AHC: post-1942 Luftwaffe 'sanity options'

[Deleted member 1487]

... I don't even understand why the comparison...

There's a limit to what an engine can do, otherwise we could stuck a Merlin in a Sopwith Camel. The Me-109 first flew in 1935, which means pretty much all of it's fuselage, wings and tail were designed with early/mid 1930s knowledge of aerodinamics, structural design and manuractoring techniques. The P-51 was built in 1940, befiniting from all the advances made in the late 30s, such as the Meredith Efect. This, plus improved materials and construction techniques, gave it a huge head start.

Not to mention the impact of the highest octane avgas available in the world and and engine tuned to take advantage of that, while of course enjoying the advantages of the excellent RR two speed, two stage supercharger. At high altitude the drag effects of the aerodynamics was lessened due to thinner air, so that was less a factor than the engine power at altitude. Plus the Bf109 had a maneuverability advantage over the P51, at least per USAAF veteran accounts I've seen.

 

[Carl Schwamberger]

Eight pages here & what we have of any substantial value are:

Concentrate production on single engine types a year earlier, any twin engine production should be limited to limited numbers of one or two models.

Tweak the fuel supply so pilot training & sortie rates might be improved.

Rationalize pilot training a year relier.

More R & D for anti air defense. Maybe that will come up with something, maybe not.

 

[Paolo Giusti]

Net of sarcasm, we were talking about how to reach those goals.

Concentrate production on single engine types a year earlier, any twin engine production should be limited to limited numbers of one or two models.

Which engine and which airplanes?

Tweak the fuel supply so pilot training & sortie rates might be improved.

Rationalize pilot training a year relier.

How? With @tomo pauk diesel trainers? Convert land units to diesel engine?

R & D for anti air defense. Maybe that will come up with something, maybe not.

AAM, SAM, flak towers?

 

[Deleted member 1487]

More R & D for anti air defense. Maybe that will come up with something, maybe not.

In terms of that they would have benefited from our hindsight in developing the 'Pfielgeschoss' earlier, as the ultimate AA gun developed in the 1950s directly expanded from German late war research into the use of 'arrow' shells:
https://en.wikipedia.org/wiki/Green_Mace

If not that then something like the "Probert Rifling" system developed by the British and experimented with by the Germans by the end of the war:
https://en.wikipedia.org/wiki/QF_3.7-inch_AA_gun#Mk_VI

Like the Mk IV this was based on the 4.5 inch barrel design lined down to 3.7 inches, and using the 4.5 inch size cartridge. However, Colonel Probert changed the barrel to have gradual rifling: the rifling groove depth decreased to zero over the last five calibres of the barrel before the muzzle. This smoothed the two driving bands of a new design shell giving reduced air resistance and hence better ballistic performance, and causing far less barrel wear. The maximum ceiling for the gun was about 15,240 m (50,000 ft). It was mounted on the Mounting Mk IIA and therefore deployed in static emplacements only. In service from 1944 to 1959.

Not only did it reduce the wear on the barrel, extending barrel life by several order of magnitude, which was a huge problem especially by later war for German AAA, but it dramatically improve range while reducing time to target making AAA fire more accurate by a considerable amount. Not as good as FSDS rounds, but better than what they were using IOTL. The best part is they could use their existing 88mm guns (or in a pinch 75mm ones) and use a 20mm thinner shell (they already made some for their experimental discarding sabot shells for using 88mm AA) and get performance approximating that of the 128mm guns for much less cost (just in terms of the shells the 88mm ones used 1/4 the propellant charge).

Since the 128mm guns were getting 5 times as many kills per shell than the 88 then turning the 88 into a 128mm gun in terms of performance at a fraction of the cost would be an enormous saving/effectiveness increase. Add in the boost in performance of even larger guns like the 105mm flak using existing 88mm shells and you might well be able to increase performance more. Now, if they added in other performance enhancers, like the 'doppelzünder' shell, which relied on ROF and contact fuses to simplify gun laying and produce respectively things could be increased in performance even more.

I don't think even with hindsight the Germans could make sufficient numbers of functioning proximity fuses given that state of their electronics industry, so they couldn't reap those benefits, but they could enhance the performance of their munitions further though by the FLAK commander taking von Haack up on his offer to design more aerodynamic projectiles using his mathematical research into drag:
https://en.wikipedia.org/wiki/Nose_cone_design#Haack_series

He presaged what Gerald Bull would later work on artillery shell aerodynamics:
https://soapbox.manywords.press/2018/07/05/extended-range-full-bore-rounds/

With a 'sub'-caliber shell in a Probert rifling system that would have allowed for longer shells than usual, which means the ability to make very ballistically efficient shells, so despite the low weight of the rounds they could have better energy retention than bigger, heavier shells with blunter shapes.

If they could also figure out base bleed and add a tracer/fumer compound to deal with it then they'd be even further ahead. Since they already had worked out rocket assisted projectiles for their 150mm and larger artillery, it shouldn't have been difficult to use that research to equip AA shells had they wanted to.

Combining these ideas would pretty seriously upgrade their AAA performance at an overall serious cost savings.

 

[Coulsdon Eagle]

A large reason the V1 did less damage than expected was the use of the XXX Deception system to convince the Germans to move the aim point into empty country side. The first few months most hit inside London. After the deception op succeeded most fell on near empty farm land. Unfortunately the same could not be done for Antwerp & that city took a beating in the winter of 1944-1945. Lots of civilian deaths, military deaths, and industrial operations disrupted. Fortunately the port operations were unhindered.

Hence the reason behind the most bombed London Boroughs for the V1 being almost exclusively south of the Thames, with Croydon being the hardest hit.

 

[Carl Schwamberger]

Which engine and which airplanes?

Any of the 2-3 best. The point here is larger numbers of any quality item. Luftwaffee operational strength during 1942-44 fluctuated between 5000 & 6000 aircraft. Allied frontline strength rose from a bit over 6,000 to 20,000= in the ETO/MTO. The only way the Lw dragged out its resistance into 1944 was the concentration on a very few types, mostly single engine. Thats a big reason why they managed to move up from 40,000 airframes in 1942 to 85,000 in 1944. By comparison the US reached 105,000 aircraft in 1944, including near half multi engine types. If Germany moves to single engine models earlier it gets volume earlier.

How? With @tomo pauk diesel trainers? Convert land units to diesel engine?

Aside from focusing on the essential of pilot skills & leaving the well rounded airman out of it the training time is reduced. The Brits did this in 1939, turning out fighter pilots in less than 120 days. The Germans were still training 'airmen' with a year long syllabus well into 1942. More important is placing priority to fueling this training. Its painfull but it does not matter how much fuel is saved if the results are rookies with half the flight hours of their RAF counterpart.

AAM, SAM, flak towers?

This is the weakest. My thought was to throw more R & D at the wall & maybe more will stick. Maybe some sort of proximity fuse will turn up, or practical anti air missiles...[/quote][/quote]

 

[Carl Schwamberger]

Carl Schwamberger said: ↑
A large reason the V1 did less damage than expected was the use of the XXX Deception system to convince the Germans to move the aim point into empty country side. The first few months most hit inside London. After the deception op succeeded most fell on near empty farm land. Unfortunately the same could not be done for Antwerp & that city took a beating in the winter of 1944-1945. Lots of civilian deaths, military deaths, and industrial operations disrupted. Fortunately the port operations were unhindered.

Hence the reason behind the most bombed London Boroughs for the V1 being almost exclusively south of the Thames, with Croydon being the hardest hit.

The US AF considered their version of the V1, the Loon, to be accurate enough they ordered up 5,000 for use against Japan.

 

[Paolo Giusti]

The point here is larger numbers of any quality item.

It is risky, isn't it? What if Germans choose the wrong aircarft, like they did with Bf210? What you suggest? Dora, Bf 109 G?

Aside from focusing on the essential of pilot skills & leaving the well rounded airman out of it the training time is reduced. The Brits did this in 1939, turning out fighter pilots in less than 120 days. The Germans were still training 'airmen' with a year long syllabus well into 1942. More important is placing priority to fueling this training. Its painfull but it does not matter how much fuel is saved if the results are rookies with half the flight hours of their RAF counterpart.

Sorry, this is not clear to me: are you suggesting to reduce the overall training time but rise real flying hours?

 

[marathag]

The US AF considered their version of the V1, the Loon, to be accurate enough they ordered up 5,000 for use against Japan.

Unlike the Germans, the US got a basic beam rider guidance package installed, getting within 4 miles of target of its 100 mile range in early 1945

 

[tomo pauk]

Not to mention the impact of the highest octane avgas available in the world and and engine tuned to take advantage of that, while of course enjoying the advantages of the excellent RR two speed, two stage supercharger.

Fully retractable & covered wheels were advantage of the P-51 vs. Bf 109G, so was the layout of the radiator and layout of carb air intake. The installation of HMGs on both Fw 190 and Bg 109 cost 10+ km/h.
Mentioning of hi-oct avgas that Allies had is a red herring - German C3 was about as good as allied 130 grade fuel. The 150 grade fuel offered no advantages above rated altitude(s).
RR 2-stage superchargers were indeed a major asset - greatly increasing altitude power, compact & light, featuring an intercooler from the get go. Already the Merlin 61 was offering, above 25000 ft, 50% more power than Merlin 20 series and DB 601E, and perhaps 40% more than DB 605A of 1942-late 1943. Comment by Willy in mid-December of 1942 was: "...the superiority of Merlin 61 is obvious..."; the P-51B was powered by the improved V-1650-3 (bigger supercharger, improved S/C drive, greater allowed boost).
German tests concluded that coefficient of drag of wing profile (not of whole aircraft) of the Mustang was 0.0072, vs. Fw 190 at 0.0089, and Bf 109 at 0.0101.

We can see that P-51, especially with Merlin engine, was at a whole new technological level vs. what Luftwaffe was fielding.

At high altitude the drag effects of the aerodynamics was lessened due to thinner air, so that was less a factor than the engine power at altitude.

At high altitude, another source of drag becames ever-increasingly present - compressibility-related drag. Granted, it became a factor once speeds went above 400 mph?

Plus the Bf109 had a maneuverability advantage over the P51, at least per USAAF veteran accounts I've seen.

It should be so, the P-51 was a very heavy aircraft.

 

[Deleted member 1487]

Fully retractable & covered wheels were advantage of the P-51 vs. Bf 109G, so was the layout of the radiator and layout of carb air intake. The installation of HMGs on both Fw 190 and Bg 109 cost 10+ km/h.

Sure, but at what altitude is that speed penalty? The Bf109K was able to clean things up, but it's biggest boost was in the improvement engine and boost configuration.

Mentioning of hi-oct avgas that Allies had is a red herring - German C3 was about as good as allied 130 grade fuel. The 150 grade fuel offered no advantages above rated altitude(s).

Not really as I did say 'available', as the C3 fuel was not really available by Summer 1944 and prior was mostly saved for the Fw190, which required it for it's engines to work.

RR 2-stage superchargers were indeed a major asset - greatly increasing altitude power, compact & light, featuring an intercooler from the get go. Already the Merlin 61 was offering, above 25000 ft, 50% more power than Merlin 20 series and DB 601E, and perhaps 40% more than DB 605A of 1942-late 1943. Comment by Willy in mid-December of 1942 was: "...the superiority of Merlin 61 is obvious..."; the P-51B was powered by the improved V-1650-3 (bigger supercharger, improved S/C drive, greater allowed boost).
German tests concluded that coefficient of drag of wing profile (not of whole aircraft) of the Mustang was 0.0072, vs. Fw 190 at 0.0089, and Bf 109 at 0.0101.

We can see that P-51, especially with Merlin engine, was at a whole new technological level vs. what Luftwaffe was fielding.

Indeed.

At high altitude, another source of drag becames ever-increasingly present - compressibility-related drag. Granted, it became a factor once speeds went above 400 mph?

Do you have some info about what you're talking about? All I'm seeing on a quick search is the consequences of high altitude and lift penalties due to how thing the atmosphere is. Speed rises though the further up you go due to reduced drag so long as the engine gets enough atmosphere to keep up combustion.

It should be so, the P-51 was a very heavy aircraft.

Yeah, forgot it was about 1 ton heavier than the Bf109G.

 

[M79]

A) Stop experiments into rocketry/wunderwaffe immediately!

B) Standardize the air corps: one light fighter, one light bomber, one heavy fighter, one heavy bomber. One engine for fighters, one engine for bombers.

C) Coordinate R&D more - i.e. get the He280 flying and reassemble the original Hirth jet engine team with support from BMW and Jumo!

D) Copy aircraft designs/engines from France et al for German use, especially the Bloch MB162 and Farman F.222! From Smolensk the former can reach Ufa and Chelyabinsk. Go for the power plants (earlier Eisenhammer)!

E) Study Allied aircraft/airframes intensely for technical advances and coordinate with the Navy for better overflights - ask Japan about the DC-4e and get the Fw300 airborne as well!

F) Build more synthetic oil refineries wherever possible, ideally underground or very dispersed.

G) Invest in winter clothes.

H) Get the Siemens T-52 and T-43 up and running

I) Pay attention to Zuse's projects and see if he can get funding for a Z4, Z5, and maybe implement Plankalkul. CAD in WW2...

J) While the Fg42 is nice but just adopt and mass produce the Ribeyrolles Automatic Carbine 1918 and Fusil Automatique Modele 1918 retooled for German ammunition. Maintain the idea of selective fire using the Ribeyrolles as a basis.

 

[Deleted member 1487]

J) While the Fg42 is nice but just adopt and mass produce the Ribeyrolles Automatic Carbine 1918 and Fusil Automatique Modele 1918 retooled for German ammunition. Maintain the idea of selective fire using the Ribeyrolles as a basis.

Absolutely not. The Ribeyrolles was a simple blowback weapon that jammed constantly and was heavier than an STG44 with an effective range no better. So just use the STG44. Other than that yes, get rid of the FG42.
Plus the Ribeyrolles was scrapped after it failed to be accepted AFAIK, so there wasn't much info about it to work off of anyway.

BTW Plankalkul would not have enabled CAD in the modern sense. Plus it wasn't ready until 1945.
The first version of it took until the early 1950s:
https://en.wikipedia.org/wiki/History_of_CAD_software

 

[tomo pauk]

Sure, but at what altitude is that speed penalty? The Bf109K was able to clean things up, but it's biggest boost was in the improvement engine and boost configuration.

Looking at Fw 190A-8 (has HMGs) and A-6 (has LMGs), seems the speed penalty was at all atitudes - eg. 550 vs. 560 at SL, 645 vs. 655 at 6.5 km.
109K-4 shown that 20+ km/h can be earned vs. 109G-10 (the two have had same engines, DB 605D) via cleaning up the HMG installation + undercarriage being fully retractable & covered. The 109s using big-superchager versions of the DB 605 (like 605AS or 605D) again show a performance increase of another ~20 km/h vs. usual DB 605A above 7 km (= right where needed in 1943-44 in West Europe).
Obviously, all of the much improved DB 605s were too late to matter, while a 2-stage supercharged DB 628 was not proceeded with, and another 2-stage S/Ced engine, the DB 605L, never entered service being too late.

Not really as I did say 'available', as the C3 fuel was not really available by Summer 1944 and prior was mostly saved for the Fw190, which required it for it's engines to work.

C3 was certainly available by early 1942 until the end of the war. Granted, not in some amazing quantity, at least until the Allied managed to bomb the fuel infrastructure.

Do you have some info about what you're talking about? All I'm seeing on a quick search is the consequences of high altitude and lift penalties due to how thing the atmosphere is. Speed rises though the further up you go due to reduced drag so long as the engine gets enough atmosphere to keep up combustion.

Sharp rise of compressibility-related drag was a reason why people went to swept wings, since that was once way to delay onset of compressibility. Another way was to make wing as thin as possible - this is where Spitfire excelled, for example, as well as Tempest/Sea Fury and Spiteful. Or to use wing profile where thickes part of wing is at 40-50% of the chord (P-51, Tempest, Sea Fury, Spiteful).
Note sharp rise of wing's drag coefficient beyond 0.65 Mach. 0.65 Mach = around 440 mph at 30000 ft, but also 500 mph at SL (graph). Contrary to that, the profile drag rise was not that pronounced.
List of aircraft suffering the low mach limit at high altitudes includes P-38 and Westland Welkin, for example.
Prop-driven aircraft in last 50 years use the phenomena to set speed limits at low-ish altitudes, since there the onset of compressibility is delayed by ~50 mph vs. flying at 30000 ft and engine power is double, if not triple of what the ww2 service aircraft had.

 

[marathag]

Absolutely not. The Ribeyrolles was a simple blowback weapon that jammed constantly and was heavier than an STG44 with an effective range no better.

I'm pretty sure the Mle1917 Ribeyrolles used a rotating bolt, not all that different from the Model 8 Remington, other than more lugs, but with unlocking via oprod and gas port, rather than the long recoil of the Rem

 

[Deleted member 1487]

I'm pretty sure the Mle1917 Ribeyrolles used a rotating bolt, not all that different from the Model 8 Remington, other than more lugs, but with unlocking via oprod and gas port, rather than the long recoil of the Rem

Per Wikipedia it's a straight blowback system:
https://en.wikipedia.org/wiki/Ribeyrolles_1918_automatic_carbine

 

[marathag]

Per Wikipedia it's a straight blowback system:
https://en.wikipedia.org/wiki/Ribeyrolles_1918_automatic_carbine

Just looked up the mle1917, that's gas operated, as was this
https://en.m.wikipedia.org/wiki/Chauchat-Ribeyrolles_1918_submachine_gun

 

[Hammerbolt]

What about a proper parachute and drop gear for the paras? The poor fallschirmjägers had to drop like a sack of potatoes, carrying nothing bigger than a pistold... why this was ever decided I never could understand...

 

[Paolo Giusti]

What about a proper parachute and drop gear for the paras? The poor fallschirmjägers had to drop like a sack of potatoes, carrying nothing bigger than a pistold... why this was ever decided I never could understand...

Fallschirmjägers were destroyed in Crete in June 1941, POD is in Novembre 1941.

 

[Deleted member 1487]

Just looked up the mle1917, that's gas operated, as was this
https://en.m.wikipedia.org/wiki/Chauchat-Ribeyrolles_1918_submachine_gun

The Mle1917 is different than the automatic rifle Ribeyrolles, same with the 'smg' ribeyrolles.

That 'sub'-machine gun (not sure how it could be called that since it used full powered 8mm Lebel ammo) had to because of the ammo choice.