Were long range heavy bombers effective?

[Oldman731]

IF the RAF had been completely suppressed to the point that the Luftwaffe had total air dominance over southern England, the RN would not have had the opportunity to interfere with any German channel crossing. Moving 1940-era warships with their very limited AA capabilities into range of Stukas and Ju 88's would have been suicide. Just ask any of the crew of HMS Prince of Wales or HMS Repulse...

Stukas and Ju88s were not good at night dive-bombing. The invasion force could not have started in daylight and landed in daylight.

- oldman

[Zimme83]

The problems with this are manyfold:

US heavy bomber combat boxes were ideally about 2000 ft across for a 36 plane formation, and about 2500 ft across for a 54 plane formation. Mutual defense doctrine required these large formations in occupied airspace. They were often larger in practice, particularly when faced with heavy flak or high wind conditions. So, if you want large bomber formations, you're going to have to accept lower accuracy;

Major industrial complexes and vital industries weren't dispersed or out of reach - at least not in Germany or Japan. They were typically located in and around the outskirts of major cities, quite often with high-density worker housing in the immediate areas. The same story goes for railway junctions, except that many of these were located in the residential hearts of major cities. Same thing for many airfields;

Precision really was not an option. 1944 medium altitude (15,000 ft) daylight missions had an average CEP of 825 ft to 1175 ft. At average altitudes of 23,000 to 27,000 ft, CEP for 1944 average just under 3000 ft. Blind-boming and missions with heavy cloud had CEPs of better than 5200 ft. The average 8th AF radial bombing error on German oil industry targets in 1944-1945 was 2.5 miles. Just 2.2% of bombs dropped fell within the boundaries of production facilities.

Here are the USSBS figures for September 1944 to December 1944 for "visual bombing with "good to fair visibility":

Percentage of bombs dropped within
     1000ft  0.5mile  1 mile  3 miles  5 miles %eff
A     30.0      64.3      82.4    91.5      92.2     14

If you want to bomb nothing but military targets on the western front between 1942 and June 1944, then you're going to be fighting a bomber war similar to the one the RAF experienced in 1939-1940. You'll face a limited number of targets, of minimal to moderate strategic value, that are comparatively well protected. Due to the limited target choice, the Luftwaffe will generally know where you're attacking, and they'll be able to concentrate resources more effectively. Not a war I want to fight.

There was plenty the USAAF could do to improve its accuracy. From an old discussion on this topic, on another board, I made this list:

Use larger bombs,
Bomb from lower altitudes, 11,000-15,000 ft would have been necessary for sub 750ft CEPs
Bomb in smaller formations,
Increase intervals between bomb groups to reduce target occlusion
Reduce the width of combat boxes,
Switch to an all B-17 force, as they were more accurate bombing platforms than B-24
Increase the level of training for crews, particularly for pilots, bombardiers and navigatiors
Improve meteorological forecasting, particularly wind directions at targets
Never visually bomb through anything more than four tenths cloud,
Abandon blind bombing techniques
Introduce pathfinder aircraft
Reduce or eliminate use of fragmentation bombs and incendiaries

The 8th AF determined the four most significant factors in terms of accuracy were:
The cloud/visibility conditions above the target. This could affect accuracy by a factor of 10.
The number of bomb groups involved in the raid. A raid of three bomb groups was up to 40% more accurate than a raid of 10 or more groups
Bombing altitude.
The amount of flak over a target. Particularly heavy flak could halve bombing accuracy.

U did not get the point, i didnt said "dont hit civilian areas under any circumstances" If we put moral arguments aside, collateral damage would have been inevidable even when only concentrating on specific targets. But thats not the same as targeting residential areas. Dresden is an example of the latter.

[Jabberwock]

If you want to eliminate residential bombing, you have to force Bomber Command to bomb in daylight and force the 8th AF to radically revise its target lists.
This essentially means changing the entire character of the ETO air war between late 1940 and the beginning of 1945.

I'm not advocating for area bombing/and or de-housing. It was a dreadful policy that resulted in way too many casualties on both sides.

I am arguing that a combination of circumstances - battle experience and history, doctrine, effectiveness evaluations, the psychology of the commanders and the limitations of tactics and technology of the period - essentially forced de-housing and area bombing on Bomber Command, and resulted in the 8th AF adopting techniques that were precision bombing in name, but area bombing in practical effect (at least for missions involving anything more than 4/10ths cloud cover).

The heavy bomber forces were analogous to a steam roller - it doesn't matter how precisely its driven, using them is going to result in a lot of things getting flattened.

But, and its a big but, if you find you are in the circumstances of the US and the UK in 1941/1942, are you going to sideline completely? Because of the accuracy inherent in WW2 bombing, the results of a 10-group 8th AF raid on the oil and port facilites in, say, Bremen in 1944, are almost indistinguishable from a Bomber Command raid on the centre of the city.

[Volron]

IF the RAF had been completely suppressed to the point that the Luftwaffe had total air dominance over southern England, the RN would not have had the opportunity to interfere with any German channel crossing. Moving 1940-era warships with their very limited AA capabilities into range of Stukas and Ju 88's would have been suicide. Just ask any of the crew of HMS Prince of Wales or HMS Repulse...

The Prince of Wales and Repulse were sunk by the Japanese, who were better trained in terms of attacking ships than the Germans.  Still, the RN would have pushed forward against the invasion force, regardless of Luftwaffe air superiority.  The other thing to note is that the RN also had something the Germans didn't, carriers.  So there would still be air cover for the RN, even if it was meager.

[PR3D4TOR]

Stukas and Ju88s were not good at night dive-bombing. The invasion force could not have started in daylight and landed in daylight. With the RAF neutralized Luftwaffe bomber could have operated as far as Ireland. The RN ships would have had to run the gauntlet up the Channel.

- oldman

There is no way the RN could have started outside Luftwaffe range and made it all the way up the Channel in one night.

[PR3D4TOR]

The Prince of Wales and Repulse were sunk by the Japanese, who were better trained in terms of attacking ships than the Germans.  Still, the RN would have pushed forward against the invasion force, regardless of Luftwaffe air superiority.  The other thing to note is that the RN also had something the Germans didn't, carriers.  So there would still be air cover for the RN, even if it was meager.

In 1940 the RN did not have any carrier fighters available.

[PR3D4TOR]

Oh and after the Channel Battle the Luftwaffe had plenty of experience in attacking ships. They sank more than 40 ships including four RN destroyers.

[Squire]

Use larger bombs,

How does that increase accuracy in any significant way? in any case various types were tried by the RAF and none increased bombing accuracy overall by any great degree.

Bomb from lower altitudes, 11,000-15,000 ft would have been necessary for sub 750ft CEPs

The Flak would tear you a new one and your losses would be severe and unsustainable over Europe.

Bomb in smaller formations,

The fighters would tear you a new one.

Increase intervals between bomb groups to reduce target occlusion

Debatable practicality but I think the idea might have had some merit.

Reduce the width of combat boxes,

Increases your losses to fighters

Switch to an all B-17 force, as they were more accurate bombing platforms than B-24

That would hardly "fix" the problems of bombing from alt in 1944. The B-17 was not some superbomber it had a norden sight and dropped iron bombs.

Increase the level of training for crews, particularly for pilots, bombardiers and navigatiors

There was a war on and I think they were as well trained as you could reasonably make them. Trained better than most in fact by 1944.

Improve meteorological forecasting, particularly wind directions at targets

They already did that.

Never visually bomb through anything more than four tenths cloud,

That's a lot of bombers jetting their loads for nothing.

Abandon blind bombing techniques

Nice to say but not practical in Europe.

Introduce pathfinder aircraft

They did that with H2S. They are a partial fix to the technology of the day.

Reduce or eliminate use of fragmentation bombs and incendiaries

Targets burn

I am arguing that a combination of circumstances - battle experience and history, doctrine, effectiveness evaluations, the psychology of the commanders and the limitations of tactics and technology of the period - essentially forced de-housing and area bombing on Bomber Command, and resulted in the 8th AF adopting techniques that were precision bombing in name, but area bombing in practical effect (at least for missions involving anything more than 4/10ths cloud cover).

Completely agree.

[bozon]

The bombing accuracy of heavy bombers could not be improved in a drastic way, especially prior to 1944.

At the time, the only two ways to hit a building with a bomb with any certainty was to either drop from low altitude (mosquito style) or dive bombing. The allied pretty much dismissed both options and insisted on solving the problem with even more and bigger heavy bombers, which of course did not work very well.

Dive bombing by light bombers is something that the allied reserved exclusively for naval warfare. In that role they proved successful even though largely done by obsolete models. The allied should have kept a much smaller heavy-bombers force and divert the resources towards long range light bombers with low altitude and/or dive bombing capabilities. Essentially, long range fighter-bombers designed for that role.

[Karnak]

The Royal Navy ships would have been covered by surviving forces of RAF Fighter Command.

Or do you actually think the Brits would have not pulled their remaining Spitfires and Hurricanes back to use as cover for the navy's defense against invasion and would instead have let it be ground all the way down once it became apparent that the Luftwaffe was about to win?

The RAF would not have had to contest the skies for long and while the RN would have lost some ships, what would have happened to the Wehrmacht on those barges would have been far, far worse.

As to the AA, the KGV class BBs actually had pretty good AA.  PoW lost ~90% of it to the first torpedo hit, which by happenstance hit where her armor was weak from a German bomb strike that landed right next to her when she was being built.  It took out the power to most of her guns and jammed her rudder.

That said, I am not sure if KGV was in service in 1940, so that may be all moot.

[artik]

The bombing accuracy of heavy bombers could not be improved in a drastic way, especially prior to 1944.

At the time, the only two ways to hit a building with a bomb with any certainty was to either drop from low altitude (mosquito style) or dive bombing. The allied pretty much dismissed both options and insisted on solving the problem with even more and bigger heavy bombers, which of course did not work very well.

Actually there was another way...

Lancasters were exceptional bombers in the WW2 warfare mostly due to their contribution to hitting high value targets. But that was a task that requires experience and training - the 617 was AFAIR the only squadron that did it.

The 617 RAF squadron used Tallboys and SABS bombsight (similar to Norden but proved to be more accurate also probably due to high level of training) and were able to hit the target with CPR of around 150m and less.

Given the power of Tallboys and Grand Slams and the high precision of bombing  thanks to the state of the art technology and the highly specialized training it was "the laser guided weapon" of these days.

They managed to destroy bridges, U-Boat docks, fortifications and even ships.

Finally 617 probably was the greatest example of high "long range heavy bombers" were effective. But it was also in highly specialized task with highly trained crew.

[Jabberwock]

Squire,

The recommendations I listed are not my own inventions. They were made either during the war or immediately after, based on the results achieved during the war and reported by the operational research groups. These things were known to work to improve accuracy.

How does that increase accuracy in any significant way? in any case various types were tried by the RAF and none increased bombing accuracy overall by any great degree.

That's not what the US operational research groups found. The 1000 lb bomb was more accurate than the smaller 250 and 500 lb weapons. The smaller bombs tended to tumble more on release before stabilising in the airflow, and were more affected by crosswinds, causing greater drift from the aiming point.

The Flak would tear you a new one and your losses would be severe and unsustainable over Europe.

Correct. I was discussing what would have made bombing more accurate though, not the implications of the tactics. Bombing form 11,000 to 15,000 ft was seen at the best for accuracy - lower and you were too affected by turbulence, higher and CEP starts to widen again.

The fighters would tear you a new one.

Correct, see previous answer. Formation sizes were reduced for some missions from about two thirds of the way through 1944 onwards. This had a positive effect on accuracy.

  Debatable practicality but I think the idea might have had some merit.

It was shown to work. Several ops in 1945 against 'milk run' targets had much wider group spreads, with appreciable results.

Increases your losses to fighters

Again, see answers to #2 and #3. Several different combat box formations were trialed in the ETO and PTO. Smaller boxes had better accuracy. I'm not discussing practicality, I'm discussing methods of improving accuracy.

That would hardly "fix" the problems of bombing from alt in 1944. The B-17 was not some superbomber it had a norden sight and dropped iron bombs.

Correct, the B-17 was not a superbomber. However, it was a more stable bombing platform than the B-24, was easier to pilot and assemble and tended to 'wander' less during a bomb run. B-17 groups consistently had better CEPs than B-24 groups in 8th AF service.

There was a war on and I think they were as well trained as you could reasonably make them. Trained better than most in fact by 1944.

Better than most still doesn't reach the potential for accuracy that the USAAF had but failed to achieve. Better trained and more experienced crews had improve accuracy over fresh crews, particularly those that had seen no combat.

  They already did that.

high altitude meterological forecasting was called for time and time again by experts, with almost bugger all reaction. They didn't even begin to start correcting for the jet stream until mid 1943.
 

That's a lot of bombers jetting their loads for nothing.

In 1943, you can find missions where 100-200 bombers failed to bomb because of lack of visibility. As the war progressed, this squeamishness about not bombing without visibility went away. Bombing thorough 5/10ths cloud dropped the number of bombs with 1000 ft of the aiming point from 30% to 9.4%. Bombing with H2X and 8-9/10ths cloud dropped this to 1%.
 

Nice to say but not practical in Europe.

Again, not discussing practicality.

They did that with H2S. They are a partial fix to the technology of the day. 

Pathfinder aircraft were used in a minimal and ineffective way. A wider and earlier introduction would have done much to improve accuracy.

  Targets burn   

Yes, but incendiaries, particularly the small 5-40 lb ones, were vastly less accurate than even conventional dumb bombs.

On the practicality side of things, only a few of these techniques/changes I listed are immediately usable for an air campaign. I acknowledge that most of them will require revisions of tactics, major and minor. These were the known solutions, at the time, to improving accuracy.

Many of them were ignored because they'd lead to higher losses. Some, like reducing the % of incendiaries, were ignored completely, or even reversed.

[PR3D4TOR]

The Royal Navy ships would have been covered by surviving forces of RAF Fighter Command.

It's silly, I know. The premise was that the RAF had been destroyed to the point of total Luftwaffe air domination over southern England.

[MiloMorai]

Oh and after the Channel Battle the Luftwaffe had plenty of experience in attacking ships. They sank more than 40 ships including four RN destroyers.

These RN destroyers were ......

[PR3D4TOR]

If we include the Norwegian campaign, Battle of France and Channel battles the Allied losses to Luftwaffe bombing were at least the following: Destroyers HMS Afridi, HMS Valentine, HMS Keith, HMS Basilisk, HMS Havant, HMS Whitley, HMS Brazen, HMS Codrington, HMS Wren, HMS Delight, minesweeper HMS Skipjack, armed boarding vessel HMS Van Dyck, troop ship HMT Lancastria. Also the French destroyers Foudroyant and Bison, and minesweepers Madeleine Louise and Notre Dames des Dunes. Polish destroyer ORP Grom. Royal Netherlands destroyer HNLMS Van Galen and minelayer HNLMS Thor. All were bombed and sunk by the Luftwaffe between May and July 1940. In addition a large number of smaller vessels and cargo and transport ships were bombed and sunk by the Luftwaffe. Mostly by Ju 87 and Ju 88 bombers, and most were sunk in the English Channel and off the coast of Norway.