Much increased co-operation within Axis countries in technical and tactical matters?

[Koopernic]

I know of a few examples of military hardware where a gizmo was copied.

But looking at say the Bf 109 and would I make a copy. Nope. But the gunsight may be of interest. Cannon installation, radio. Fuel injection, slats.

Maybe I look at the slats and think the Seafire could use that. So not copying but simply taking ideas.

Slats would be interesting and might help. Messerschmitt was very good at slats to the point that the first XP-86 Sabres had slat hardware salvaged from the Me 262.

First two notes:
1 When slats deploy they do not increase the coefficient of lift. What they do is allow the wing to increase the angle of attack by about 55%-60% (from 15 degrees to about 22 degrees) before stalling thereby allowing increased coefficients of lift which are essentially linearly proportional to the angle of attack. There is no heavy 'snatching' when the slats deploy. There is a slight moment change that can pitch the nose a little forward (a good thing) ut no immediate increase in lift. The downside of this 55% increased lift is that the L/D ratio deteriorates about 55% compared to getting the lift from a larger heavier wing.
2 One RAE report on captured Me 109E talk of uneven slat deployment 'embarrassing' the Me 109E. I think this is a case of pilots being unfamiliar. Nevertheless the Me 109F had a completely revised slat mechanism using tracks that deployed evenly and smoothly.

Now, as to the nature of wing stall characteristics depending on planform:
1 Rectangular planform has a favourable stall progression. The stall begins at the wing roots and progresses out toward the ailerons.
2 Trapezoidal planform (eg Me 109) has an unfavourable progression. The stall begins at the win tips thereby making the ailerons ineffective. Hence the Slats.
3 Elliptical planform (eg Spitfire) has an even stall progression where both the tips and roots stall simultaneously. The spitfire had thinner wing at the tips and these stalled earlier so the stall progression would have been unfavourable but for wing twist.

The cure this problem the spitfire had about 2.5 degree of washout twist from the wing outboard of the undercarriage attachment. This gave a nice progression of stall that the pilot could sense.

There is also the effect of propeller wash to consider as the prop slipstream means the inner wing is not necessarily at the stall angle as the angle of attack would suggest.

One problem the Spitfire would have is that the structure consists of a main spar at about 1/4 chord (where the lift is) with a thick leading edge skin to create a D structure that was very efficient and gave a lot of space in the leading edges. The secondary spar near the trailing edge didn't carry much load and it seems was there to provide torsional rigidity so that the ailerons didnt twist the wings. Putting big holes in the leading edge would require some engineering. There was some work in getting the Hispano to fit.

However slats on a Seafire, perhaps with reduced washout, would
1 Considerably increase angle of attack before a stall.
2 However this would require a higher angle of attack thereby effecting visibility on a carrier approach and even requiring a taller undercarriage. Rather than using it to lower approach speed the slats would best be used to create a much greater gap between approach and stall speed adding greatly to safety.
3 The spitfire had good spin/stall characteristics but it could still flip a wing. The slats would completely eliminate that.

As far as I can tell the Seafires needed a more robust undercarriage, shock absorbers that can absorb a higher sink rate yet not bounce the aircraft off the deck and probably a taller tail to improve low speed handling.

The slats would add some weight and drag though by reducing washout could reduce drag a little and even increase the Spitfire incredible critical mach. The increased lift at higher alpha would come at the expense of increased drag from a reduced L/D ratio so the turning circle would reduce it wouldn't be as much as expected and would slow the aircraft unless more power could compensate.


Adding some kind of fowler flap or double slotted flap rather than just split flaps would be better as these add lift without requiring a higher angle of attack. Both slats and fowler flaps would be even better. The slotted flaps or fowler flaps allowing a reduction in approach speed and the slats adding safety margin.


Roughly a fully slated wing had 50% more CLmax which that would lead to an inverse square root reduction in stall speed. 1/sqrt(1.5) so 82% i.e. 18% reduction in stall speed. Ultimately you would probably adjust other factors as well. A half slated wing can get rid of 2 degrees of washout which if the stall was at 16 degrees would be roughly 1/2 x 2/16 ie 1/16th increase in lift or about 6.25% more if you consider that the wing would still work with the root stalled, and the the stall would tend to develop at the slat junction and travel ineard and propwash would keep the alpha low less if you consider the taper reducing area on the outboard sections it may be a lot more. I think its probably more than this.

 

[Greyman]

Had Britain pushed hard against the Kreigsmarine to stick to Versailles then no Tirpitz.

All things considered -- was the fact the Germans spent so much money/resources on capital ships an overall benefit for the Allies?

 

[Koopernic]

All things considered -- was the fact the Germans spent so much money/resources on capital ships an overall benefit for the Allies?

Probably. Instead of 4 battleships there could have been 12 additional Hipper Class cruisers for almost the same tonnage. Ships that could easily outrun any RN battleship and were almost twice as heavy as the typical RN cruiser and whose powerful 8 inch guns were still able to engage a battleship, their range was well beyond the optical horizon. I'm not saying they would be taking on RN battleships but they would probably be a better system of raiders. In fact if it were not for the anglo-german naval treaty the Germans would have built more tonnage but almost all of more cruisers and likely less if any battleships. The Hipper/Prinz Eugen cruisers would likely have evolved to much higher standards. Overall Britain benefited by restricting tonnage.

The Biggest German failure was the lack of long range maritime aircraft to support the ships and the lack of long range fighters and bomber aircraft to protect them a fair distance out to sea. No Ju 89/Do 19, He 177 or Ju 288 or long range escort fighter of some kind. A little support from Fw 200 and Ju 290.

 

[tomo pauk]

He 100 with I-F Delta (air-cooled V12 engine), as it might've looked if made or assembled in Italy instead of the Ambrosini SAI lightweight fighters (the most verifiable data gives 575 km/h on 750 HP for the SAI 207):

 

[tomo pauk]

He 100 + Sakae power. Not as trim looking as the V12-powered He 100, due to the deep chin dictated the a taller engine (5 in difference vs. DB 601A). Perhaps made by Aichi or Yokosuka as a land-based interceptor for the Navy (thus no Raiden), or perhaps made by Kawasaki for the Army.

 

[tomo pauk]

A new piece of kit - at the time - was the French G&R 14R engine. It has just been made and installed on the MB.157 prototype, when France collapsed. When Germans tested the 14R-4 and -5 (otherwise same engines, but with opposite rotation), they measured the 30 min power of 1320 PS at 5.95km; for comparison, the BMW 801A and C were doing 1310 PS at only 4.4 km altitude for 30 minutes. So perhaps ship some tooling to the Piaggio factory, and install the engine on Reggiane or Fiat fighter, or on a bomber desing?

 

[The Basket]

The Hippers were ok heavy cruisers but nothing special. No real advantage over a County Class.

Odd how the Germans intended to make the same mistake as in ww1 by trying to build up a surface fleet to take on the RN. Sheer dumbassery.

Bismarck was a major concern as it was much faster than the majority of battleships the RN had. Even faster than the KGVs. So that why Hood had to engage.

One could argue the RN had to use more resources to sink the Bismarcks than the Germans used to build them so it's an attrition win.

The main killers of the Kreigsmarine were auxillary cruisers and submarines so that's where my Reichmarks would go.

The Juene Ecole v Kantai Kessen debate rumbles on!

 

[Shortround6]

A new piece of kit - at the time - was the French G&R 14R engine. It has just been made and installed on the MB.157 prototype, when France collapsed. When Germans tested the 14R-4 and -5 (otherwise same engines, but with opposite rotation), they measured the 30 min power of 1320 PS at 5.95km; for comparison, the BMW 801A and C were doing 1310 PS at only 4.4 km altitude for 30 minutes. So perhaps ship some tooling to the Piaggio factory, and install the engine on Reggiane or Fiat fighter, or on a bomber desing?

Too new, the engine development may not have been completed until 1942, accounts differ.
There may not have been any production tooling. You can't build a 14R using 14N tooling. 14R used a three bearing crankshaft while the 14N didn't use a center bearing. New crankcase, new crankshaft. quite likely new cylinders and heads with more finning and so on.

only two or three planes flew during/ just after WW II with the 14R engine.

 

[Shortround6]

The main killers of the Kreigsmarine were auxillary cruisers and submarines so that's where my Reichmarks would go.

ANd the RN could alter their building program/s accordingly. More light cruisers with 6-8 six in guns. More destroyers and/or escort destroyers/sloops/frigates.

Trying to invade Norway with auxiliary cruisers and U-boats might not have gone well

 

[The Basket]

The Norwegian campaign went badly for the Kreigsmarine anywho.

Vanguard was constantly delayed for that very reason of having to build ASW vessels.

The Germans were going for Jutland 2 and then had to go Jeune Ecole by default. But they gave Jeune Ecole a full on good try. And they certainly did plenty of damage.

Even in battles against warships, the subs sank more RN carriers and battleships than the German surface fleet.

Maybe a discussion of what the Kreigsmarine should have been or even what the Kasierliche Marine should have been or, God Forbid....the Reichsmarine....should the Marinefliegerkommando operated Starfighters? So many questions!

 

[tomo pauk]

Too new, the engine development may not have been completed until 1942, accounts differ.
There may not have been any production tooling. You can't build a 14R using 14N tooling. 14R used a three bearing crankshaft while the 14N didn't use a center bearing. New crankcase, new crankshaft. quite likely new cylinders and heads with more finning and so on.

only two or three planes flew during/ just after WW II with the 14R engine.

Be it as it was, it was a far more 'finished' and realistic piece of equipment than any of the newly-fanged V or X engines at Fiat, ditto for the Piaggio engines like the P.XV of 18 cylinders.
Italian industry lacked, among other things, machine tooling. G&R tooling can come in handy, even if we can't talk about a complete production line for the G&R 14R engines.

 

[Shortround6]

Actually Piaggio was making a lot of Gnome-Rhone engines under licence. Or was developing engines based on Gnome-Rhone engines they had previously licenced.

One big clue is the 146mm X 165mm cylinder size.

Gnome-Rhone tooling sent to Italy might very well have helped production of existing Piaggio engines. It was unlikely to produced engines any more advanced than Piaggio was already making.
Italians were probably more fuel limited than any of the other major powers leaving increased boost pretty much out of the question. That leaves increased RPM (bearing and iol technology) and either more cylinders (helps with increased rom) or larger cylinders (hurts trying to increase rpm) as the only paths to high powered engines.

Gnome-Rhone had been working on an 18 cylinder in the mid/late 30s but gave up on it in 1939.

Used the same size cylinders as the Bristol Pegasus (146 X 190) but two valve heads.
Wiki says it ran at 2170 rpm. It only weighed 1623lbs for a 3310 cu in (?) engine. (something seems off there)
Another source (1938 Jane's) says 180mm stroke.

Piaggio 18 cylinder engines may have followed Gnome-Rhone a bit too closely?

In any case the Me 323 program used just under 1200 G-R engines and since they either came out existing French aircraft or were built new (more likely for most) shipping the tooling to Italy would have impacted German air lift and/or training.

 

[tomo pauk]

Actually Piaggio was making a lot of Gnome-Rhone engines under licence. Or was developing engines based on Gnome-Rhone engines they had previously licenced.

One big clue is the 146mm X 165mm cylinder size.

Yes, thank you.

In any case the Me 323 program used just under 1200 G-R engines and since they either came out existing French aircraft or were built new (more likely for most) shipping the tooling to Italy would have impacted German air lift and/or training.

Germany also sent both engines (DB 601/605 series) and whole aircraft (Bf 109, Ju 87) to Italy. With timely increased Italian production, the need for Germans to prop up the Italians by sending them actual hardware should be toned down.

 

[Shortround6]

The G-R 14R first flew in March of 1942 in the Bloch 157, which is way too late to give to the Italians and expect anything to come of it.
2nd plane to use the engine didn't fly until Feb 1945, the Bréguet 500 Colmar twin engine transport.

Shipping G-R production machinery to Italy will increase Italian production, after a building is built to house it. It is installed and work force trained to use it.
However the G-R 14N engine isn't that much different than the late model Piaggio 14 cylinder engines so there is not the increase in overall performance of Italian fighters that the DB engines gave.

It was possible to do it, I just don't know what the net gain would have been.

 

[Glider]

The Hippers were ok heavy cruisers but nothing special. No real advantage over a County Class.

Odd how the Germans intended to make the same mistake as in ww1 by trying to build up a surface fleet to take on the RN. Sheer dumbassery.

Bismarck was a major concern as it was much faster than the majority of battleships the RN had. Even faster than the KGVs. So that why Hood had to engage.

One could argue the RN had to use more resources to sink the Bismarcks than the Germans used to build them so it's an attrition win.

The main killers of the Kreigsmarine were auxillary cruisers and submarines so that's where my Reichmarks would go.

The Juene Ecole v Kantai Kessen debate rumbles on!

I agree with the vast majority of this posting apart from the auxiliary cruisers. With better communications and widespread use of aircraft the days of the auxiliary cruiser were over. Very effective in WW1 but not WW2.
Few would disagree with Germany betting the farm on submarines from the start of WW2 instead of starting the war with a handful of subs. Regarding the Hippers they were very good on paper but not in practice, being overengineered and very unreliable.
As for coordinating with Japan, again few would disagree with the view that had the Japanese used German tactics and strategy, the USA would have had a far more difficult task.

 

[tomo pauk]

The G-R 14R first flew in March of 1942 in the Bloch 157, which is way too late to give to the Italians and expect anything to come of it.
2nd plane to use the engine didn't fly until Feb 1945, the Bréguet 500 Colmar twin engine transport.

We don't know how much of time was wasted by Germans between 'our stuff in development/pipeline is better anyway' and 'oh cr@p, our newest stuff is either too late or we can't get enough of it, so let's see how good is the 14R actually'.
Italians know that their stuff is either outdated, or unreliable (like the 18 cyl engines, especially from the Alfa Romeo), or it exists only in paper.

Shipping G-R production machinery to Italy will increase Italian production, after a building is built to house it. It is installed and work force trained to use it.
However the G-R 14N engine isn't that much different than the late model Piaggio 14 cylinder engines so there is not the increase in overall performance of Italian fighters that the DB engines gave.
It was possible to do it, I just don't know what the net gain would have been.

It might be far easier to make a new building, than to came around with machine tooling that is needed for increasing engines' production. At least that was the thing with Soviet factories when evacuated, that in many cases started making stuff even before there was a roof above the machine tooling.
French workers might be easier persuaded to move in Italy for at least a few months, than they be willing to go in Germany or to work under German supervision in France. So the net gain might be that total supply of useful engines for Italy and Germany is increased from winter of 1940/41 on.

 

[The Basket]

If you look at the missions of the German auxillary cruisers like Atlantis and Pinguin then plenty of action and far more useful than the Panzerschiffe.

We must remember that in 1939 there was no French or Norwegian coast bases so any German U- Boat would have to go through the English Channel or around Scotland. Both would suck.

My view is that an Auxiliary cruiser can use false flags and disguises to pass through a possible blockade and then stay on station for longer. Not saying Atlantis or Pinguin was winning wars but sometimes been a total pain in the posterior and setting up a wild goose chase is worthwhile in itself.

The main goal of the surface raider is not to sink ships but to cause cancellation and delays of shipping and to cause the enemy navy to send disproportionate amount of forces to counter.

This perfectly suits a 1939 Kreigsmarine and probably as good as can be hoped for.

 

[Shortround6]

With both the Panzerschiffe and the auxiliary cruisers the British had to plan for both and build accordingly.
And assign convoy escorts and form convoys accordingly.

The British used 56 Auxiliary cruisers of their own, including the Jervis Bay and Rawalpindi. They also used 16 ocean boarding vessels. There were also 8 seagoing auxiliary AA vessels.

And with not Panzerschiffes the British might have built more of these.
"The Arethusas were a smaller version of the Amphion group of the earlier Leander class, having the unit machinery layout and two funnels of the former. The design was judged to be the minimum required for a "trade route cruiser" to counter the threat of the auxiliary cruiser over which, even with their reduced armament, they would enjoy a comfortable superiority."

5,220 tons standard load, Six 6in guns.

The British also had a crap load of old WW I cruisers that could be used for trade route protection even if somewhat short ranged.

Are 10 raiders at sea twice as disruptive than 5 raiders at sea or only somewhat more disruptive?

 

[The Basket]

The British in the early days didn't know how many raiders were at sea....could be 5 could be 20.

Every cruiser built is one less Flower class and less crew for ASW.

It all adds up....if you delay 12 ships for a month you have effectively removed one ship for a whole year without firing a shot.

Plus auxillary cruisers did sink enemy warships and could act as submarine tenders.

Of course every action has a reaction and British rule of the waves will eventually mop up the auxiliary cruisers but less ships in the Mediterranean, less ships at Singapore, less ships on the atlantic convoys.

 

[Shortround6]

The British built 10 cruisers with twelve 6in guns after the Arethusa class,
They laid down 11 Didio's in 1937-39.
They laid down 11 cruisers of the Fiji class in 1938-39 (9 or 12 6 in guns)
The five Bellona class cruisers were laid down in 1939-40 but planned earlier.

If the Germans build fewer surface warships in the late 1930s the British adjust their building programs to suit.

The British from 1937 on also laid down 16 Tribal class destroyers, (11 more were built later)
1938 saw the first of the 24 J, K and L Classes,
Dec of 1939 saw the first of the 16 L and Ms launched.

The French navy was supposed to counterbalance the Italian navy in the Med.

The Italians completed six light cruisers (eight-ten 6in guns) from 1935 until 1942.
The French had also completed 6 light cruisers (nine 6in guns) during 1935-1938.

Any major shift in U-boat construction would have seen a shift in British warship construction.
Three of the Hunts were launched before the end of 1939 so design and construction had started much earlier.
A further 28 Hunts were launched in 1940.

Armed freighters are no match for real warships on average, Kormoran vs Sydney notwithstanding.