targets as well as Soviet failures to defend against them:
A chronicle of the failure of German air force efforts to mount a strategic bombing offensive against industrial targets in the USSR.
It's a quick read and well worth the time.
Of course, hitting the Urals might not even be necessary, given that Gorky and the Upper Volga production region was much closer and a heavy payload could be carried to hit those targets (4-5000kg of bombs at least per bomber given the HP and fuel economy available from 6x Jumo 207s). Bombing of those targets was started in November 1941:
Likely for most of 1941 the heavy bombers would be conducting interdiction attacks on Soviet rail centers until the war is clearly going long, then they would likely be used for industrial attacks, like the 1942 raids on Gorky while they figured out the navigation problems for attacks against the Urals. Of course hitting the concentrated major rail centers that linked the Urals to the west of the country could also bear fruit, that served the Allies very well in 1944-45 when destroying the German economy. It might even have an impact on Case Blau if they can really disrupt Soviet rail movement of reserves, including during run up to Stalingrad. Destroying their rail yards in August could create enough delays in moving in reserves to defend the city in time.
6. Figure out how to stop the Soviets from intercepting the bombers on the way in or out.
at 400kph it is going to take over 4 1/2 hours in and 4 1/2 hours out the Germans are not going to be able to do much in the way of dog legs like the 8th Air Force did and there is no large body of water like the North Sea to offer any sort of refuge. Granted there is an awful lot of Russia without AA guns but that is not quite the same thing. Chinese actually did fairly well with telephones spotting Japanese raids (20-30 minute warning) because of slow bombers, large area/distances and limited targets. Russia is sort of the same. Soviets have over 6 hours to arrange for intercept on the way out?
The Soviets basically did a piss-poor job of it. As noted in the Rand report the 700 sorties against Gorky in June of 1943 suffered lower than 1% loss rate. Even in 1944 strikes against major rail yards suffered negligible losses. The Soviets lacked a national integrated air defense system, it was all regionally based and most of their efforts were focused on major political areas like Moscow and Leningrad. Other than those 2 cities the Soviets had minor defenses covering everything else. Also, even in 1944 their fighters lacked the altitude to reach the few He177s raids that were launched:
On the Eastern Front, the most notable action by the He 177 was a mass raid of some 87 aircraft against railway targets in the
Velikiye Luki area, about 450 km (280 mi) west of
Moscow on 19 July 1944. The participating
Staffeln flew in three large attack wedges of about thirty aircraft, each loaded with four 250 kg (551 lb) or two 500 kg (1,102 lb) bombs.
[70] During this action, carried out in daylight at altitudes in excess of 6,000 m (19,690 ft), losses were relatively light. The Soviet Air Force, equipped mainly for low-level interception and ground-attack roles, could do little to hinder the high-flying bombers.
[71][72]
Most of Russia is empty space, so most of the flight path won't be around any airbases or AAA. Really only over the target, which is too late to engage for the defenders by then. Also besides having altitude problems, the Soviets lacked much in the way of radar and their fighters had weak armament to confront even .50 caliber equipped heavy bombers. The Germans had a horrible time engaging B17s in 1942 due to light armament. Even 20mm guns were not really enough to tackle the heavies in bomber boxes. Not saying the Ju89 even developed by 1941 would have that level of heavy firepower, but it would have enough to tackle the weak armament of Soviet fighters assuming the Soviets could even reach them in time.
The MiG3 was the best fighter the PVO (Soviet air defense) had that had an engine capable of reaching the necessary bomber altitudes.
1x 13mm MG is not going to do more than scratch the paint of a heavy bomber. As I said the Germans had trouble with 20mm cannons vs. 4 engine bombers.
Also interesting:
Pilot Alexander E. Shvarev recalled: "The Mig was perfect at altitudes of 4,000 m and above. But at lower altitudes it was, as they say, 'a cow'. That was the first weakness. The second was its armament: weapons failure dogged this aircraft. The third weakness was its
gunsights, which were inaccurate: that's why we closed in as much as we could and fired point blank".
[18]
Having to get that close to a heavy bomber with its defensive guns was suicide.
Comparison, if we use the defensive armament of the He177 as a model:
- Guns: ** One 7.92 mm (0.312 in) MG 81 machine gun in nose.
- One 20 mm (0.8 in) MG 151 cannon in forward belly gondola, and one in tail.
- Two 13 mm (0.5 in) MG 131 machine gun in FDL 131Z remotely operated forward dorsal turret, and one in rear belly gondola, one in manned HDL 131/1 aft dorsal turret