The Luftwaffe and "four engined" bombers

It does work, I see them flying all the time in active service. It is not what they wanted, but it does work.

Prove it. Put up the numbers.

 

Really now, I seem to recall due to a lack of a fuel injector at 20,000 feet the engine had a lot of trouble operating in maneuvers. Since the 11ton overload scenario would be done at night, lets try a day light mission.

60 Ju-89s each loaded with six tons of Bombs targeting the Supermarine Itchen and Woolston works. They are escorted by 100 Bf-109s.

The Formation is at 26,000 feet. Now the British radar pick them up about two hours out and order in 28 Spitfires and 47 Hurricanes. Due to its inefficiencies, the C2 facilities direct 60 percent of the planes to the wrong area at first.

Four Spitfires spot the Formation along with six Hurricanes and climb while stating their position and calling for help. At this height the Bf-109s' engines with their fuel injectors have a big advantage in negative g combat and bounce the British Fighters. As more and more British Planes arrive piecemeal, they are bounced while the Ju-89s continue in formation to the Bomb point. Flak claims one or two bombers and a Hurricane making a head on pass manages to shoot another one down.

However, the majority get through and devastate the Factories. This is how Wever envisioned things.

Actually far superior when you factor in basing from France.

 

OK.

The United States Strategic Bombing Survey goes in to some detail on German oil production and consumption. According to them, German production of aviation fuel in 1940 was 643,000 tons, imports were 78,000 tons and 245,000 tons were captured from France and the Low Countries. Total 966,000 tons.

In 1941 production was 889,000 tons, imports were 21,000 tons, for a total of 910,000 tons.

The USSBS also provides a graph showing production and consumption. In August 1940, consumption hit a peak of 100,000 tons, supply was about 90,000 tons. In September consumption fell to about 95,000 tons, supply to about 65,000 tons.

During the period of the BoB and Blitz, consumption was higher than supply in August, September, October and November. In December, January and February supply edged above consumption, in March, April and May consumption again outstripped supply.

I've attached the graph, but you will probably need to enlarge the image to be able to read the details.

Throughout the period of the BoB and Blitz, consumption seems to be above supply, unless you include the huge spike of over 200,000 tons supplied in July, which is when the stocks were captured from France. From a high of about 780,000 tons stockpiled at the end of July 1940, stocks fell just below 600,000 at the end of November, climbed to about 630,000 tons at the end of March, and fell to about 580,000 tons at the end of April. From May onwards, with the increase in fighting elsewhere, consumption soars and stocks plummet, down to about 250,000 tons at the end of November 1941.

If you can't read the labels on the graph, the lower shaded area is consumption, the lower line is supply, the upper line stocks. Each horizontal line is 100,000 tons. The vertical lines are months, starting in Jan 1940.

No, not at all. It had trouble with negative G at any altitude, but high alt made no difference.

It's worth pointing out that Spitfires hold the record for high altitude combat in WW2, with several interceptions of recce aircraft at over 40,000 ft. (although of course they really struggled at such altitudes)

 

Good Chart!
What the graph suggests is that LW had 5-6 month stockpile even at top fuel consumption in 1940, so they were in little danger of exhausting fuel supplies unless all fuel production halted. With reference to bomber range, different sources have different figures, suggesting that other key information is left out like altitude and load being carried. Also its clear that prototype exceeded specs in load at altitude tests that were carried out detailed in this site.

Junkers Aircraft of WWII

Only two prototype built and tested .The aircraft was listed at 4800kg payload but carried upto 10,000 kg in tests. But that was the second prototype with only 750 hp engines. It also needs to be remined that Ju-89 was product of early 1930s design effort with mass production by 1938. The original was just a purpose designed replacement for Ju-52 bomber and was a considerable improvement in that capacity. We always need to remember that Germans were not preparing for offensive war by 1939, but by 1943-44 period and Ju-89 was only stepping stone towards other plane.

But clearly by 1940 an improved model would have been in mass production and as per usual history that would have featured much more powerful engines [40% improvement in out put?]. All other things being equal, that should increase speed, altitude and payload significantly. So unless we have figures on Ju-89 with improved engines this is quite conjecture. In most production runs improved engines increase speed by ~10%. ...so top speed go to 290 mph and top cruise speed to 220mph?

"Antiwank"

Please, how is this calculation made?

 

That's certainly true for the Luftwaffe historically, but not for the suggested 400 sorties a day by 4 engined heavy bombers.

 

online conversion calculators for temperature, length/ distance, area, volume and weight

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LuftArchiv.de - Das Archiv der Deutschen Luftwaffe

For the stats.

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Perhaps under Goering through Jeschonneck and Udet, but in the German system, Staff Officers are empowered to give orders and if Wever keeps his job as Chief of Staff, he can definitely work to expand synthetic oil production.

Goering has too many other responsibilities to watch over Wever's back and Wever has enough backbone to stand up to him and Hitler.

 

Well, the 400 sorties-a-day thing is obviously a big stretch. The Luftwaffe would have needed somewhere in the area of 700 to 900 bombers to allow for that operating tempo. Also, if we go with historical figures the per day sorte loss rate to operational and combat losses would be 4 to 8% depending on opposition or 16 to 32 bombers per day.
This would mean that the Germans would have to come up with that many new bombers every day to replace losses. Got news on that: I ain't happening! There is absolutely no way the German aircraft industry could have produced 16, let alone 30+ heavy bombers per day. Junker's output of the Ju 290 was about 2 per month. Henkel managed about one or two He 177 per day at their best rate. The most prodigious producer of heavy bombers was without question the Ford Willow Run plant in Illinois. It produced 24 B 24 per day. But, it also dwarfed any aircraft production plant in Germany during the war. It was also a highly orgainzed and, for the time, automated assembly line unlike the mostly piecework German aircraft industry.
So, if we go with 2 replacement aircraft per day and a loss rate of just 4% the Germans might sustain a 50 bomber force over an extended period. More likely, they would do what they historically did. Build up a reasonable force and then use it to exhaustion over a short offensive then take a several month break from intensive operations to just making the occasional small raid before resuming another offensive.

 

Combat records from 20,000 feet up during the battle of Britain show the Spitfire outclassed at that height due to its carburetor engines not functioning properly at that altitude. Granted it was rare that combat took place that high as the German Medium Bombers flew lower to increase the accuracy of their bomb drops.

Though the problem with the carburetor engines was fixed after the battle was over, the point still stands that properly escorted strategic bombers would devastate Britain's ability to make war, so long as they are aiming at the right targets.

That it wasn't the case, Britain can only thank providence that Wever got killed.

 

Wever had plans to increase production, mainly by eliminating many inefficiencies in the production stage (for example the fact that the aircraft factories were using aluminum to make ladders), cut paper work, and concentrate on a few workable designs instead of the Napkinwaffe projects, mad scientists, and ego filled crusaders that killed the Luftwaffe in OTL.

That would give him, if implemented, a production of Ten Ju-89s a day at full tilt. More likely five a day, hey he has to fight screaming matches with the other services, the civilians and Hitler to get resources.

 

The reality is that the German aircraft industry, much like most of the rest of the military industrial complex, was grossly inefficent almost by design. First off, mass production would be resisted by the various worker unions and the workers themselves. Germany had a strong tradition in its Meiser system of skilled craftsmen doing hand work. The next problem is with the Luftwaffe itself. The norm was to make constant changes to production models to improve them. You see the same thing with panzer production and, in many other industries.
German industry became accustomed to frequent modifications being called for by the military. The handwork system allowed for this to happen and the manufacturers were more interested in profit and keeping the military happy than in efficency.
On top of these problems was the retention of a high degree of parochialism among manufacturers and the military itself. The Luftwaffe in particular saw certain manufacturers as only suited for building certain aircraft types. When the manufacturers ventured off into new areas they were usually met with a high degree of resistance. Henschel is a perfect example. The Luftwaffe had serious reservations about using them at all as they were supposedly a "heavy industry manufacturing tanks and locomotives." The Luftwaffe attitude was sort of "what could a company that makes tanks and trains possibly know about building airplanes!"
If you also couple the use of large numbers of small sub contractors to the system you get a very high degree of inefficency that really cannot be easily eliminated. It certainly wasn't going to happen at the military's level.

 

It should be remembered that Luftwaffe was the first to switch over to fixed pricing on production aircraft from 1937 on. They also were the first to licence production of Junkers aircraft in the mid to late 1930s. So Wever could indeed increase production by fixing price and forcing the industry to find and eliminate the inefficency. Too much walking on eggshells on these issues, most histories of the economy of war note that mass production is facilitated by selecting small number of types to greatly increase numbers of mass production. No excuse for Germans/Hitler on this issue either, that was a political choice based on false premise of war in mid 1940s.

The History of the Spitfire Development

In a book "Hitlers Northern War' Adam Claasen, it reports the time between radar detection and squadron scrambled was 15 minutes for initial detection during this period [BoB]. To scramble massed fighters to intercept massed bombers took 10 minutes more based on BoB times that I've seen...either that or decoy probes could be used to trigger the RAF fighters prior to bomber groups reaching targets.

So intercept should be ~ 30 minutes to high altitude bomber and massed intercept would be @ detection range + 40 minutes. This doesn't included time to close with and manuever into position. The target bomber should move ~100 miles in that 1/2 hour. How close doest the Spitfire have to be when takeoff, in order to reach such targets?

Spitfire V range was listed 1.23 hour endurance max @ 320mph. Radius is usually 1/2 of 80% of this range [395miles], suggesting ~ 158miles maxiumum radius [30 minutes endurance radius]. But if 1/2 hour is spent climbing , whats the true radius of intercept? What would be the true radius of intercept with a climb to altitude of 10km in the 1/2 hour time frame?

What was the Radar detection range? Looking at the maps the radar range looks like 140 miles high altitude?

 

Can I ask the source for this?

There are some high altitude combat accounts at Spitfire Mk I versus Me 109 E

For example:

"At about 14.55 hours on the 13th August, 1940, "A" Flight took off to intercept 3 e/a flying from Chatham but no interception was made. On returning to land we were instructed to join up with "B" Flight which we did about 15.40. We intercepted about 15 to 20 Me.109's flying at about our own height (19,000 ft.) engaged about 5 with my section in a dog fight and noticed four above to the east at about 23,000. I climbed and after a dog fight shot down the rearmost which blew up and descended in flames. The remainder dived for France. I was then returning when I noticed four Me.109's at about 26,000 ft. I climbed and approached down sun and shot down another in flames. I saw it explode on the way down. I then started to descend when about 30 Me.109's tried to attack me, but as they were the same level I outclimbed them into the sun and attacked the nearest one of my pursurers."

"At approximately 1530 I was patrolling with my flight following B Flight when we were instructed to intercept enemy raid. I saw about 40-60 bombers heavily escorted by fighters. Some of the fighters were above us. We climbed to 28,000 feet and attacked down sun. On my first attack I fired a full deflection on an Me.110 which immediately threw out clouds of white smoke, apparently Glycol. I last saw it diving about 10,000 feet below still throwing out smoke but could not observe it further as there were many e/a in the vicinity. I climbed above them and opened fire on the rear one which tried to fire from a gun in his tail. I could not observe the effect of my fire as I was being attacked by five ME 109's from above. I managed to out climb them and attacked the rear ME with my remaining ammunition but observed no results. Returned and landed"

"I was leading the Squadron on patrol at 30,000 feet roughly over Chatham. I followed 41 Squadron down to 28,000 feet and then saw about 5 Me.109's directly above at 29,000 feet. I climbed up into them and they made for a layer of cirrus, through which I followed them. I increased revs. to 3000 and gradually outclimbed them and gave a 4 seconds burst into the belly of one enemy aircraft. Glycol streamed out of the port radiator and he went down in a shallow dive. I followed him down and gave a series of 1 second bursts at 100 yards, down to 3000 feet."

The lack of fuel injection caused problems with negative G. It did not cause problems at high altitude.

In a fantasy world where the Luftwaffe had as many heavy bombers as they actually had medium bombers, very little would change. The Luftwaffe was constrained in their bombing by lack of escorts. They could replace mediums with heavies, and drop a few more tons, but it won't have much effect on the outcome.

If they tried to bomb from higher altitudes, the reduced accuracy would actually make the Luftwaffe less effective, not more.

Heavy bombers at night would have made a difference, IF the Luftwaffe could find enough fuel for them, IF they could find enough spare parts, and IF they could build enough to replace losses.

But if the Luftwaffe has all this extra fuel, spares, crews and production, they would make a big difference to the medium bomber campaign, as well.

In other words, heavies don't really change things.

I don't quite understand what you are trying to get at.

Radar range varied greatly with weather, number of targets, over land or sea, altitude etc. Generally the south coast radars picked up the Luftwaffe forming up over France.

The RAF usually kept squadrons on patrol to meet the raiders. Take for example the diary of 303 squadron from the RAF web site:

1st September - Airfield patrol, 12 aircraft. Nothing to report
2nd September - 12 aircraft left to intercept raid (presumably a scramble)
3rd Sept - 12 Hurricanes on patrol, various vectors and patrol orders
3rd Sept - 9 Hurricanes patrolled Maidstone and Dover, met many friendly fighters
4th Sept - 2 separate patrols, no contact with enemy
5th Sept - Morning patrol, no contact made. Afternoon "After various sectors, S/Ldr Kellett, Red 1, at 22,000 ft, near Gillingham, saw AA across the Estuary and led Squadron to attack. " (sounds more like a patrol that encountered the enemy than a scramble)
6th Sept - "After various patrol orders the Squadron was over Western Kent and saw very large formations of enemy aircraft moving up from the coast to the east of them and above."
In the afternoon 2 separate airfield defence patrols, no contact made
7th Sept - "11 Hurricanes left Northolt 16.20. 9 Hurricanes landed Northolt 17.50 hrs onwards. Combat over Essex about 17.00 hrs." (this was the attack on London, and 303 were scrambled early)

I'm a bit confused as to the use of a Spitfire V, as we are discussing an alternative BoB. However:

The Spitfire V takes about 15 minutes to reach 35,000 ft, that's at a fuel flow of 84 gallons an hour. That's 21 gallons used on the climb. Add say 4 gallons for warm up and takeoff, 25 gallons used, 63 remaining.

10 - 15 minutes combat would use about another 15 gallons, meaning 48 gallons remaining. 5 miles to the gallon would be easily achievable, meaning 120 miles radius (the figure you give is for maximum cruising speed, rather than maximum range). However, that ignores the distance made up on the climb. 15 minutes climbing at 160 mph means about 40 miles covered, taking outbound radius to 160 miles. On the return, you can either divert to a closer base, or the 30,000 ft starting altitude will trade to well over 40 miles glide.

In other words, range isn't really a problem for intercepting German aircraft attacking Britain. The Channel isn't that wide even at it's widest point, German escorts have a much greater fuel problem.

 

With 88 gallons full tank and using standard 80% rule, then only ~70 gallons would be usable for intercept and return since the rest is reserve and combat. If you suggest 25 gallons to warm up and reach 35,000 ft that leaves 45 gallons to return @ 5 miles to gallon or 227 miles .

If we extend this to maximum, then the 70 gallons is divided between 5 miles gallon return and 2 miles gallon climbing, or 3.5 miles gallon average 245miles or a radius of 122 miles. Is that how you got 120miles radius?

But I read that radar range was anywere from 50-120 miles so this maximum range is not usable for front line squadrons, but works for vectoring in reserve rear area squadrons later....if there is time.

What were the climb to 35,000 feet figures for Hurricane and earlier Spitfires, since these would the planes that dominate the RAF BoB fleet?

Re patrol squadron, unless they can read the germans moves ahead of time patrols could never hope to cover daylight hours with only 1.4 hours maximum endurance. Even if they could fly 3 sortie per day thats still only 5 hours patrol coverage per plane per day. You'd need 3 fighters just to ensure one was flying at all times. Thats about 800 gallons of fuel per day to ensure one fighter was on patrol during daylight hours...whats 800 gallons in real figures, 3010 liters?

BTW if the Germans do build Ju-89 multi engined bomber, they would not build the 12 ton Ju-88 medium slant bomber. Since one was predicated on the loss of the other. Instead Ju-88 would have been built as it was originally intended to be, a schnell bomber weighing 7 tons full load clean in Zeostroer role replacing Me-110 and others in this role. With smaller plane /wings and same engines, it should top 350 mph and wingloading comparble to Hurricane, but with 3 times the endurance of the Me-110. So the Germans would have their long range strategic bomber and long range fighter escort.

 

Why 35,000 ft? That's above the absolute ceiling of the 109E, and the fuel situation is going to be even worse for bomber escort at that altitude, so the German bombers are going to be unescorted. And not even the B-29s tried bombing at that altitude. I don't think 35,000 ft is realistic.

However, time to 35,000 ft would be just over 21 minutes for the Spitfire II.

That's not maximum endurance. That's endurance at maximum cruising speed.

Minimum fuel consumption would be about 25 galls/hour at lower altitude, reducing with altitude.

800 imperial gallons is about 3600 litres. Looking at 303 squadron, it looks like something over 5 patrols per scramble.

At 7 tons, the Ju 88 would need wings of about 620 sq ft to equal the wingloading of the Hurricane, which is a bit bigger than the wings they had historically.

As to radical design changes, I think that's pushing it. The Ju 88 was barely ready for the BoB anyway, you'd have to change the design very early for it not to be delayed further.

Of course, with these German super bombers being developed, the British might just have changed their fighter priorities too. Rush the Merlin XX into production, build the Spitfire III. That's gives about 400 mph, and should be ready by the summer of 1940.

But all this is getting a bit too far from historical for my tastes. Luftwaffe 4 engined bombers in 1940 I can cope with, them operating at 35,000 ft, escorted by cut down, 350 mph Ju 88 fighters, is going a bit far.

 

"Sigh"

I know that, so did Wever and as Chief of Staff he intended to change that, something you overlooked in your reply.

Look in the German Military, the Chief of Staff holds the real power, they have the Authority to give orders.

Who ever gets that position has more power than the actual commanding officer. Goering won't be able to push Wever around like the others and Wever has the backbone to stand up to Hitler and once he explains that Hitler needs real strategic bombers for his war against Russia, Hitler will listen as Wever unlike other Generals will be giving him what he wants.

As for modifications, that can happen in a Assembly Line Industry as well, and field modifications will happen regardless so I don't see what you are trying to say.

 

Actually the Brits could. Although the ULTRA system was not perfected the Luftwaffes habit of sending long detailed operational orders by radio, sloppy radio & encyption procedures, and the other forms of singnals analysis allowed the Brits a lot of warning clues for bomber missions.

 

Spot on, Wever not being killed in 1936 and in charge of Germany's strategic heavy bomber programme would be in a very srtong position to most likely to oust Goring, could you imagine Wever in charge of the Luftwaffe during the BoB and having say at his disposal 500 to 700 four engine strategic bombers to attack British Industry, while having 2,000 medium bombers concentrate on the reduction of the RAF, it would be a role reversal as to when the Allies began their bombing offensive in mid 1942.

With the elimination of British Industry and Royal Air Force, Hitler would certainly have gone after Britain in an invasion. Seelowe would have succeded, and just imagine that plans of the proposed Lancaster, Halifax and Stirling fell into German hands could you imagine them in Luftwaffe service, Germany would wipe the Soviet Union of the map.

 

And also thank Providence for German Intelligence, who consistently couldn't find the right targets to bomb and wildly overestimated the damage which was being done.