WW2 Strategic Bomber Characteristics

[Shortround6]

However a single squadron would be adequate for attacking a factory

Pure balderdash. A single squadron of what kind of dive bombers using what kind of bombs? Even 500lb bombs were really too light for wrecking a factory. One or two bombs per plane?

what kind of factory?

Dive bombing is not "magic", it takes well trained crews/pilots to achieve those high accuracy results. Low time pilots/crews are not going to be anywhere near as effective.

For your consideration, from Wiki.

"In Schweinfurt the destruction was less severe but still extensive. The two largest factories, Kugelfischer Company and Vereinigte Kugellager Fabrik I, suffered 80 direct hits.[23] 35,000 m² (380,000 square feet) of buildings in the five factories were destroyed, and more than 100,000 m² (1,000,000 square feet) suffered fire damage.[24] All the factories except Kugelfischer had extensive fire damage to machinery when incendiaries ignited the machine oil used in the manufacturing process."

"Albert Speer reported an immediate 34 per cent loss of production"

A squadron of divebombers????

 

[davebender]

Kugelfischer Company and Vereinigte Kugellager Fabrik I, suffered 80 direct hits

What size bombs?

 

[Shortround6]

Some planes carried 5 1000lb bombs, some carried 16 X 250lb incendiaries. That is from just two different squadrons.

 

[davebender]

Me-410A and A1D would probably carry 4 x 250kg / 500lb bombs plus a bunch of fuel.

With 100% accuracy you could accomplish similiar damage with 20 aircraft. 20% dive bomber accuracy is probably more likely, including losses and aborts due to enemy defenses. So you need 100 large dive bombers to accomplish similiar damage.

 

[Vincenzo]

Parsifal the cruise speed in the data card are in TAS not in IAS. However both planes cruise speed are from a data card so this is not a trouble in comparation.
A bomber plane with development start in 38 never see squadron service in 39... The stirling development started early of that of mosquito.

 

[stona]

Me-410A and A1D would probably carry 4 x 250kg / 500lb bombs plus a bunch of fuel.

With 100% accuracy you could accomplish similiar damage with 20 aircraft. 20% dive bomber accuracy is probably more likely, including losses and aborts due to enemy defenses. So you need 100 large dive bombers to accomplish similiar damage.

Are you planning to carry out this raid in daylight? The RAF might have something to say about that.
I don't believe that dive bombing was even possible by night. I don't mean the sort of gentle "swoop" at altitude which some He 177s used but "proper" dive bombing at 70 degrees or more.
Cheers
Steve

 

[davebender]

Some Ju-87s bombed at night. I believe they employed a more shallow angle of attack. With a daytime CEP of 30 meters you can afford some loss of accuracy at night and still hit a factory size target.

 

[stona]

The average factory building was taken as 200' by 200',at least that figure seems to apply to a lot of calculations. Obviously some were very much larger. I doubt you'd hit that at night,assuming of course that you found it in the first place.
Would you not be better off level bombing with radio guidance? At least you'd theoretically be at the correct point in space when you released your bombs.The people of Coventry thought that it worked.
When Bomber Command finally went to Schweinfurt in February 1944,with years of experience bombing at night,some Pathfinders marked and some of the Main Force bombed Nuremberg. They were nearly 60 miles off target.
It is impossible to overestimate,even at this late stage of the war,just how difficult it was to find a target the size of a city,let alone a factory building,at night.
Cheers
Steve

 

[CobberKane]

I think if you are going to compare the merits of fast daylight bomber v heavy daylight bombers the old mossie v fortress argument is probably a good place to start.
The mossie can deliver at least the same payload the same distance (pause here for howls of protest). Please bear in mind that by this I mean that x million dollars worth of Mosquitos can deliver the same bomb load as x million dollars worth of B-17s - you get a lot more mossies for the buck.
The Mosquitos should suffer fewer losses, but I'm not so sure. Certainly they should spend less time over enemy airspace and be much harder to intercept, but if you are going to put e ought Mosquitos into the air to do the same job as a formation of fortresses the would also be easier to detect than the relatively small flights that were actually used
I don't see how the mosquito could have accomplished one of the Fortresses greatest contributions - dragging the LW into the air where escorting fighter could knock them down. The whole point of the mossie was to avoid interception.
I think at the end of the day both the fast unarmed bomber and the heavy strategic bomber were vital. Ther was some overlap in use, but ultimately each could also do things the other couldn't

 

[Shortround6]

HOOOOWWWWWLL

The mossie can deliver at least the same payload the same distance (pause here for howls of protest). Please bear in mind that by this I mean that x million dollars worth of Mosquitos can deliver the same bomb load as x million dollars worth of B-17s - you get a lot more mossies for the buck.

Part of the problem is timing. While the Mossie eventually got to the point that it could haul an equal payload an equal distance, the question is when did that occur?

"The maximum bombload of the first B-17Fs was 9600 pounds, but the range over which such loads could be carried was quite short. On typical missions the load was 4000-5000 pounds over operating ranges of 1400 miles. Beyond these distances, the bombload fell off quite rapidly"

First B-17F came off the line May 30th 1942.
B-17Es had been being produced since Sept 5th 1941, last of 512 produced on May 28th 1942. Normal range 2000 miles with 4000 pounds of bombs. Maximum bomb load (for the E) was 26 100-pound bombs, or 16 300-pound bombs, or 12 500-pound bombs, or 8 1000-pound bombs, or 4 2000-pound bombs. The 9600lb bomb load was six 1600lb AP bombs which was a rather specialized load.
The US had arranged for mass production of the B-17 on a large scale in 1941.
"the Army Air Forces encouraged the organization of a manufacturing pool in which Boeing, the Vega division of Lockheed, and Douglas would all participate in the building of the B-17E. The pool became rather irreverently known as "B.V.D", after the trade name for a popular line of underwear which had become a household name in America. Production of the B-17E at the main Boeing plant at Seattle was to be augmented by another Boeing plant at Wichita, Kansas. The Douglas plant at Santa Monica, California was to be joined in B-17E production by a new Douglas plant at Long Beach, California which had been built specifically for Fortress production. However, before the plan could reach fruition, the B-17F was ready for production, and the F was the first version to built jointly by all three companies. No B-17Es were actually built by either Lockheed or Douglas."
This also included getting Studebaker to build Cyclone engines, First engines came out the door in Feb 1942 and Studebaker went on to build 6,091 engines in 1942, 23,066 in 1943 and 27,920 in 1944 (roughly 3/4s of all Cyclones made in 1944).

Interrupting programs of this size and trying to switch both engines and air frames is not easy and creates some rather large production holes.

 

[wuzak]

I don't see how the mosquito could have accomplished one of the Fortresses greatest contributions - dragging the LW into the air where escorting fighter could knock them down. The whole point of the mossie was to avoid interception.

I disagree. If Mosquitoes were used in sufficient numbers and if Mosquitoes were doing equivalent damage the Luftwaffe would be forced to respond. And that means sending fighters.

Even so, close escort of Mosquitoes was problematic. The escorts and the bombers would both be forced to fly at compromised speeds, causing a reduction in range for both.

Instead the escort fighters would be used more independently. And if the Luftwaffe didn't rise to meet the Mosquitoes the escorts would be free to hunt the fighters at their own airbases.

 

[wuzak]

HOOOOWWWWWLL



Part of the problem is timing. While the Mossie eventually got to the point that it could haul an equal payload an equal distance, the question is when did that occur?

"The maximum bombload of the first B-17Fs was 9600 pounds, but the range over which such loads could be carried was quite short. On typical missions the load was 4000-5000 pounds over operating ranges of 1400 miles. Beyond these distances, the bombload fell off quite rapidly"

First B-17F came off the line May 30th 1942.
B-17Es had been being produced since Sept 5th 1941, last of 512 produced on May 28th 1942. Normal range 2000 miles with 4000 pounds of bombs. Maximum bomb load (for the E) was 26 100-pound bombs, or 16 300-pound bombs, or 12 500-pound bombs, or 8 1000-pound bombs, or 4 2000-pound bombs. The 9600lb bomb load was six 1600lb AP bombs which was a rather specialized load.
The US had arranged for mass production of the B-17 on a large scale in 1941.
"the Army Air Forces encouraged the organization of a manufacturing pool in which Boeing, the Vega division of Lockheed, and Douglas would all participate in the building of the B-17E. The pool became rather irreverently known as "B.V.D", after the trade name for a popular line of underwear which had become a household name in America. Production of the B-17E at the main Boeing plant at Seattle was to be augmented by another Boeing plant at Wichita, Kansas. The Douglas plant at Santa Monica, California was to be joined in B-17E production by a new Douglas plant at Long Beach, California which had been built specifically for Fortress production. However, before the plan could reach fruition, the B-17F was ready for production, and the F was the first version to built jointly by all three companies. No B-17Es were actually built by either Lockheed or Douglas."
This also included getting Studebaker to build Cyclone engines, First engines came out the door in Feb 1942 and Studebaker went on to build 6,091 engines in 1942, 23,066 in 1943 and 27,920 in 1944 (roughly 3/4s of all Cyclones made in 1944).

Interrupting programs of this size and trying to switch both engines and air frames is not easy and creates some rather large production holes.

My understanding is that the B-17 could only carry 2 x 2000lb bombs internally. It could carry additional bombs to that, of course.

The USAAF's most popular bombs were:
1. 500lb GP 3.7m dropped
2. 100lb GP 2.1m
3. 100lb Incendiary 1.7m
4. 250lb GP 1.3m
5. 120lb Fragmentation Cluster 1.0m
6. 1000lb GP 750k
7. 440lb Fragmentation Cluster 360k
8. 260lb Individual Fragmentation 320k
9. 228lb Incendiary Cluster 255k
10. 69lb Fragmentation Cluster (Parachute) 100k
11. 2000lb GP 65k
12. 500lb Incendiary 64k
13. 500lb SAP 31k
14. 1000lb SAP 23k
34. 4000lb HE 1.2k
35. 1600lb AP 1.1k

Apart from the 2000lb and 4000lb bombs there the Mosquito could probably carry the RAF equivalent. And after mid '43 they had the capability to haul the 4000lb bomb. The RAF didn't have a 2000lb MC bomb, but did have a 1900lb GP bomb - which was low in charge to weight ratio.

To my mind the question is not how many bombs can an aircraft haul over a distance, but to how many the aircraft can put on target.

 

[Milosh]

To my mind the question is not how many bombs can an aircraft haul over a distance, but to how many the aircraft can put on target.

If the B-17 is shot down then no bombs on target. With 2 Mosquitoes with a total of the B-17s bomb load, if one is shot down, at least the other Mosquito puts some bombs on target.

Army Air Forces Statistical Digest, World War II

Table 137 -- Number of Bombs Dropped Overseas, By Type of Bomb: 1943 to 1945
Army Air Forces in World War II

 

[wuzak]

I agree.

Objective is to destroy enemy industrial infrastructure. Which requires hitting factory size objects with bombs of 500 to 2,000 lbs.

4000lb bombs would be better again.
So, probably, would 8000lb bombs, but precious few aircraft in WW2 could do such a thing.

It is also the type of bomb used. I'm not sure if the British thin case "High Capacity" bombs were suitable for industrial targets. I think that the "Medium Capacity" bombs were better suited for such targets. These are equivalent to US GP bombs (roughly 50% charge to weight).

The problem with bigger bombs is that you carry less of them. And accuracy becomes even more vital.

 

[Shortround6]

The Mosquito was a remarkable plane and with 20/20 hindsight may have been a better choice.

However when the choices were being made the Mosquito was unproven and in large part it's future performance unknown.

"W4050 continued to be used for long and varied testing programs, being essentially the experimental "workhorse" for the Mosquito family.[43] In late October 1941, it was taken back to the factory to be fitted with Merlin 61s, the first production Merlins fitted with a two-speed, two-stage supercharger. The first flight with the new engines was on 20 June 1942". At this point you have 3 factories already tooled up for the B-17F with aircraft on the production lines if not already out the door and a 4th factory in the process of being built/tooled up. First bomber Mosquito squadron becomes operational the month before.

"In April 1943, a decision was made to convert a B Mk IV to carry a 4,000 lb (1,812 kg), thin cased High explosive bomb (nicknamed "Cookie").

"The B-17G was introduced onto the Fortress production line in July of 1943"

BTW, May 1943 sees the Memphis Belle return from it's 25th Mission.

With the Benefit of Hindsight perhaps the Mosquito might have been the better choice but the decision would have had to have been made around the fall/winter of 1940.

 

[Aozora]

These are the British bombs, up to 4,000 lbs used during the war: unfortunately the table doesn't specify whether the numbers and weights dropped are applicable only to the Mosquito - according to the page from the Dambusters Owner's Manual (below), 68,000 4,000 lb "Cookies" were dropped during the war. I just don't know whether Mosquitoes managed to drop over 8,000 of them...

(From Simons; Mosquito The Original Multi-Role Combat Aircraft Pen and Sword 2011, page 168 ).

These are the the larger, more specialised bombs used:

 

[stona]

The Mosquitos should suffer fewer losses, but I'm not so sure. Certainly they should spend less time over enemy airspace and be much harder to intercept, but if you are going to put e ought Mosquitos into the air to do the same job as a formation of fortresses the would also be easier to detect than the relatively small flights that were actually used

Exactly so. One of the reasons that the low level penetrations that I described earlier as strategic "pin pricks" were sometimes successful is because they involved few aircraft,were infrequent and thereby were unexpected. They had the element of surprise.Most mornings the Luftwaffe command didn't wake up expecting to have to intercept a low level raid by a few high speed intruders!
To imagine that large formations of Mosquitos could carry out a strategic bombing campaign flying just about every day the weather allowed with the same level of losses as the special raids doesn't seem plausible at all.
Cheers
Steve

 

[mhuxt]

I just don't know whether Mosquitoes managed to drop over 8,000 of them...

Hi Aozora,

Appendix 24 in Sharp Bowyer's "Mosquito" has this:

4,000 lb bombs dropped by Mosquitoes, 1943 - 1945:
HC: 776
M2: 7,469
MC: 141
Inc: 8

Looks like more than 8,000 to me...

 

[wuzak]

These are the British bombs, up to 4,000 lbs used during the war: unfortunately the table doesn't specify whether the numbers and weights dropped are applicable only to the Mosquito - according to the page from the Dambusters Owner's Manual (below), 68,000 4,000 lb "Cookies" were dropped during the war. I just don't know whether Mosquitoes managed to drop over 8,000 of them...
View attachment 222197
(From Simons; Mosquito The Original Multi-Role Combat Aircraft Pen and Sword 2011, page 168 ).

These are the the larger, more specialised bombs used:

View attachment 222198

I don't think the numbers dropped are correct in the first table. For one, the number of 4000lb HC bombs dropped doesn't match the amount in the second excerpt.

Also, 627 Squadron dropped 8 1000lb MC bombs and 4 1000lb GP bombs in the raid on the Gestapo Headquarters in Oslo on 31/12/43.


4000lb High Capacity Bomb has 93,000 4000lb HC bombs dropped during WW2.

256,000+ 1000lb bombs dropped from 1943-1945 1000lb Medium Capacity Bomb

686,000 1000lb GP bombs 1000lb General Purpose Bomb

1.7m 500lb GP or MC bombs dropped 50lb, 120lb, 250lb, 500lb General Purpose Bombs

Interestingly their table shows no use of the 250lb GP bomb in 1943 or after, and only a handful of the 120lb GP bomb.

 

[wuzak]

Hi Aozora,

Appendix 24 in Sharp Bowyer's "Mosquito" has this:

4,000 lb bombs dropped by Mosquitoes, 1943 - 1945:
HC: 776
M2: 7,469
MC: 141
Inc: 8

Looks like more than 8,000 to me...

So the numbers only apply to the bombs dropped by Mosquitoes?