No Strategic Bombing?

[wuzak]

Mosquitos BXVIs with 4000lb "cookies" flew in significant numbers in 1945. If they had flown in daylight with fighter escort, they would have been able to fly above the effective altitude of the defending German fighters. If German production and the war had continued, Bf109s and Ta152s with two-stage superchargers were starting to appear. 30,000ft would have ceased to be the relatively safe, happy place for allied aircraft. Where does a 4000lb cookie dropped from 30,000ft land, relative to its intended target.

The question was whether or not the Mosquitos could take over strategic bombing. Clearly, they were not available with 4000lb bombs in 1942-1944. Greg argued that the Mosquitos were not replacements for B17s. I agree.

Strategic bombing of German cities went on for four years. Tactical bombing would last the length of the battle.

The first Mosquito mission to use a 4,000lb bomb was in late Febraury 1944.

I can't confirm if it was a Mk IX or XVI, at the moment. IXs were, IIRC, all produced in 1943. XVIs began production in 1943.

To be sure, there weren't a lot of bomber Mk XVIs at the time, and only 200-odd made at all.

Note that there were conventional 4,000lb bombs that the Mosquito could carry (the 4,000lb MC), but they weren't used, or produced, in large quantities.

 

[Howard Gibson]

The first Mosquito mission to use a 4,000lb bomb was in late Febraury 1944.

I can't confirm if it was a Mk IX or XVI, at the moment. IXs were, IIRC, all produced in 1943. XVIs began production in 1943.

To be sure, there weren't a lot of bomber Mk XVIs at the time, and only 200-odd made at all.

Note that there were conventional 4,000lb bombs that the Mosquito could carry (the 4,000lb MC), but they weren't used, or produced, in large quantities.

A Mosquito BIV had the bulged bomb bay doors for the 4000lb cookie in 1943. About twenty aircraft were converted and they flew night missions in 1943.

Most BXVIs had the bulged doors, and they had two-stage superchargers and pressurized cockpits, so they could fly daylight missions at 28,000 to 30,000ft. These were available in early 1945. As far as I can tell, they actually flew missions at night, at lower altitudes.

The 4000lb cookie was just a big can of explosives.

 

[EwenS]

A Mosquito BIV had the bulged bomb bay doors for the 4000lb cookie in 1943. About twenty aircraft were converted and they flew night missions in 1943.

Most BXVIs had the bulged doors, and they had two-stage superchargers and pressurized cockpits, so they could fly daylight missions at 28,000 to 30,000ft. These were available in early 1945. As far as I can tell, they actually flew missions at night, at lower altitudes.

The 4000lb cookie was just a big can of explosives.

See Sharp & Bowyer's "Mosquito". The idea of modifying a Mosquito IV to carry a 4,000lb bomb was first proposed in April 1943. A modified aircraft, DZ594, first flew in July. 30 sets of conversion parts were in production at that point with three Mk.IV aircraft being converted at Hatfield. But it was undecided whether the other 27 would be fitted to Mk.IV or IX at that stage.

On 9th Oct 1943 a final decision was made about modifying the aircraft. All bomber Mk.IV & IX in service were to be modified to carry a 4,000lb bomb and bomber Mk.IX & XVI in production would be so modified. Production line changes were to be introduced at the end of Oct 1943.

Then the whole project slowed down as A&AEE sought to sort out stability problems with the Mk.IV with heavy bomb loads. As the authors note "They were never fully cured on the Mk.IV. For this reason few Mk.IVs and IXs were modified".

According to the authors the first Mosquitoes to drop 4,000lb bombs operationally were two converted B Mk.IV on 23rd Feb 1944 (the aircraft only having been delivered to 692 squadron on 4th Feb). The target was Dusseldorf.

The Mosquito B.IX only flew operationally with 105 (from July 1943), 139 (from Oct 1943) and 109 (from June 1944) with an odd aircraft in 617. Operations with the Mk.XVI started with 139 on 10/11 Feb 1944 followed by 109, 105 and 692 squadrons in March 1944 and 571 in April.

Early Mk.IX and XVI production was directed towards the PR version. The first PR.IX was delivered to 540 squadron on 29th May 1943 with PR.XVI following in Dec 1943.

The Mosquitos were dropping two kinds of 4,000lb bomb - the HC "Cookie" and the MC weapon. Details can be found here.

https://www.bulletpicker.com/pdf/OP-1665.pdf#page=39

https://www.bulletpicker.com/pdf/OP-1665.pdf#page=34

 

[wuzak]

The Mosquitos were dropping two kinds of 4,000lb bomb - the HC "Cookie" and the MC weapon. Details can be found here.

https://www.bulletpicker.com/pdf/OP-1665.pdf#page=39

https://www.bulletpicker.com/pdf/OP-1665.pdf#page=34

The MC being a GP style bomb.

The HC couldn't be used at low level, so the MC would be used instead.

Was there an incendiary type of bomb with similar dimensions? I seem to recall a 4,000lb IB.

 

[Engineman]

I agree but I will note that the Germans better accuracy relied on radio beams that would not work at England to Germany distances and also relied on good crews and small formations or streams. Also called for electronics that was more than the British could make in 1940 in quantity. British (and American) electronics got a lot better quickly.
If you want pinpoint accuracy the bombers have to fly over the target pretty much in single file, not in formation. Flying formation at night is dangerous and formations spread out.
Flying in long lines really allows the AA guns an easy night's work.

Well, Gee was working in prototype for accurate radio navigation over Germany in mid 1941. The bombing technique was mainly to use Gee for target marking that the rest of the bomber stream then used for visual bombing of the TI's.
Night bomber streams were usually compressed as much as possible. They were not a panacea, but there were advantages in minimised risk routing and force compression to max-out defences. Later, use of EW tactics helped to hide the bombers from the enemy defences.

It is interesting to consider how the RAF early WW2 doctrines of Turret fighters, "the bomber will always get through" and pin-point long range night bombing all fell flat at the first fence. I suggest that British terror-bombing of towns was a desperate measure in early WW2, hinted at politically and purposely obscured by the RAF claims of pin point night bombing. Not until later with Gee, H2S and OBOE was accurate night bombing generally available, but terror-bombing of towns was still done. I suggest that the USAAF possibly adhered to pin point bombing rather than bombing towns, although much collateral damage in towns was caused. USAAF formations usually bombed in formation streams, the size of the formation usually covering the target area. They took terrible losses in the period before long range escort became effective, proving that "the bomber doesn't always get through".

Eng

 

[Geoffrey Sinclair]

A formation of fighter bombers dropping bombs on an oil refinery would be normally classified as a strategic strike in WWII, it is not the bomber but the target which gives the classification as far as the western air forces were concerned. Bomber Command reports dropping 122,532 long tons of bombs on "troops and defences", mostly from April 1944 on, Richard Davis says the 8th Air Force dropped 43,932 sort tons of bombs on "Tactical Targets"

Where does the 4,000 pound idea for strategic bombing come from, as it would rule out almost all USAAF efforts. USAAF HE bombs dropped in ETO 1943 to 1945
6,284,271 Total
158 x 4,500 lb
48,575 x 2,000 lb
564,969 x 1,000 lb
712 x 600 lb
1,645 x 550 lb
3,089,916 x 500 lb
12 x 350 lb
1,055,289 x 250 lb
79 x 160 lb
1,520,209 x 100 lb
2,707 x 40 lb

Bombs weighing more than 500 pounds are around 10% of the total dropped. The 9th Air Force has a lot more weight categories but reports it dropped or jettisoned 22,807 x 2,000 lb and 106,106 x 1,000 lb, there is also the contribution of the USAAF part of 1st Tactical Air Force. The USSBS analysis of all the raids on the oil plants at Leuna, Zeitz and Ludwigshafen, 509,000 USAAF bombs at an average weight of 338 pounds, 264,000 RAF bombs at an average weight of 660 pounds.

In terms of the usual weights of the bombs dropped the Mosquito was matching the USAAF heavies from the start. For Bomber Command in 1944 there were 14,056 Mosquito sorties reporting attacking a target, 5,120 x 4,000 pound bombs were dropped, starting on 23 February 1944. In 1945 it was 8,482 attacking sorties 3,266 x 4,000 pound bombs dropped. Remembering many Mosquito sorties were pathfinder, carrying 250 pound TI, not all of which might be used on a raid.

Lancaster dropped 31,140 x 4,000 pound bombs in 1944 from 84,131 bomb, mine and misc. sorties, 22,081 x 4,000 pound bombs in 1945 from 38,586 bomb, mine and misc. sorties, not even they were carrying a 4,000 pound bomb on every sortie. Mosquito sorties 23 February 1944, 17 sent, 14 attacked primary target Dusseldorf, 1 an alternate, 3 x 4,000 pound HC, 40 x 500 pound GP (3 of thee on alternate target), 3 x 250 pound TI.

Mosquito, long tons, 1942 to 1945, 229.0, 1,546.0, 15,089.1, 9,705.6, total 26,569.7 (29,758 short tons)
USAAF heavies, ETO, short tons, 1942 to 1945, 1,713, 47,452, 446,165, 219,369, total 714,719 (Germany 521,729 tons)

The Mosquito bomber was a victim of its own performance, most Mosquito built as fighters, Bomber Command reports 1 operational Mosquito Bomber squadron as of 1 June 1942, 2 as of 18 December, 3 as of 7 January 1943, 4 as of 30 January 1944, 5 as of 19 March, 6 as of 12 April, 7 as of 6 September, 8 as of 3 October, 9 as of 8 November, 10 as of 29 December, 11 as of 17 February 1945.

As of 22 February 1945 the Bomber units report 14 IV/XX/XXV, 89 IX/XVI, 47 XVI, 81 XX/XXV and 18 XXV on strength, total 249, squadrons with mixtures of marks simply reported a total strength figure.

B.IV production September 1941 to July 1943, B.IX 54 built April to November 1943, B.XVI production from November 1943 with 8 in 1943, 199 in 1944, 193 in 1945. Reconnaissance, 90 PR.IX May to November 1943, PR.XVI, 21 in 1943, 344 in 1944, 70 in 1945.

The allied operation Strangle was an attempt to stop supplies to the German army in Italy south of Rome, despite the relatively limited number of transport options the Germans kept having enough supplies to stay in place. Only when the allied armies attacked did the supply situation help cause a retreat. When it comes to the ETO it took until mid 1944 for the allies to put ground forces into France, even then under the criteria established by General McNair at least one US army in the ETO was experiencing a supply crisis for all but two months of the campaign. On 21st September 1944, First army replies to a request on ammunition consumption by pointing out it has never been supplied at the authorised rate and so the army is not able to determine whether the rate is adequate.

The 9th Air Force reported its P-47 losses were under 1% of credit sorties, the two months it was over 1% were December 1944 and January 1945. 2nd TAF reports 106 losses from 6,889 attacking fighter bomber sorties in June 1944, and 60 losses from 5,261 sorties in July. Or you can note Typhoons did much of the fighter bomber work and 2nd TAF + ADGB had around 316 as of 5 June and so lost around a third the starting strength in June and around half by end July.

Until the mid 1941 Butt report the RAF was busy telling itself the raids were doing well, small forces could do major damage. After the report came the Area Bombing directive.

The Despatch on War Operations gives the Bomber Command accuracy, percentage within 3 miles of target, in 2 month periods in good to moderate weather, at night against German cities excluding Berlin. In good weather accuracy ranged from 25 to 78% in 1942, 25 to 86% in 1943 (average 62%), 68 to 98% in 1944 (average 90%) and 99% in February March 1945. In moderate weather it was 11 to 33% in 1942, 22 to 59% in 1943 (average 44.5%), 55 to 98% in 1944 (average 81%) and 94% in February March 1945. The 1941 and early 1942 results are likely to be biased as only the better crews had bomb cameras, also the peak in 1942 corresponds to mid summer, after GEE had been introduced in March and before the jamming began in early August.

The USAAF raid on Huls (22 June 1943, 224 B-17s despatched plus 11 YB40s, 183 attacked 15 B-17s and 1 YB-40 lost). After the raid the bomb craters were found over an area of 12 square miles, 20% of the bombs dropped hit the 541 acre (0.84 square miles) site. This was done in good weather and was one of the more successful strikes.

Second Schweinfurt raid analysis, from Americas Pursuit of Precision Bombing, MacFarlane. 14 October 1943, 16 Bomb Groups, 229 Bombers, 1st and 3rd wings. 459 1000 lb bombs, 663 500lb, 1751 100 lb (482.2 tons), 3 groups missed the target, 5 had less than 10% of bombs within 500 feet of the target, the 351st with 29% hits were the most accurate, around 10% of the bombs were within 500 feet of the aiming point, 63 direct hits, around 10% of the machinery damaged or destroyed.

There is a detailed series of 8th air force bombing results for the period 1 September 1944 to 31 December 1944, 73 days of operations, 60 to 65,000 sorties. Results, in percentage terms, by bombing method,

A Visual bombing Good to fair visibility
B Visual Bombing poor visibility
C Gee-H
D Micro-H
E H2X 4 to 5/10ths cloud
F H2X 6 to 7/10ths cloud
G H2X 8 to 9/10ths cloud
H H2X 10/10ths cloud

% eff is the percentage of attacks in this period using
the relevant method.

Percentage of bombs dropped within
Method / 1000ft / 0.5mile / 1 mile / 3 miles / 5 miles / %eff
A / 30.0 / 64.3 / 82.4 / 91.5 / 92.2 / 14
B / 9.4 / 34.4 / 53.0 / 85.0 / 91.4 / 10
C / 5.0 / 26.0 / 56.0 / 90.0 / 94.0 / 15
D / 5.0 / 25.7 / 52.4 / 78.2 / 88.5 / 3
E / 4.4 / 22.8 / 48.5 / 89.1 / 96.0 / 3
F / 2.0 / 12.5 / 36.5 / 84.0 / 90.5 / 5
G / 1.0 / 7.3 / 22.5 / 67.4 / 82.0 / 15
H / 0.2 / 11.2 / 5.6 / 39.8 / 58.5 / 35

The USSBS analysis of all the raids on the oil plants at Leuna, Zeitz and Ludwigshafen
8th Air Force, visual bombing 26.8%
8th Air Force part visual/part instrument 12.4%
8th Air Force full instrument 5.4%
Bomber Command at night 15.8%
Weighted average (by bombs dropped) 12.6%

Richard Davis, who examined the records,

"At the highest levels the AAF refused to acknowledge that it engaged in city bombing. However, the records of the U.S. numbered air forces in Europe, in spite of policy discouraging the designating of specific bombing as "city," contains numerous examples of urban strikes. The author takes the AAF at its word. If an AAF, group, wing, air division, or numbered air force report [the author has personally examined all the available mission folders for each air force] designates a raid as a city or town strike, it is counted as such. This method has unearthed many unacknowledged city attacks.

American city bombing entails further caveat. The Eighth Air Force's most comprehensive target summary, prepared in May 1945, does not acknowledge a single instance of city bombing by American aircraft. It systematically changed city raids theretofore carried on Eighth Air Force books to other target categories, usually Industrial Areas (I/A). All raids on Berlin became raids on the "Military and Civilian Government area" (MCG/A). "

Whatever adjective you want to add to bombing it mattered little to the people on the ground. Cities generally had warning and shelter systems, the smaller settlements hit by "tactical" bombing usually had neither and so took more casualties per ton of bombs dropped.

When it comes to the bomber will always get through, ignoring the squadron etc. level attacks, how many raids failed to put some bombs on the target for the day? Part of Baldwin's statement is the bombers would usually take acceptable losses and so would be back tomorrow.

 

[wuzak]

Where does the 4,000 pound idea for strategic bombing come from, as it would rule out almost all USAAF efforts. USAAF HE bombs dropped in ETO 1943 to 1945

It might be the specific comparison between the Mosquito and B-17.

The fact that the Mosquito could carry a 4,000lb bomb internally was impressive (B-17 could carry them under the wing).

The RAF didn't have an equivalent of the US 2,000lb GP bomb.
They did have the older British 1,900lb GP bomb, which had a much lower filling to weight ratio.

4,000lb bombs were also carried by Lancasters, depending on their target. Backed up by 500lb MC, 1,000lb MC or indendiary bombs.

 

[wuzak]

Second Schweinfurt raid analysis, from Americas Pursuit of Precision Bombing, MacFarlane. 14 October 1943, 16 Bomb Groups, 229 Bombers, 1st and 3rd wings. 459 1000 lb bombs, 663 500lb, 1751 100 lb (482.2 tons), 3 groups missed the target, 5 had less than 10% of bombs within 500 feet of the target, the 351st with 29% hits were the most accurate, around 10% of the bombs were within 500 feet of the aiming point, 63 direct hits, around 10% of the machinery damaged or destroyed.

2,873 bombs taken for 63 hits on target?

10% within 500ft = 287 bombs.

I guess the real question is, what type of bombs hit where?

There is a big difference in the damage done by a 1,000lb direct hit and a 100lb direct hit.

Are there any studies of where these bombs were carried in the formation?
For instance, did the bombers in the centre, when looking at the formation width, carry the bigger bombs, and those at the edges carry the smaller ones?

Edit: Which of those bomb groups was the lead group? Was it the 351st?

 

[Shortround6]

Where does the 4,000 pound idea for strategic bombing come from, as it would rule out almost all USAAF efforts.

I believe (could very well be wrong) that the 4000lb pound idea is for a 4000lb bomb load, not a 4000lb bomb, to be the "criteria". Based on the oft quoted Mosquito could carry 4000lbs to Berlin and a B-17 only carried 4000lbs to Berlin.

We all know that the comparison was total BS and was told to a newspaper reporter.
BTW it appears that the first B-17 mission to Berlin was on 3rd March 1944 and had to be aborted due to weather.

https://www.303rdbg.com/missionreports/116.pdf

Bomb load for the 41st Combat Wing (others may differ?)
was 42 x M47 Incendiaries which were about 100lbs each.

Other missions show mixed loads either by different aircraft or by each aircraft carrying different sized bombes, like three 1000lb GP bombs and five 100lb M47 incendiaries.
Mixing sizes/shapes/types of bombs and using a common drop point guarantees one or the other (or both) are going to miss the intended target, question is by how much.

B-17s reached Berlin a few days later and used different bombs with some formations using ten 500lb bombs (so much for the 4000lb load) and others using 42 M47A1 incendiaries.
Here is where the confusion/error comes in. The M-47 bombs could be filled with different incendiary materials and were only notionally 100lb bombs. With one popular filling they only weighed 65lbs and so 42 of them came up to 2730lbs and if you put the two together and average it out you get 3,865lbs, close enough to 4000lbs when trying to impress a female war correspondent.

The B-17s had no hope of holding a 4000lb cookie inside the plane but the Mosquito had no hope of carrying ten 500lbs either and carrying 42 100lb (nominal) incendiary was also an impossibility.

 

[Geoffrey Sinclair]

Bomber Command thinks it dropped 1,239+1,051 (Night + Day) 2,000 pound AP, 25,589+3,051 2,000 pound HC, 37+0 2,000 pound MC, 281+58 2,000 pound M2, 4+0 2,000 pound GP, 7+0 1,900 pound RDX, 1,861+280 1,900 pound GP, unlike the relevant 1,000 and 500 pound bombs the 2,000 pound bombs are not labelled USA.

The night bombers dropped 7 types of 1,000 pound and 6 types of 500 pound bombs, MC types made up 51.3% of 1,000 pound and 34.8% of 500 pound bombs. Day it was 30.3% 1,000 pound MC, 29.7% 500 pound MC. 242,278 long tons HE by day, 510,759.4 by night.

I do not have the mission reports for 2nd Schweinfurt, 14 October 1943, only the summary
Schweinfurt/Kugelfisher, 165.7 short tons HE, average bomb load 4,091.4 pounds
Schweinfurt/VKF 1, 63 short tons HE, 74.1 short tons incendiary, average bomb load 4,495.1 pounds
Schweinfurt/VKF 2, 166.5 short tons HE, 13.5 short tons incendiary, average bomb load 4,186.1 pounds
Which comes to 395.2 short tons HE 87.6 short tons incendiary, total short 482.8 tons Americas Pursuit of Precision Bombing, MacFarlane, is obviously only counting HE.

For the 8th Air Force average bomb load per effective sortie was 5,139.4 pounds per B-17 and 5,321 for the B-24. 15th Air Force 5,276.1 pounds for B-17, 4,462.4 pounds for B-24. Bomber Command reports the average Stirling bomb load was 6,622.2 pounds, Halifax 7,538.6, Lancaster 10,064.5 pounds. The Halifax III carried a higher average bomb load than the mark II and V.

The fact is even the Mosquito mark XVIs did not always carry such a 4,000 pound load, the Bomber Command War Diaries note the last RAF aircraft to bomb Berlin in WWII was a Mosquito XVI on 21 April 1945 and it dropped a load of four 500 pound bombs.

The usual conditions apply to the bomb tonnages mentioned below, they are good put not perfect.

Figures for Mosquito raids where the target is given as Berlin by month, fields are month, number of effective sorties, number lost, bomb tonnage in short tons, average bomb load, that is bomb tonnage divided by effective sorties. Richard Davis figures. The Canadian built Mosquito bombers were restricted to 2,000 pounds internally.

Mar-44 / 52 / 0 / 49 / 1895.38
Apr-44 / 54 / 0 / 65 / 2410.07
May-44 / 108 / 0 / 153 / 2824.89
Jun-44 / 212 / 5 / 376 / 3545.96
Jul-44 / 250 / 4 / 415 / 3316.10
Aug-44 / 240 / 1 / 371 / 3088.40
Sep-44 / 194 / 4 / 294 / 3026.31
Oct-44 / 300 / 4 / 400 / 2668.59
Nov-44 / 251 / 1 / 370 / 2948.59
Dec-44 / 165 / 1 / 227 / 2755.88
Jan-45 / 367 / 1 / 490 / 2672.13
Feb-45 / 815 / 3 / 1,070 / 2625.33
Mar-45 / 1,618 / 7 / 2,077 / 2567.83
Apr-45 / 995 / 4 / 1,426 / 2866.97

Totals / 5,621 / 35 / 7,783 / 2769.26

So the Mosquitoes were carrying 4,000 pound bombs to Berlin, but that was clearly a minority of the sorties. If you assume the loads were either 2,000 or 4,000 pounds then around 40% of the sorties carried the heavier load. The above figures are from 125 nights of raids, minimum average bomb load for a given night was 1,629 pounds (on 15 nights the average was below 2,000 pounds, 10 of these nights were in 1945), maximum nightly average bomb load was 3,689 pounds with 11 nights having an average of 3,400 pounds or greater and all bar 1 of these in June and July 1944, the other the following September.

One explanation for the less than 2,000 pounds average bomb load is siren tours, one or two bombs per city times several cities.

Also, given the usual size of the Mosquito raids, particularly in 1944, an error of 1 aircraft credited with attacking per night would often be able to shift the average 5 to 10%. The average number of Mosquito sorties per raid on Berlin in the March 1944 to April 1945 period is 45.

Average bomb loads US aircraft attacking Berlin, basically the tonnage of bombs credited as dropping on the target divided by the aircraft credited with bombing the target, Richard Davis figures. Note that many to most of these raids had bombers attacking targets other than "Berlin", the usual targets of opportunity or different aiming points, which explains some of the differences between despatched and attacking figures.

Berlin 6 March 1944, 730 bombers despatched, 351 credited with attacking the government area, average bomb load 4,784 pounds. Other formations attacked Potsdam, Spandau and Templehof, all up 19 targets attacked, mostly targets of opportunity.

Berlin 8 March 1944, 623 bombers despatched, 468 credited with attacking Berlin/Erkner VKF, average bomb load 4,535.9 pounds

Berlin on 9 March 1944, 361 B-17s despatched, 332 credited with attacking, average bomb load 4,630 pounds.

Berlin on 22 March 1994, 474 B-17s and 214 B-24s despatched 621 bombers credited with attacking Berlin, average bomb load 4,425 pounds (around 80 bombers attacked other targets, including 32 the Berlin/Basdorf industrial area)

Berlin on 29 April 1944, 446 B-17s and 233 B-24s despatched, 581 bombers credited with attacking Berlin, average bomb load 4,900 pounds.

Berlin on 7 May 1944, 600 B-17s despatched, 525 credited with attacking Berlin, average bomb load 4,810 pounds. The B-24s sent to Osnabruck average bomb load 5,435 pounds.

Berlin on 8 May 1944, 500 B-17s despatched, 384 credited with attacking Berlin, average bomb load 4,765 pounds. The B-24s sent to Brunswick average bomb load 4,790 pounds.

Berlin on 19 May 1944, 588 B-17s despatched, 493 credited with attacking Berlin, average bomb load 4,325 pounds. The B-24s sent to Brunswick average bomb load 5,710 pounds, or around 1,000 pounds more than 11 days earlier

Berlin on 24 May 1944, 616 B-17s despatched, 459 credited with attacking Berlin, average bomb load 4,500 pounds.

Berlin on 21 June 1944, 866 B-17s and 366 B-24s despatched, to many targets, 560 bombers credited with attacking Berlin, average bomb load 4,900 pounds.

Targets in Berlin kept being attacked but generally smaller formations July to November 1944.

Berlin 5 December 1944, 451 B-17 despatched, 174 credited with attacking Berlin/Tegel-Rheinmetal, average bomb load 4,921.8 pounds, 214 credited with attacking Berlin Gas works, average bomb load 4,807.5 pounds,

Berlin on 3 February 1945, 1,093 B-17s despatched, 934 credited with attacking Berlin, average bomb load 4,890 pounds (interestingly the 215 bombers who used H2X to sight their bombs had an average load of around 70 pounds more, which is a warning to treat the figures as a guide, not absolute).

Berlin on 26 February 1945, 840 B-17s and 367 B-24s despatched, to many targets around Berlin, 1,089 bombers credited with attacking 3 targets in Berlin, average bomb load 5,100 pounds. Interestingly the Alexander Platz rail station strike, all B-17, had the highest average of 5,810 pounds, the North rail station strike, all B-24, the lowest at 4,480 pounds. Strike assignments from Freeman, Mighty 8th War Diary. If this is correct presumably this was done to allow the B-24s to fly that little bit higher. This hints at the possibility that, on average, the B-24 carried fewer bombs to Berlin than the B-17, in 1945 anyway.

Berlin on 18 March 1945, 982 B-17s and 347 B-24s despatched, 1,219 bombers credited with attacking. The raid list has 7 entries, for the targets attacked, by between 25 and 498 bombers, bomb load averages from 3,860 to 5,170 pounds, overall average bomb load 5,052 pounds.

Berlin on 28 March 1945, 446 B-17s despatched, 403 credited with attacking, average bomb load 5,155 pounds. By March 1945 many groups were flying with 9 crew, leaving one gunner behind and there was widespread removal of some gun turrets as well. The advantages of air superiority.

Using Richard Davis figures the 8th Air Force dropped 570,338 short tons of HE, 96,774.5 short tons incendiary, 19,983.8 tons fragmentation bombs, total 686,933.3 tons, or 14.1% incendiary overall. For Berlin or Berlin/(target) it was 14,079 HE, 8,978 incendiary, 60.4 fragmentation, or 38.8% incendiary, this would usually reduce average bomb loads.

Bomber Command day bomb raids, 5.6% incendiary, night raids 26.2% overall. Night raids by year, percentage of incendiaries
1940 8.2
1941 12.9
1942 43.6
1943 47.1
1944 18.4 (day 4.3%, overall 13.5%)
1945 19.0 (day 9.2%, overall 15.1%)

Bomber command dropped around 74% of its total wartime tonnage in 1944 and 1945.

 

[wuzak]

Bomber Command thinks it dropped 1,239+1,051 (Night + Day) 2,000 pound AP, 25,589+3,051 2,000 pound HC, 37+0 2,000 pound MC, 281+58 2,000 pound M2, 4+0 2,000 pound GP, 7+0 1,900 pound RDX, 1,861+280 1,900 pound GP, unlike the relevant 1,000 and 500 pound bombs the 2,000 pound bombs are not labelled USA.

I rearranged your data so I could better understand it.
2,000 pound AP - 1,239+1,051 (Night + Day)
2,000 pound HC - 25,589+3,051
2,000 pound MC - 37+0
2,000 pound M2 - 281+58
2,000 pound GP - 4+0
1,900 pound RDX - 7+0
1,900 pound GP - 1,861+280

I have always been under the impression that there was no such thing as a 2,000lb MC bomb.

Is the 2,000lb M2 a variation on the 2,000lb HC?
That was the case for the 4,000lb version.

2,000lb GP would be the American bomb.

The number seems small, but why drop a 2,000lb GP when you have a 4,000lb MC?

 

[GrauGeist]

The number seems small, but why drop a 2,000lb GP when you have a 4,000lb MC?

I would imagine that the target type, location, construction, speed and height of delivery along with other factors, would be the driving force behind the decision.

 

[yulzari]

I would imagine that the target type, location, construction, speed and height of delivery along with other factors, would be the driving force behind the decision.

It can also be the bombs in hand in bomb stores on the station on the day. Ideally they would hold whatever the system needed but day to day reality means that sometimes they had to use whatever was actually available. Something as simple as a minor railway delay due to failed points or signalling, road transport delayed by bad weather or the assorted things that can delay deliveries today as well. "Station X has insufficient 4,000lb MC bombs. Oh well, we will have to load some with x4 500lb GP tonight."

 

[BobB]

2,873 bombs taken for 63 hits on target?

10% within 500ft = 287 bombs.

I guess the real question is, what type of bombs hit where?

There is a big difference in the damage done by a 1,000lb direct hit and a 100lb direct hit.

Are there any studies of where these bombs were carried in the formation?
For instance, did the bombers in the centre, when looking at the formation width, carry the bigger bombs, and those at the edges carry the smaller ones?

Edit: Which of those bomb groups was the lead group? Was it the 351st?

About 61% of the bombs were 100 lb bombs. I wonder if they were intentionally spread wide over the area to help suppress flak and hit "soft" targets associated with the main target. When I was a kid and you could talk to the veterans, I would have never thought to ask questions about bomb selection. One of our airport hangar neighbors had commanded a B-17 squadron and at that level he may have actually had some insight on such practices.

 

[Dimlee]

Bomber Command thinks it dropped 1,239+1,051 (Night + Day) 2,000 pound AP, 25,589+3,051 2,000 pound HC, 37+0 2,000 pound MC, 281+58 2,000 pound M2, 4+0 2,000 pound GP, 7+0 1,900 pound RDX, 1,861+280 1,900 pound GP, unlike the relevant 1,000 and 500 pound bombs the 2,000 pound bombs are not labelled USA.

The night bombers dropped 7 types of 1,000 pound and 6 types of 500 pound bombs, MC types made up 51.3% of 1,000 pound and 34.8% of 500 pound bombs. Day it was 30.3% 1,000 pound MC, 29.7% 500 pound MC. 242,278 long tons HE by day, 510,759.4 by night.

I do not have the mission reports for 2nd Schweinfurt, 14 October 1943, only the summary
Schweinfurt/Kugelfisher, 165.7 short tons HE, average bomb load 4,091.4 pounds
Schweinfurt/VKF 1, 63 short tons HE, 74.1 short tons incendiary, average bomb load 4,495.1 pounds
Schweinfurt/VKF 2, 166.5 short tons HE, 13.5 short tons incendiary, average bomb load 4,186.1 pounds
Which comes to 395.2 short tons HE 87.6 short tons incendiary, total short 482.8 tons Americas Pursuit of Precision Bombing, MacFarlane, is obviously only counting HE.

For the 8th Air Force average bomb load per effective sortie was 5,139.4 pounds per B-17 and 5,321 for the B-24. 15th Air Force 5,276.1 pounds for B-17, 4,462.4 pounds for B-24. Bomber Command reports the average Stirling bomb load was 6,622.2 pounds, Halifax 7,538.6, Lancaster 10,064.5 pounds. The Halifax III carried a higher average bomb load than the mark II and V.

The fact is even the Mosquito mark XVIs did not always carry such a 4,000 pound load, the Bomber Command War Diaries note the last RAF aircraft to bomb Berlin in WWII was a Mosquito XVI on 21 April 1945 and it dropped a load of four 500 pound bombs.

The usual conditions apply to the bomb tonnages mentioned below, they are good put not perfect.

Figures for Mosquito raids where the target is given as Berlin by month, fields are month, number of effective sorties, number lost, bomb tonnage in short tons, average bomb load, that is bomb tonnage divided by effective sorties. Richard Davis figures. The Canadian built Mosquito bombers were restricted to 2,000 pounds internally.

Mar-44 / 52 / 0 / 49 / 1895.38
Apr-44 / 54 / 0 / 65 / 2410.07
May-44 / 108 / 0 / 153 / 2824.89
Jun-44 / 212 / 5 / 376 / 3545.96
Jul-44 / 250 / 4 / 415 / 3316.10
Aug-44 / 240 / 1 / 371 / 3088.40
Sep-44 / 194 / 4 / 294 / 3026.31
Oct-44 / 300 / 4 / 400 / 2668.59
Nov-44 / 251 / 1 / 370 / 2948.59
Dec-44 / 165 / 1 / 227 / 2755.88
Jan-45 / 367 / 1 / 490 / 2672.13
Feb-45 / 815 / 3 / 1,070 / 2625.33
Mar-45 / 1,618 / 7 / 2,077 / 2567.83
Apr-45 / 995 / 4 / 1,426 / 2866.97

Totals / 5,621 / 35 / 7,783 / 2769.26

So the Mosquitoes were carrying 4,000 pound bombs to Berlin, but that was clearly a minority of the sorties. If you assume the loads were either 2,000 or 4,000 pounds then around 40% of the sorties carried the heavier load. The above figures are from 125 nights of raids, minimum average bomb load for a given night was 1,629 pounds (on 15 nights the average was below 2,000 pounds, 10 of these nights were in 1945), maximum nightly average bomb load was 3,689 pounds with 11 nights having an average of 3,400 pounds or greater and all bar 1 of these in June and July 1944, the other the following September.

One explanation for the less than 2,000 pounds average bomb load is siren tours, one or two bombs per city times several cities.

Also, given the usual size of the Mosquito raids, particularly in 1944, an error of 1 aircraft credited with attacking per night would often be able to shift the average 5 to 10%. The average number of Mosquito sorties per raid on Berlin in the March 1944 to April 1945 period is 45.

Average bomb loads US aircraft attacking Berlin, basically the tonnage of bombs credited as dropping on the target divided by the aircraft credited with bombing the target, Richard Davis figures. Note that many to most of these raids had bombers attacking targets other than "Berlin", the usual targets of opportunity or different aiming points, which explains some of the differences between despatched and attacking figures.

Berlin 6 March 1944, 730 bombers despatched, 351 credited with attacking the government area, average bomb load 4,784 pounds. Other formations attacked Potsdam, Spandau and Templehof, all up 19 targets attacked, mostly targets of opportunity.

Berlin 8 March 1944, 623 bombers despatched, 468 credited with attacking Berlin/Erkner VKF, average bomb load 4,535.9 pounds

Berlin on 9 March 1944, 361 B-17s despatched, 332 credited with attacking, average bomb load 4,630 pounds.

Berlin on 22 March 1994, 474 B-17s and 214 B-24s despatched 621 bombers credited with attacking Berlin, average bomb load 4,425 pounds (around 80 bombers attacked other targets, including 32 the Berlin/Basdorf industrial area)

Berlin on 29 April 1944, 446 B-17s and 233 B-24s despatched, 581 bombers credited with attacking Berlin, average bomb load 4,900 pounds.

Berlin on 7 May 1944, 600 B-17s despatched, 525 credited with attacking Berlin, average bomb load 4,810 pounds. The B-24s sent to Osnabruck average bomb load 5,435 pounds.

Berlin on 8 May 1944, 500 B-17s despatched, 384 credited with attacking Berlin, average bomb load 4,765 pounds. The B-24s sent to Brunswick average bomb load 4,790 pounds.

Berlin on 19 May 1944, 588 B-17s despatched, 493 credited with attacking Berlin, average bomb load 4,325 pounds. The B-24s sent to Brunswick average bomb load 5,710 pounds, or around 1,000 pounds more than 11 days earlier

Berlin on 24 May 1944, 616 B-17s despatched, 459 credited with attacking Berlin, average bomb load 4,500 pounds.

Berlin on 21 June 1944, 866 B-17s and 366 B-24s despatched, to many targets, 560 bombers credited with attacking Berlin, average bomb load 4,900 pounds.

Targets in Berlin kept being attacked but generally smaller formations July to November 1944.

Berlin 5 December 1944, 451 B-17 despatched, 174 credited with attacking Berlin/Tegel-Rheinmetal, average bomb load 4,921.8 pounds, 214 credited with attacking Berlin Gas works, average bomb load 4,807.5 pounds,

Berlin on 3 February 1945, 1,093 B-17s despatched, 934 credited with attacking Berlin, average bomb load 4,890 pounds (interestingly the 215 bombers who used H2X to sight their bombs had an average load of around 70 pounds more, which is a warning to treat the figures as a guide, not absolute).

Berlin on 26 February 1945, 840 B-17s and 367 B-24s despatched, to many targets around Berlin, 1,089 bombers credited with attacking 3 targets in Berlin, average bomb load 5,100 pounds. Interestingly the Alexander Platz rail station strike, all B-17, had the highest average of 5,810 pounds, the North rail station strike, all B-24, the lowest at 4,480 pounds. Strike assignments from Freeman, Mighty 8th War Diary. If this is correct presumably this was done to allow the B-24s to fly that little bit higher. This hints at the possibility that, on average, the B-24 carried fewer bombs to Berlin than the B-17, in 1945 anyway.

Berlin on 18 March 1945, 982 B-17s and 347 B-24s despatched, 1,219 bombers credited with attacking. The raid list has 7 entries, for the targets attacked, by between 25 and 498 bombers, bomb load averages from 3,860 to 5,170 pounds, overall average bomb load 5,052 pounds.

Berlin on 28 March 1945, 446 B-17s despatched, 403 credited with attacking, average bomb load 5,155 pounds. By March 1945 many groups were flying with 9 crew, leaving one gunner behind and there was widespread removal of some gun turrets as well. The advantages of air superiority.

Using Richard Davis figures the 8th Air Force dropped 570,338 short tons of HE, 96,774.5 short tons incendiary, 19,983.8 tons fragmentation bombs, total 686,933.3 tons, or 14.1% incendiary overall. For Berlin or Berlin/(target) it was 14,079 HE, 8,978 incendiary, 60.4 fragmentation, or 38.8% incendiary, this would usually reduce average bomb loads.

Bomber Command day bomb raids, 5.6% incendiary, night raids 26.2% overall. Night raids by year, percentage of incendiaries
1940 8.2
1941 12.9
1942 43.6
1943 47.1
1944 18.4 (day 4.3%, overall 13.5%)
1945 19.0 (day 9.2%, overall 15.1%)

Bomber command dropped around 74% of its total wartime tonnage in 1944 and 1945.

Always learning something new from Geoffrey Sinclair's post. Thanks.
Such a low Mosquito's loss ratio is a surprise for me.

 

[wuzak]

About 61% of the bombs were 100 lb bombs. I wonder if they were intentionally spread wide over the area to help suppress flak and hit "soft" targets associated with the main target. When I was a kid and you could talk to the veterans, I would have never thought to ask questions about bomb selection. One of our airport hangar neighbors had commanded a B-17 squadron and at that level he may have actually had some insight on such practices.

Works out to around 18% by weight.

 

[z42]

Always learning something new from Geoffrey Sinclair's post. Thanks.
Such a low Mosquito's loss ratio is a surprise for me.

If you're a German night fighter, why should you spend time chasing down a very fast and nimble target when there are much easier and juicier targets available in the form of the lumbering heavy bombers?

Or as a corollary, had the RAF BC hypothetically switched to an all-Mossie force, losses would have increased as the Germans would have been forced to deal with them. Not as high as the historical heavy bombers faced, but higher than historical Mossie loss rates, would be my guess.

 

[z42]

The historian Phillips O'Brien is an advocate of the position that WWII was decided in the air and at sea rather than on the Eastern front. Described in detail in his book "How the war was won". tl;dr: A review of the book laying out the basic arguments at https://warwick.ac.uk/fac/soc/economics/research/workingpapers/2015/twerp_1077_harrison.pdf

In the original argument, there are I think a couple of interesting variants

1. No strategic bombing, period. Allied air forces are focused on air defense, and tactical bombing. But without a land front to support, what are those tactical bombers supposed to do?
2. Much more limited strategic bombing that historical. Say, avoiding the deliberate targeting of civilians. Of course, the line gets fuzzy. If you're ostensibly trying to hit a railway yard, but your night bombing accuracy is such that at best you can hope to hit the same city as where the railway yard is located, are you engaging in terror bombing?

In both the cases, there would be no vast armadas of four-engined heavy bombers. Where could the resources that were spent building those armadas be utilized instead?

• Devote more resources to the navies. Escort ships like corvettes, escort carriers, long range patrol aircraft could crush the U-boats sooner than historical, maybe? Naval blockade of Norway, preventing Germany from transporting ore along the Norwegian coast?
• More resources to the Med. More naval and aviation resources in the Med could starve out the Axis North Africa campaign sooner, allowing the Sicily and Italian invasions to happen sooner? Americans would probably still not like the British idea of liberating Greece.
• I'm somewhat skeptical about plans to give much more materiel help to the Russians. The Western Allies had no illusions about the nature of the Soviet state. They want to have the Soviets on their side against the Axis, and prevent them from collapsing. But not much more than that. They certainly don't want to see the red flag over Paris.
• D-day in 1943 is most likely too soon.

 

[Dimlee]

No/less strategic bombing allows Germany to deploy resources in... U-boats, blockade running, aviation and other resources to the Med, artillery for the Eastern Front, etc.
Saying that, I like O'Brien's work (including his articles on Substack) and support his view on "how the war was won".

 

[Shortround6]

Bomb loads may have differed a bit from unit to unit.
The bombers carrying three 1000lb bombs were also carrying five 100lb incendiaries according to

https://www.303rdbg.com/missionreports/078.pdf

I don't know what the load out was for the planes carrying 500lb bombs.

The US dropped a lot of incendiaries during the war. Most of the 100lb bombs were incendiaries.