Production rate versus type effectiveness (1 Viewer)

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Talking about liquid cooled inlines...my preliminary research seems to be that both the liquid cooled inlines and the planes derived from them were cheaper, pound for pound, than the air cooled radials and the planes derived from them.

Is this a fact? Can forum members prove or disprove this either way?
 
While its true that the Sabre was liquid cooled horizontal H-type, in practical terms it was very much like a radial engine. The engine as a whole was considerably larger in frontal area than existing, ordinary V-type inlines, and its weight was also akin to that of typical high-performance radial engines (perhaps on the whole even heavier, given that the it would also need radiators, piping and considerable amount of coolant to be carried around, though I have not seen yet figures for the complete Sabre "power egg").

While the Sabre was indeed very heavy, around 1070 kg dry, its frontal area wasn't really comparable to that of a radial, at least one of similar power.

It occupies its own middle ground in between the V-types and the radials. Sort of appropriate, as it was really a one-of-a-kind during the war.

V-type engines had frontal areas ranging from about 5.5 sq ft (DB 601, M105) square feet, up to 7.9 sq ft (late model Griffons). Most were around 5.9-7.5 sq ft. Merlin 66 was 7.5 sq ft, DB605 was 6.9 sq ft.

The Sabre had a frontal area of 8.8 sq ft, so about 17% more frontal area than the Merlin and about 28% ( :shock: , hadn't realised it was that much) bigger than the DB605.

Radials went from 10.6 sq ft for the Sakae 21 all the way up to 17.0 st ft for the R-3350. Most were about 13.5 sq ft to 16 sq ft.

So, radials have from 20% to 94% more frontal area than the Sabre. Most fighter radials (P&W R-2800, 801D, Ghnome Rohne 14, Klimov M-28) had about 50% more frontal area than the Sabre.

Of course, the RAE decided that wing radiators were too susceptible to battle damage, forcing Camm to put the ruddy great radiator chin on the Typhoon and Tempest. This probably ended up doubling the frontal area anyway... :oops:

PS. Thanks to Krieghund for providing me with the frontal areas of the various WW2 engines, from the engines sub-forum. :D
 
This forum contains more WWII aviation historical source data then anyplace else I know of. I've been mining it for information for quite some time. It was time to quit lurking and say hello. Now if only I could find a suitable color picture of a Fw-187 for my Avatar. :)
 
If we consider pure cost/effectiveness of a fighter, some Soviet fighter may have been be the the best, perhaps the Yak-3. Very basic equipment, light, cheap (wooden) materials, easy to fly, but still impressive performance.

Operationally , the biggest drawback was usually inadequate range, so considering that the P-51 might be a winner.

Of the bombers, I would choose the Lancaster.
 
If we are considering bombers then I like the American A-20. It offers a lot of performance for the price.

1941 Prices. Assume 2.5 marks = 1 U.S. dollar.
$106,260. He-111H.
$122,780. Ju-88A.
$136,813. A-20.
$180,031. B-25.

Despite being classified as a light bomber by the U.S. Army Air Corps, the A-20 payload (max weight minus empty weight) is similiar to the B25, B26, Ju-88 and He-111. The A-20 is faster then the competition, providing greater survivability. Why didn't the U.S. Army Air Corps use the A-20 rather then the slower and more expensive B-25?
 
If we are considering bombers then I like the American A-20. It offers a lot of performance for the price.

1941 Prices. Assume 2.5 marks = 1 U.S. dollar.
$106,260. He-111H.
$122,780. Ju-88A.
$136,813. A-20.
$180,031. B-25.

Despite being classified as a light bomber by the U.S. Army Air Corps, the A-20 payload (max weight minus empty weight) is similiar to the B25, B26, Ju-88 and He-111. The A-20 is faster then the competition, providing greater survivability. Why didn't the U.S. Army Air Corps use the A-20 rather then the slower and more expensive B-25?

I like your choice and reasons - however, one issue with $ to marks is that it may not be a good barometer in costs or efficiency of production. Wish labor hours for all the questioned a/c were available.

Example (with no data).

If a riveteer in US is paid a $1/hour and the same skill set in Germany commanded $0.50/hour but the Ju 88 and B-25 had about the same number of rivets - the COST for the same labor on B-25 is 2x but the hours to buck the rivets are about the same.
 
A20A load (not payload, like your max-empty) 5500 pounds
B25B load (" ") 11000 pounds
B26A load (" ") 11500 pounds

that are for '41 models
 
A20A load (not payload, like your max-empty) 5500 pounds
B25B load (" ") 11000 pounds
B26A load (" ") 11500 pounds

that are for '41 models

I believe dave was referring to max useful load vs bomb load. The A-20 was essentially a two person ship so 400 pounds of its 5500 'load' (if that is the number) is then a combination of fuel, ammo and bombs - to be modified aginst the needs of the mission.

The B-25 and B-26 typically carried 7-8 crew members for example so the useful payload split between bombs, ammo and fuel is 1600 pounds less than the difference bewteen Max and Empty.

I don't offhand know which figures are right and whether or not Empty means no guns, fuel, consumables and crew - or some other definition.
 
An idea - we know that a radial re-engined as an inline gains in weight, but usually has a speed increase and an increase in range. ( XB-38 )

What would have been the performance in speed and range if the 1600 hp radials of the A-20 had been replaced by 1600 Merlins?
 
An idea - we know that a radial re-engined as an inline gains in weight, but usually has a speed increase and an increase in range. ( XB-38 )

What would have been the performance in speed and range if the 1600 hp radials of the A-20 had been replaced by 1600 Merlins?

Depends on the Merlin. The A-20 was not a high altitude mission bird so the best probable choice is the 1650-7 which had better middle altitude performance than the -3.

Second, the Hp was in the same range so a jump in speed is dependent on other factors.

The most probable opportunities for better performance depends on how much parasite drag is reduced with new engine nacelles, how much weight must be added for cooling system and how much more range could be obtained with 'all in' design changes. Would doubt noticable speed increase.
 
That's what I've been wanting to ask you Drgondog - all the facts i can access on the XB-38 say that its efficient cruising speed increased by about 10% and its range by about 20%. Given that the biggest drag factor in the B-17 design were the thick wings and protruding turrets, it seems to me that the main reason for the range increase was not the lesser drag of the smoother inlines, but the fact that the Merlin consumed less fuel per hp output at optimum cruising speed. Am I on the right track?
 
That's what I've been wanting to ask you Drgondog - all the facts i can access on the XB-38 say that its efficient cruising speed increased by about 10% and its range by about 20%. Given that the biggest drag factor in the B-17 design were the thick wings and protruding turrets, it seems to me that the main reason for the range increase was not the lesser drag of the smoother inlines, but the fact that the Merlin consumed less fuel per hp output at optimum cruising speed. Am I on the right track?

yes
 
Payload will vary depending on exact aircraft model and equipment carried. But I think these payloads are in the ball park.

He-111H
WW2 Warbirds: the Heinkel He 111 - Frans Bonn
14,000 max
8,680 empty.
----------
5,350 payload.
2,000kg bomb bay.
The heavy weight among medium bombers until the Do-217 entered service.

Ju-88A4
WW2 Warbirds: the Junkers Ju 88 - Frans Bonn
14,000 max
9,860 empty.
----------
4,140 payload.
500kg bomb bay.
Bomb bay size is pathetic. It scarcely qualifies as a bomber. How did Junkers get away with this?

A20A.
WW2 Warbirds: the Douglas A-20 Havoc - Frans Bonn
10,660 max
6,827 empty
-------------
3,833 payload.
2,000 lb bomb bay.
Decent size bomb bay + excellent performance is a winning combination in my opinion.

B25C.
WW2 Warbirds: the North American B-25 Mitchell - Frans Bonn
12,909 max
9,072 empty.
----------
3,837 payload.
3,200 lb bomb bay.
Total payload is almost identical to the A20. However the bomb bay is larger.
 
The Ju 88 was originally designed as a fast bomber with a very thin body, 2 men crew and close to no defensive armament (1 light machinegun). Very similar to what the Mosquito later would become. There were always problems with the bomb bay being too small for 250 let alone 500 kg bombs. Nevertheless it could carry up to 28 50 kg bombs internally (1400kg). Maybe you should be a little more respectful and search twice before calling one of the best planes of the war pathetic?
 
Newbie here - I just joined but your thread touches on a subject dear to my heart - evolution of weapon platform in wartime - and - increase of unit costs.

In general terms - the US had the P-39 Cobra and the P-40 Warhawk in operational use in 1939 - the P-38 was just arriving in service.

The P-39 and P-40 were both 'inexpensive' designs. These 2 airplanes were used widely - but formed the bulk of the US lend-lease fighter deliveries to the USSR.

Pre-Merlin versions of the P-51 were also in the same cost-per-unit range.

The P-38, P-47 and Merlin-powered P-51 were ALL considerably more expensive planes. And were used widely the the USAAF (and the P-47 by the RAF in Asia).

My point is that the US gave their pilots the best - and did well with it - but the recipients of the lend-lease P-39's and P-40s were able to find ways and means to use them very effectively.

Case in point - the "inexpensive" P-39. The Russians got the bulk of production and the plane continued to evolve to reflect the "client's" needs -- the USSR. Clearly the P-39 served a valued niche role and the platform evolved into the "hot" P-63 Kingcobra. Again the bulk of production gpoing top the USSR.

The US Air Museum in Ohio has a website with great spec sheets of many US-made WW2 aircraft - check it out. Also - the production totals on the Compare Aircraft website is very useful for production stats. #1 - The Il Sturmavik.

I'd love to hear from anyone with P-39 combat experience ... Chuck Yeager included.

Chairs,

MM
Toronto
 
Newbie here - I just joined but your thread touches on a subject dear to my heart - evolution of weapon platform in wartime - and - increase of unit costs.

In general terms - the US had the P-39 Cobra and the P-40 Warhawk in operational use in 1939 - the P-38 was just arriving in service.

The P-39 and P-40 were both 'inexpensive' designs. These 2 airplanes were used widely - but formed the bulk of the US lend-lease fighter deliveries to the USSR.

Pre-Merlin versions of the P-51 were also in the same cost-per-unit range.

The P-38, P-47 and Merlin-powered P-51 were ALL considerably more expensive planes. And were used widely the the USAAF (and the P-47 by the RAF in Asia).

My point is that the US gave their pilots the best - and did well with it - but the recipients of the lend-lease P-39's and P-40s were able to find ways and means to use them very effectively.

Case in point - the "inexpensive" P-39. The Russians got the bulk of production and the plane continued to evolve to reflect the "client's" needs -- the USSR. Clearly the P-39 served a valued niche role and the platform evolved into the "hot" P-63 Kingcobra. Again the bulk of production gpoing top the USSR.

The US Air Museum in Ohio has a website with great spec sheets of many US-made WW2 aircraft - check it out. Also - the production totals on the Compare Aircraft website is very useful for production stats. #1 - The Il Sturmavik.

I'd love to hear from anyone with P-39 combat experience ... Chuck Yeager included.

Chairs,

MM
Toronto

MM- Yeager had zero combat experience in P-39 but he did train in it along with the rest of the 357thFG and 354th FG and 363rd FG - but all went into combat in the P-51B.

Second, the interesting anomaly about the Mustang is that it had a steep learning curve from P-51A through P-51D/K. It started out at around 12,000 hours and ~ 58k/ship and finished at 2100 hours and about $53K. The Allison engine was cheaper than the Merlin or the price would have been even lower due to lower GFE costs. The P-47 and P-38 also experinced improvements leading to much lower unit costs than initial production - but nowhere close to P-40/P-39

I suspect NAA pocketed the difference in $$ cost due to much more efficient production techniques and extended purchase.

Glad to have you here.
 

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