"They're coming in too fast!"

NOMISYRRUC,
Why were German designers so insistent on using "coupled" engine designs to get higher horsepower? To me, this seems like an overly complicated solution.
 
NOMISYRRUC,
Why were German designers so insistent on using "coupled" engine designs to get higher horsepower? To me, this seems like an overly complicated solution.

Don't know. But to speculate, how about because they didn't have high octane avgas like the British and Americans.
 
NOMISYRRUC,
Why were German designers so insistent on using "coupled" engine designs to get higher horsepower? To me, this seems like an overly complicated solution.

Also looking at Wikipaedia (which I'm taking it with a pinch of salt) it seems that the problems with the DB606 and DB610 on the He 177A weren't the engines themselves, but the installation. It says that the DB606s on the He 119 and Me 261 didn't suffer from the same problems. However, as they were experimental aircraft that probably isn't a valid comparison.
 
I thought the Whirlwind had problems with crashing during maneuvering, when the slats failed. Not corrected until mid 1941, I thought?

If I may:
There was one aircraft that have problems with sats not extending simultaneously, that aircraft was not Whirly, but Bf 109, earlier versions, the Emil included. MTT redesigned the mechanism, that now included a metal rod, that made sure the slats will extend and retract in same time.

Plus, I've read that the Whirlwind was specifically designed for the Peregrine. Can it plausibly use anything else, without an extended redesign and testing program? And if not, when were the Peregrine's reliability issues fixed?

The Peregrine's reliability issues are probably blown over the proportions. The squadrons operating Whirlies were using the handful of produced engines within 3 years, that is not a sign of an unreliable engine on the aircraft in question.


So, how long might it take from somebody realizing the need, through redesign, modification and testing, to having two or three squadrons operational? Assuming no unforeseen problems arise, which I shouldn't think there would be.

Depends when Petter or someone else in his team realize that the original exhaust is more thouble than asset, leading from engine, into a single tube per block, exiting behind the engine. Same for the convoluted ram air intake. A quick glance on Bf 109D/E, 110, or P-40 prototype while reading Flight magazine should give a clue to an aircraft designer. Work commences, say, by early/mid 1939? So the 1st squadrons can receive aircraft by Spring of 1940.
 
AFAIK one of the things Udet bungled was the DB603 engine. According to Gunston in his aero engine encyclopaedia the Luftwaffe could have had aircraft with DB603 engines in large scale service during the Battle of Britain, which means to me an aircraft like the Ju 188 in service instead of the Ju 88, Do 217 in place of the Do 17Z and Me 410 in place of the Bf 110. I think that's a better way to give the Luftwaffe a qualitative edge in 1940 than trying to turn the He 119 into a practical combat aircraft.

OTOH I think the RAF could have had aircraft with Griffons and Vultures that worked in the BoB had the Air Ministry and aero engine industry done things differently, so the Luftwaffe wouldn't gain any advantage.

The workable DB 603 in 1940 is a double-edged sword. 1st - technicalities: what RPM we will have on that big engine in 1940, let's be generous and say 2400. Manifold pressure - 1.3 ata. Gives 1400 HP, give or take.
Let's install it it something now. Bf 109 - no. Bf 110 - again, no I'm afraid, not unless a major redesign is done, paying a hefty price in weight. How much of fuel for thirstier engines? After all is said and done, we're maybe at 350 mph - good, but no cigar. Less Bf 110 produced than historically.
The Do-17 will not became Do 217 with DB 603 instaled, again the major redesign is needed, that means delays in production, that means less Dorniers for BoB.
He 111? That might be a good idea, the bomber will still be slow-ish, but not that slow, still needs escort.
Ju 88 with bombs hanging out is still slow to go without escort.
UK is already out-producing Germany in 1940 in engines, can the Germans trade a small lot of DB 603s produced for a bigger lot of DB 601 that are not produced?

I'd agree with Wiking - for the LW's victory in the BoB, a whole new mental set-up is needed (escort policy, target prioritization, not thinikng that after Frnace is defeated you don't need increase in production, also more pilots are needed). As a techicality, have all of the Bf 109s outfitted with drop tanks, that would've meant plenty of problems for RAF, and have Bf 110s employed as low-level fast bombers.
 

NoMommsen

Donor
NOMISYRRUC,
Why were German designers so insistent on using "coupled" engine designs to get higher horsepower? To me, this seems like an overly complicated solution.
Why : getting more power (and a 'coulpled engine' was asked for by Göring, but he thought of 2 engines coulpe in-line) ASAP

'complication' : quite the difference m8 :)
To compute an engine behavior for power, stress on zylinders, bearings, valves, camshafts, etc. for a different (increase) volume or fire-timings when adding zylinders for a wished for power, is an awfull complicated thing. And in the end you only make educated guesses, hoping that on a test stand the thing lives - at least - partially up to your hopes ... and doesn't explode or break.
And it needs a damn awfull lot of time also.

The (just :D) mechanical problems of coupling engines is MUCH easier to adress. Esp. if you keep in mind, that the germans were rendered masters of gearing, gearboxes and the like in their time.
Was much quicker than develop a complete new engine

Also looking at Wikipaedia (which I'm taking it with a pinch of salt) it seems that the problems with the DB606 and DB610 on the He 177A weren't the engines themselves, but the installation. It says that the DB606s on the He 119 and Me 261 didn't suffer from the same problems. However, as they were experimental aircraft that probably isn't a valid comparison.
You're right. The He 177 probs with the engine were the too small nacells and space given to them without a good enough ventilation, causing overheating and - you never get any engine completly 'oil-dry' - then burning bright :p.

As you mentioned, in constructions tzhe let enough room and ventilation the engines worked quite well.
 
NoMommsen,

Okay, I take your point. But it sure seems better to push through and get a better engine, than resign yourself to perpetually messing about with gearboxes, etc.

I mean, no matter how well built they may be, they are still extra potential points of failure. And they still add to the maintenance burden.

But yah, if time is short and the pressure is high...
 

NoMommsen

Donor
Well, attached is a model of 'complicated' mechanics, being the (nightmarish)dream of an maintenence engineer, of an otherwise quite successfull airplane engine :D
Bristol Hercules

Bristol20Hercules20sleeve.gif
 
The workable DB 603 in 1940 is a double-edged sword. 1st - technicalities: what RPM we will have on that big engine in 1940, let's be generous and say 2400. Manifold pressure - 1.3 ata. Gives 1400 HP, give or take.

Let's install it in something now. Bf 109 - no. Bf 110 - again, no I'm afraid, not unless a major redesign is done, paying a hefty price in weight. How much of fuel for thirstier engines? After all is said and done, we're maybe at 350 mph - good, but no cigar. Less Bf 110 produced than historically.


The Do-17 will not became Do 217 with DB 603 instaled, again the major redesign is needed, that means delays in production, that means less Dorniers for BoB.


He 111? That might be a good idea, the bomber will still be slow-ish, but not that slow, still needs escort.


Ju 88 with bombs hanging out is still slow to go without escort.


UK is already out-producing Germany in 1940 in engines, can the Germans trade a small lot of DB 603s produced for a bigger lot of DB 601 that are not produced?

I'd agree with Wiking - for the LW's victory in the BoB, a whole new mental set-up is needed (escort policy, target prioritization, not thinking that after France is defeated you don't need increase in production, also more pilots are needed). As a technicality, have all of the Bf 109s outfitted with drop tanks, that would've meant plenty of problems for RAF, and have Bf 110s employed as low-level fast bombers.
I half-agree with your criticisms about putting the DB603 on the aircraft of the era. I fully agree with you agreeing with Wiking about the mental setup of the Luftwaffe and fully agree about the drop tanks for the Bf109.

I didn't write it in the post, but to get engines like the DB603 as early as possible the improvement in the mental setup that Wiking suggested is required. But I think it follows that if they don't cancel the DB603 (as Udet did according to Gunston), then it would follow that they would have developed aircraft capable of using them. The resulting aircraft would not necessarily be fanboy "Wonder Weapons" the improvements would be marginal, BUT IMPORTANT, the air warfare equivalent of "percentage tennis".

The Do-17 will not became Do 217 with DB 603 installed, again the major redesign is needed, that means delays in production, that means less Dorniers for BoB.
I wasn't actually suggesting fitting the DB603 to the aircraft of the era. I thought that new aircraft would be developed, which is why for example I said the Me 410 instead of the Bf 110. Admittedly I did suggest fitting the DB606 to the BoB aircraft of OTL in a different post, but I was being facetious.

However, AFAIK development of the Do 217 began before the Do 17Z, but it wasn't put into production until 1941 because sufficiently powerful engines were not available until then. However, if Milch (or someone equally good) was in charge of aircraft development and production instead of Udet and didn't cancel the DB603 then I think its feasible to have the Do 217 ready to be built instead of the Do 17Z. Even if this means fewer Dorniers, and I think it will not if Milch was in charge instead of Udet, then this is offset by a smaller loss rate and the Do 217s heavier bomb load.

UK is already out-producing Germany in 1940 in engines, can the Germans trade a small lot of DB 603s produced for a bigger lot of DB 601 that are not produced?
With the better mental setup I think they could do a one-to-one substitution of DB603s for DB601s engines and the heavier airframes. I think the stumbling block would be how to pay the Russians for the extra aviation fuel.

Someone who receives as bad a press as Goering and Udet is Schmid the head of Luftwaffe intelligence. Would it have made a significant difference to the BoB and Blitz if someone better than him had been in the post?
 
Whomever did not made the job of destruction the RAF & it's assets (includes, but not limited to fighter bases, fighter units once airborne/returning, radar/C&C network) and to be persistent in this is to be blamed. Whether Hitler, Goering, Schmid, or a combination. Eg. Germany was world leader development in shipborne radars, yet they failed to rate just how much radars mean for fighter aircraft-based defenses. Interservice rivarly should be also blamed? (Goering kinda 'returned the favor', unknowingly, by issuing just a trickle of Condors to help the KM - a major bonus to the Allied war effort)

The Do-17Z was not a new deveopment, but a modification of the Do-17, powered by 9-cyl radial engines, to accept the light enough DB 601A. If Germans do the switch from Do-17 to a brand new Do 217, how much does that harm numbers deployed in 1940?
The production of airframes for Bf 109E was outstriping the production of DB 601s in 1939.

Similar paralels can be drawn for other aircraft, Germany just started installing 1000-1200 HP engines (600 kg dry, give or take) on airframes designed for engines of 650-900 HP (450-500 kg dry), Do 17 included. Going for 1400-1600 HP engines that weight close to 1000 kg dry warrant new airframes, that means lots of time lost for production, and Germany is already outproduced by UK.
So I'm afraid that 1941 will be the time for the DB 603 to make it's mark in Fw 190 and Do 217.
 
Depends how many of DB 603 there is in 1941. The Do 217 was a far better bomb truck than Ju 88, with sizable bomb bay and fuel tankage. The Ju 88 with bomb tray, as it was experimented earlier in war, might also be interesting. Or, go with brand new Ju 288 + DB 603 - finally a bomber designed around bomb bay and fuel tanks, that should beat the Do 217 and souped-up Ju 88/188 in capabilities.
The big Heinkel will be just a fine bomber with four of plain-vanilla Jumo 211/DB-601/BMW 801, IMO. No dive bombing this time, I'm afraid.

Either bomber will still probably need the escort, the Fw 190 + DB 603 should be able to provide that. Just remember - drop tanks :)
 
Top