WW2 Strategic Bomber Characteristics

[tomo pauk]

I was assuming that the targets were defended.

Steve

No problems with the assumption, I was thinking the same. Mosquitoes were attacking defended targets from altitudes far under the 20000 ft, hence my comment.

You could look at an A-26 for an idea of the performance to be had from a twin engine bomber using R-2800s ( at least without turbos), granted it was not unarmed but it only carried a three man crew (with glass nose). It was the first twin engine bomber to use a laminar flow wing, it was the first bomber to use double slotted flaps.

It had a Radius of about 790-860 N miles (908-909 S miles) at about 10,000ft with 4000lb of bombs at about 230mpheconomical cruise speed. max speed of 372mph at 10,000ft may have been using 2370 hp per engine using WER and water injection.

It's wing was about 20% bigger than a Mosquito's wing but take-off weight could go to 37-40,000lbs.

Yes you could ditch the turrets and the fixed guns and gain 1500-3000lb of bombs/fuel but you can't make the plane much smaller and still hold the extra fuel/bombs. You could add two stage superchargers or turbos for more altitude capability (Ceiling at "combat weight ( 29-32,000lbs) at max power with 500ft per minute in hand was about 22000-23400ft) but that takes volume and some of the saved weight from the guns.

Thanks for pointing me to the A-26. Laminar-flow wings were not what one would expect in the early war plane, some 'classic' thin wings can come in play, when one wants high speed. Such a plane, but with a V-12 would come close to A-26 drag.

Bombing Berlin with a big twin with 5000lb of bombs (same load as a B-17) certainly seems possible but the speed advantage may be a cruise of 230-250mph instead of the B-17s 180mph.

Think we should not expect from a twin-engined plane to beat a 4-engined plane in his game (bombload vs. range. vs. speed).

Please remember that the a lot of the Mosquito's performance came from the 2 stage engines and was only shown in 1943. Decisions as to which types of bombers to use if you want them in large numbers in 1943 had to be made in 1941 at the latest.

Agreed about the need to allocate crucial things in a timely manner.
No doubt that 2-stage Merlin gave the Mosquito another performance boost. The single stage versions were also speedy birds, eg. Mk.IV (bomber) maxing out at some 360-370 mph, cruising at 330-340 mph, and going even faster with revised exhaust system (circa +15 mph).

Granted there was a bit of messing around with the program and things were not pushed as fast as they could have been been but the first 3 A-26 prototypes were ordered in in mid 1941, well before Pearl Harbor. First combat use was in late 1944. Maybe you could speed up things so your "fast bomber" shows up in the Spring of 1944?

USAF have had the twin R-2800 in use much earlier, flying sorties in Midway (B-26). They also have had the attack bomber with thin wings (A-20). USA also has had in production planes with Fowler flaps (by Lockheed). So there were no breakthroughs needed for a really fast bomber made in USA, in 1942.
USA was well capable to make a fast 4-engined bomber with R-2800, for 1942, and/or such a plane with turbos, for 1943.

re. A-26: we can note that plane was not using the last say about R-2800, it was using the single stage, B series engines. One can only wonder how fast it would be with 2-stager, or with turbo. +ADI?

 

[stona]

No problems with the assumption, I was thinking the same. Mosquitoes were attacking defended targets from altitudes far under the 20000 ft, hence my comment.

You can't compare the tactics used by handfuls of aircraft on special missions with those they could have used to carry out a strategic bombing campaign against some of the most heavily defended targets in the world at that time.

Altitude as well as speed was part of their defence.

I don't know what flak was around Amiens or Copenhagen,but it was irrelevant compared to any target in the Ruhr.

Bennet rejected the concept of low level marking for pathfinder Mosquitos,originally proposed by Chesire. It did happen when Harris transferred 627 squadron to 5 Group. Cochrane was a proponent of Chesire's scheme.


Cheers

Steve

 

[tomo pauk]

It's my understanding that Mosquito bomber and pathfinder sorties, undertaken by night, suffered far less casualties per tonnage that hit home than other bombers. If someone can confirm, or disprove this, it would be nice to post it.

Smallish bombers can perform some things better than big ones. Eg. they can cruise at 25000 ft, make shallow fast dive to 15000 ft, level out, drop bombs and climb back, then head home. I agree that, if the tonnage dropped (not tonnage that hit home) is the game breaker, one needs twice (maybe more?) twin-engined planes vs. 4 engined ones, so here such an unarmed bomber comes to play.

 

[Vincenzo]

i think you need 5 mosquito for the same load of 1 lancaster and probably lancaster has advantage in range

 

[Shortround6]

Thanks for pointing me to the A-26. Laminar-flow wings were not what one would expect in the early war plane, some 'classic' thin wings can come in play, when one wants high speed. Such a plane, but with a V-12 would come close to A-26 drag.

Just pointing it out as a benchmark, you are unlikely to much better.

USAF have had the twin R-2800 in use much earlier, flying sorties in Midway (B-26). They also have had the attack bomber with thin wings (A-20). USA also has had in production planes with Fowler flaps (by Lockheed). So there were no breakthroughs needed for a really fast bomber made in USA, in 1942.
USA was well capable to make a fast 4-engined bomber with R-2800, for 1942, and/or such a plane with turbos, for 1943.

re. A-26: we can note that plane was not using the last say about R-2800, it was using the single stage, B series engines. One can only wonder how fast it would be with 2-stager, or with turbo. +ADI?

It depends on how fast you want to go and how far. The A-20 carried 400 US gallons in the wing. The A-26 carried 400 US gallons in each wing.

Original B-26B had a number of combinations such as 962 US gallons in the wing plus two 250 US gallon tanks in the bomb bay giving a range of nearly 2000 miles in 9.7 hours while carrying a 1500lb bomb load. With 962 gallons and at max cruise 4000lb could be carried 550 miles in two hours. Armament was two .50s in the power turret, two .50s in the tail and ONE .30 OR .50 in the nose and one .30 OR .50 out the bottom. Early B-26s with a top speed of 315mph had a the twin .50 turret, a .30 out the nose and another out the bottom and singe .50 in the tail.

If you want R-2800s you are going to have to feed them

You may want to look at the F7F Tigercat fuel capacity (375-455 US gallons internal (two seater-single seater)) cruise speeds ( 177-235mph) and ranges (810-1200 miles). You aren't going to get much smaller than an F7F with two R-2800s and it doesn't have a bomb bay.

 

[stona]

Bomber Command Mosquitos flew 39,795 sorties for 260 losses to all causes. A measley 0.65%

The figure is 2.20% for the Lancaster and 2.28% for the Halifax.

It makes the "what aircraft would you want to fly in WW2 question a no brainer

Cheers

Steve

 

[Vincenzo]

yes but also Lancaster miss 1 each 182 tons of bomb dropped, Mosquito miss 1 each 106 tons of bomb dropped
Mosquito scrapped plane 56% of operational missing (so total loss 1%, 1 each 68 ton of bombs)
Lancaster scrapped plane 15% of operational missing (so total loss 2.45%, 1 each 159 ton of bombs)

Lancaster average bomb load in bombing 4.49 tons
Mosquito average bomb load in bombing 1.08



source lancaster-archive.com, calculations mine

 

[stona]

yes but also Lancaster miss 1 each 182 tons of bomb dropped, Mosquito miss 1 each 106 tons of bomb dropped
Mosquito scrapped plane 56% of operational missing (so total loss 1%, 1 each 68 ton of bombs)
Lancaster scrapped plane 15% of operational missing (so total loss 2.45%, 1 each 159 ton of bombs)

Lancaster average bomb load in bombing 4.49 tons
Mosquito average bomb load in bombing 1.08

source lancaster-archive.com, calculations mine

Statistics! Factor in the cost of a sortie for example. Or the cost of the aircraft. A Mosquito cost about 1/3 the price of a lancaster

At least with percentage loss by sorties we are comparing apples with apples.

Steve

 

[davebender]

22 Ju-288 airframes built.
289 Jumo 222 engines built.
.....Enough to provide historical performance data.

Very fast. Carried a decent size internal bomb load. Less expensive then 4 engine bombers. If I were going to procure a WWII era strategic bomber it would look a lot like the Ju-288.
.....U.S. version powered by two R-2800 radial engines.
.....British version powered by two Napier Sabre engines. Or else have Packard build R-2800 engines for RAF Bomber Command.

 

[tomo pauk]

i think you need 5 mosquito for the same load of 1 lancaster and probably lancaster has advantage in range

It was 4:1?

Just pointing it out as a benchmark, you are unlikely to much better.

It depends on how fast you want to go and how far. The A-20 carried 400 US gallons in the wing. The A-26 carried 400 US gallons in each wing.

Was the A-20 carrying 400 gals in wings because of it was to be used in 'attack' role, ie. for the tasks close to the airbase?
Looking at the diagram, the space in wings does not seem like a space well used, ie. no fuel tanks aft main spar, while the outboard fuel tank is rather short, and no fuel (worth speak about) is in nacelles. Late P-38, in a smaller wing, was carrying 10 gals more. Further, no fuel was carried between inboard tanks. So there was plenty of space available, later versions carrying 144 USG in upper bomb bay, and later even more, 326 USG, as one can see in the tables kindly provided by Neil Stirling. With 726 USG it was able to carry 2000 lbs, range being 1570 HP on 2 x 1600 HP.
If we want to be strict, the A-26 carried only 100 gals in each wing, along with 300 in each nacelle. Plus the permanent fuel tank above beomb bay, plus wing drop tanks (being a more flexible thing than under-belly tank available for A-20).

Original B-26B had a number of combinations such as 962 US gallons in the wing plus two 250 US gallon tanks in the bomb bay giving a range of nearly 2000 miles in 9.7 hours while carrying a 1500lb bomb load. With 962 gallons and at max cruise 4000lb could be carried 550 miles in two hours. Armament was two .50s in the power turret, two .50s in the tail and ONE .30 OR .50 in the nose and one .30 OR .50 out the bottom. Early B-26s with a top speed of 315mph had a the twin .50 turret, a .30 out the nose and another out the bottom and singe .50 in the tail.

Thanks for the numbers.
Early B-26 have had it's issues. The wing was tick, but of small area (for weight carried), and with flaps being only inboard. Net result was a plane that neither gave good turn of speed, nor it was easy to fly on lower speeds.

If you want R-2800s you are going to have to feed them
You may want to look at the F7F Tigercat fuel capacity (375-455 US gallons internal (two seater-single seater)) cruise speeds ( 177-235mph) and ranges (810-1200 miles). You aren't going to get much smaller than an F7F with two R-2800s and it doesn't have a bomb bay.

Yes, indeed. A plane sized between A-20 and A-26, that could carry 850 gals, plus a worthwhile bomb load to a good distance. Maybe you could check the values for the F7F, the cruise speeds for the Boston IV were 210-270 mph (most economic and max power on lean mixture).

added: fuel systems of A-20 A-26

 

[Shortround6]

Getting back to the original question:

WW2 Strategic Bomber Characteristics:

The most important one wasn't listed.

The most important is enough range to hit a strategic target. Required range changed with theater and as front lines (possible bases) shifted. Also as enemies changed or enemies changed location of strategic targets. Like Russian transfer of industry to the Urals or beyond.

Once you have range ( and the navigational ability to find the target) then you can worry about bomb load (target effect) vs survivability ( losses low enough to sustain campaign). Speed, Defensive armament, High operating altitude, Armour all come under survivability.

 

[Vincenzo]

It was 4:1?

from my post 10th:
Mosquito XVI range most economical cruise (245 mph) with 2,000 lbs of internal bombs 1,795 miles
Manchester as above (185 mph) with 8,100 lbs of internal bombs 1,630 miles

so need 4 Mosquito for a Manchester with range advantage for Mosquito

my post 24th: need 5 Mosquito for 1 Lancaster with range advantage for Lancaster

my estimation on Lancaster capability from Manchester data

 

[tomo pauk]

Good points, people.
Think we can agree that, in order to reach a distant target with meaningful bomb load and survivability, the 4-engined plane is needed.

 

[davebender]

With WWII era bomb sights high operating altitude almost guarantees poor accuracy. If you aren't going to hit the target then why bomb at all?

 

[Shortround6]

Well, you could always dive bomb..........

We know how that worked out.........

great if the defenders don't have any anti-aircraft guns, barrage balloons, smoke generators or defending aircraft.


If they do.........

 

[parsifal]

Good points, people.
Think we can agree that, in order to reach a distant target with meaningful bomb load and survivability, the 4-engined plane is needed.

Absolutely not. Mosquitoes could deliver a 1500 lb bomb load all the way to Berlin, bomb the target twice, in the same time it took a Stirling to deliver a 3000 lb load, buit suffer 4 to 5 times the loss rates. Mosquitoes were the designated precision bombing aircraft and selected as Pathfinders for the bombing force for a reason.

Dont be fooled by the LW ra ra boys. They want to discount the best wepons in the allied arsenal every time

 

[Aozora]

What types of bombs are best for strategic campaigns?

A large number of small bombs, or a small number of large bombs? Or intermediate numbers of medium sized bombs?

I guess that all depends on the type of target.
What about for oil refineries/synthetic oil plants?
Is it the same for industrial targets like airframe or engine manufacturers?

What was needed was an airframe capable of carrying a combination of loads so that bomb types and sizes could be adapted to the target requirements: for example, there are plenty of instances where factory buildings were demolished by bombs of up to 1,000lbs, but the machine tools and other vital equipment remained intact, enabling a new plant to be set up very quickly.

 

[Glider]

What was needed was an airframe capable of carrying a combination of loads so that bomb types and sizes could be adapted to the target requirements: for example, there are plenty of instances where factory buildings were demolished by bombs of up to 1,000lbs, but the machine tools and other vital equipment remained intact, enabling a new plant to be set up very quickly.

That more or less rules out the b17/B24 (according to some)

 

[mhuxt]

Absolutely not. Mosquitoes could deliver a 1500 lb bomb load all the way to Berlin, bomb the target twice, in the same time it took a Stirling to deliver a 3000 lb load, buit suffer 4 to 5 times the loss rates. Mosquitoes were the designated precision bombing aircraft and selected as Pathfinders for the bombing force for a reason.

Dont be fooled by the LW ra ra boys. They want to discount the best wepons in the allied arsenal every time

Actually, Mosquitos were taking 4,000 lb loads to Berlin, in the shape of "cookies", also, apparently, referred to as "dangerous dustbins." And yes, they could do it twice in one night, though I think not as frequently as may be thought.

 

[Vincenzo]

mhust what is the source of Mosquito with 4,000 lbs on Berlin?

parsifal Stirling is a older plane.
Lancaster was the newest 4 engined (and however go in mission before of Mosquito bomber), and the mosquito has not twice the speed (probably 200 vs 245 in most economical and 250 vs 320 in max weak)