Bomber Losses: USAAF vs RAF

A link on losses and other statistics

NOTE Best viewed with screen realization 1024 x 768,

With regard to losses in the Night bomber offensive, it was not possible to escort bombers in the sense of the US concept, however German aircraft losses were still extremely heavy. This is a facet of the fighting seldom reported, because it is not "sexy". Many German aircraft were lost in landing accidents, many to the intruder squadrons, that circled German airfields, to pick off German fighters as they landed and took off. Many more were destroyed by Radar equipped Mosquitos using Serrate and other technological advances. Basic tactics were for the Mossies to join the Bomber stream and act as "bait for the pursuing German NFs. Serrate would lock onto their AI. At about 1000 yds range, the Mosquito would execute a tight turn, pulling into the Germans Radar shadow (German radar did not have as wide a search arc as the later Mosquitos), There would be a few seconds of blackness for both aircraft, but if the manouvre was successful, the Mosquito would reappear on the tail of the German, with only the tail gunner now to protect the German.

One of the biggest reasons for British losses was their stubborn use of active radar as navigational and rear ward scanning technologies. This was an unmitigated disaster, which the LW capitlized on very effectively Their passive radar homing devices could pick up a British bomber fromover 100 miles. By using active means, the Britis had committed the mortal sin in night fighting....revelaing the position of their bombers. It was akin to two men each with a knife fighting in the dark....one turns the torch on to try and see bertter, he immediately become a target. This is what happened to British Bomber again and again

I would saythat the war in the air at night was a war fought in large measure as a technical race, with one side, than the other gaining the advantage. But as a broad (and dangerous) generalization, I would say thsat from July 1944 onward, with the release of later marks of AI in Mosquito squadrons to the escort/intruder functions that the Allies finally started to get the upper hand in the Night Bombing offensive

What bugs me is that U-boats had radar detectors called Tunis and later Naxos to warn them of danger from aircraft with radar.

Why couldn't bomber crews be equipped with similar for German night fighter radar frequencies ?

Kiwikid said:

What bugs me is that U-boats had radar detectors called Tunis and later Naxos to warn them of danger from aircraft with radar.

Why couldn't bomber crews be equipped with similar for German night fighter radar frequencies ?

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Although I am quite probably wrong about this, I suspect that production priorities were a major force here. The production of other systems like AI and ASV radar, H2S and Monica probably stretched British production needs to the limits. This means that although the technology was probably available, it just wasn't feasible to build and issue it on the scale Bomber Command required

There were passive devices fitted to detect German radar transmissions but they weren't present on most bombers. Everything like this adds weight and with constantly changing radar frequencies goes out of date quickly.

Active radar like H2S acts as a beacon for German nightfighters, but without it navigation is massively harder. It was felt the increase in the effectiveness outweighed the losses incurred.

There's a book on the history of 100 Group engaged in bomber support operations that has lots of detail on this subject.

H2S and Monica radars were not critical to finding the targets, and in the case of H2S it was manifestly mis-used. The most critical item to bombing accuracy was Oboe, which did not compromise the position of the aircraft nearly as much. However, it was felt by the brass in England that the bombers needed the ability to guide themselves onto the target (with Oboe they were told by a ground station when to bomb, after the target had been "marked" by an Oboe equipped Mosquito pathfinder). They allowed the bombers the ability to "self navigation though H2S, which was in effect, a terrain following radar. In any case H2S was suffered from a large "circular error" (a term used by Gunstan) that was many times greater than Oboe, so even though it was an aid to navigation and target acquisition, it was not critical .

Monica was a rearward warning radar (or RWR) that unfortunately merely acted as a beacon for the searching German Night Fighters. Monica had absolutely nothing to do with navigational or bombing accuracy, but as in the case of H2S was kept on board and used at the insistance by the brass to use them. They increased the RAF loss rates needlessly and massively. H2S was useful, but it should only have been used sparingly (perhaps switching the thing on for a few minutes as the bomber approached the target, to confirm for the crews that they were in the correct location) , and not left on for nearly the entire flight, which simply gave the Germans another radar signature to plot the bombers position. Monica was a backward step in my opinion, and gave little, if any, safety to the Bombers, and vastly simplified the German problem of finding the bombers. Its one of those quirks of victory that its disastrous effects appear to have been suppressed or at least forgotten after the war....a case of history re-written almost. I suspect to protect the reputation of people like Harris.....

Wiki has some very good articles that provide a good starting point into understanding the bewildering array of aids used by the RAF in their offensives against Germany

Oboe (and why it was developed into G-H)

http://en.wikipedia.org/wiki/Oboe_(navigation)

"Oboe used two stations at different and well-separated locations in England to transmit a signal to a Mosquito Pathfinder bomber carrying a radio transponder. The transponder reflected the signals, which were then received by the two stations. The round-trip time of each signal gave the distance to the bomber.

Each Oboe station used the radio ranging to define a circle of specific radius, with the intersection of the two circles pinpointing the target. The Mosquito flew along the circumference of the circle defined by one station, known as the "Cat", and dropped its load (either bombs, or marking flares, depending on the mission) when it reached the intersection with the circle defined by another station, known as "Mouse". There was a network of Oboe stations over southern England, and any of the stations could be operated as a Cat or a Mouse as the need demanded.
The initial "Mark I" Oboe was derived from Chain Home Low technology, operating at 1.5 meters / 200 MHz. The two stations emitted a series of pulses at a rate of about 133 times per second. The pulse width could be made short or long so that it was received by the aircraft as a Morse code dot or dash. The Cat station sent continuous dots if the aircraft was too close and continuous dashes if the aircraft was too far, and from these the pilot could make the needed course corrections.

Various Morse letters could also be sent, for example to notify the aircraft crew that the Mosquito was within a specific range of the target. The Mouse station sent five dots and a dash to indicate bomb release. The Mouse station included a bombsight computer, known as "Micestro", to determine the proper release time, there being no particular logic in carrying the bombsight on the Mosquito when it was under the control of the ground station.

Along with the range restriction, an earlier system called Oboe, had another limitation: it could only really be used by one aircraft at a time. As a result, the British rethought Oboe, and came up with a new scheme named G-H (also given as "GEE-H") based on exactly the same logic, differing only in that the aircraft carried the transmitter and the ground stations were fitted with the transponder. In this manner, it operated in a similar manner to the currently employed civilian DME system, with the aircraft following a DME arc procedure on one set, whilst using another set (tuned to a different transponder as close to 90 degrees apart as geography permits) to determine the point of bomb release.

Multiple aircraft could use the two stations in parallel because random noise was inserted into the timing of each aircraft's pulse output. The receiving gear on the aircraft could match up the its own unique pulse pattern with that sent back by the transponder. Each receive-reply cycle took the transponder 100 microseconds, allowing it to handle a maximum of 10,000 interrogations per second and making "collisions" unlikely. The practical limit was about 80 aircraft at one time.

The name G-H is confusing, since the scheme was very close to Oboe and not very much like GEE. The name was apparently adopted because G-H used GEE developments, operating on the same range of 15 to 3.5 meters / 20 to 85 MHz. It was about as accurate as Oboe.

G-H was key to Operation Glimmer, a diversionary "attack" during Operation Overlord that distracted and pinned-down German defences at Calais while the real invasion fleet was 200 miles away at Normandy. G-H-equipped bombers of 218 Squadron flew low, in tight circles, dropping Window over radar transponder-equipped small ships, in order to deceive the German radars that they were the main invasion fleet"

Gee

"GEE entered service in March 1942 and was accurate to about 165 yards (151 m) at short ranges, and up to a mile at longer ranges over Germany. At its extreme range, which was about 400 miles (640 km), it had an accuracy of 2 miles (3.2 km). Unlike the German beam systems where the bombers flew to their targets along the beam, the GEE pulses were radiated in all directions, so even if detected, they would not reveal the bombers' likely destinations. As the system was passive, unlike H2S, there were no return signals which could give away the bombers' positions to night fighters. "

G-H (or Gee-H)

http://en.wikipedia.org/wiki/G-H_(navigation)

"G-H was a radio navigation system developed by Britain during World War II to aid RAF Bomber Command.
G-H was a two station radio direction finder system. Instruments in the bomber measured its position from one station and distance from another. It could be used by up to 80 bombers from any one pair of stations. By using more than one pair of stations, multiple targets could be attacked at the same time without the aid of pathfinders and markers. Once a major part of Bomber Command was fitted with the technology, G-H became a most useful blind-bombing device.

G-H was used for the first time on the night of October 4/5 1943 when one Mosquito attacked Aachen; the trial was not a success. The second trial was on the night of October 16/17 1943 when nine Mosquitos attacked Dortmund, one was carrying out a G-H trial but its equipment failed and it had to bomb by dead reckoning. It was used for the first time in a large raid on the Mannesmann steel works at Düsseldorf on the night of November 1/2 when about half of the sets failed leaving only 15 aircraft to bomb the factory on G-H

Along with the range restriction, an earlier system called Oboe, had another limitation: it could only really be used by one aircraft at a time. As a result, the British rethought Oboe, and came up with a new scheme named G-H (also given as "GEE-H") based on exactly the same logic, differing only in that the aircraft carried the transmitter and the ground stations were fitted with the transponder. In this manner, it operates in a similar manner to the currently employed civilian DME system, with the aircraft following a DME arc procedure on one set, whilst using another set (tuned to a different transponder as close to 90 degrees apart as geography permits) to determine the point of bomb release.

Multiple aircraft could use the two stations in parallel because random noise was inserted into the timing of each aircraft's pulse output. The receiving gear on the aircraft could match up the its own unique pulse pattern with that sent back by the transponder. Each receive-reply cycle took the transponder 100 microseconds, allowing it to handle a maximum of 10,000 interrogations per second and making "collisions" unlikely. The practical limit was about 80 aircraft at one time.

The name G-H is confusing, since the scheme was very close to Oboe and not very much like GEE. The name was apparently adopted because G-H used GEE developments, operating on the same range of 15 to 3.5 meters / 20 to 85 MHz. It was about as accurate as Oboe.

G-H was key to Operation Glimmer, a diversionary "attack" during Operation Overlord that distracted and pinned-down German defences at Calais while the real invasion fleet was 200 miles away at Normandy. G-H-equipped bombers of 218 Squadron flew low, in tight circles, dropping Window over radar transponder-equipped small ships, in order to deceive the German radars that they were the main invasion fleet"

H2S

H2S radar - Wikipedia, the free encyclopedia


"H2S was a radar system used in various British bomber aircraft from 1943 to the 1990s. It was designed to identify targets on the ground for night and all-weather bombing. The early variants of the transmitter/receiver equipment were officially known as TR3159 (H2S Mk I/ASV VIB) or TR3191 (H2S Mk II).

On January 30, 1943, H2S radar was used by RAF bombers for navigation for the first time and so became the first ground mapping radar to be used in combat. Initially it was fitted to Stirling and Halifax bombers and provided ground mapping for navigation and night bombing.

This development using ten-centimeter radar, (actually 9.1 cm) was possible thanks to the development of the cavity magnetron. Later versions of H2S reduced the wavelength, first to 3 cm and then 1.5 cm at which wavelength the system was capable of detecting rain clouds.
On a raid to Cologne on 2/3 February 1943, a Stirling Pathfinder was shot down over the Netherlands. The H2S set it was carrying was damaged but not beyond repair (fortunately for the Germans it was only the second operational use of H2S), and, known as the Rotterdam Gerät, Telefunken was able to reassemble it, with the exception of the PPI display that had been destroyed. Eventually this led to the development of the Naxos radar detector, which enabled Luftwaffe night fighters to home on the transmissions of H2S.]

H2S was vital in the air battle for Berlin, a series of large raids on the German capital and other cities from November 1943 until March 1944. Berlin was out of range of radio navigation aids such as Gee and Oboe and often obscured by cloud in the winter, so at the start of the battle it was hoped that H2S would, by identifying the many lakes and rivers in the city, be a crucial aid to navigation. The H2S sets available at the start of the battle were not able to do so. It was not until after the night of 2 December when the H2S Mark III, which operated on a 3 cm wavelength and could identify open and built up spaces, was successfully used for the first time on operations, that it became possible to bomb Berlin accurately."

Erich said:

it would be good to do a comparison study of the ETO USAF bomber vs Bomber Command losses for a true picture year by year.

small notation the German Luftwaffe night fighter arm shot down some 7100 plus Bomber Command bombers during the war

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I know that German night fighters and their operations are your wicket Eric, but I find your contention that night fighters are responsible for "7,100 plus" of the 7,953 Bomber Command night losses (ie 89.2% of BC night bomber losses) a bit hard to swallow.

Particularly when I run into counter facts such as this, from the link that parsifal provided:

"Between July 1942, when detailed analysis started, and May 1945, 5,807 aircraft went missing on night operations. Of these 2278 (39%) were shot down by fighters, 1318 (23%) by flak and 112 (2%) were lost in collisions. But in 2069 (36%) cases the cause of loss is not known. Based on these figures the ratio of fighter to flak losses was very roughly 2 to 1. However because of the large number of cases when the cause was not known this ratio can only be a rough estimate."

As the quote acknowledges, these figures can only be a rough estimate, when more than one third of losses are to unknown causes. However, the RAF's own statistical analysis suggests that, even if evey single other night bomber loss was the result of a shoot down by a fighter, the nachtjager could of scored no more than 6,500 kills.

Couple of statistical rundowns:

If we suppose that Nachtjagers accounted for all the percentage of unknown losses, this would put NF kills of night bombers at about 5,950.

If we suppose that, of the unknown losses, they scored three out of every four (another 27% of the total) then this would put total night fighter kills of BC aircraft at about 5,150 of the total.

If we suppose that night fighters accounted for two out of every three of the unknowns (another 24% of the total), as the quoted analysis suggests, them nacthjager kills perhaps accounted for around 4,550 of the 7,953 total night bomber losses.

Now, I acknowledge that there were other RAF bombers lost at night, such as Costal Command and 2 TAF Mosquitos operating at night (a total of 565 lost between FC and the 2TAF, according to John Foreman's Fighter Command War Diaries), but I doubt
that these would account for more than 500 aircraft in total.

I also acknowledge that the RAF definately miss-attributed some night fighter kills to flak, particularly schrage musik equipped fighters.

Still, as I said earlier, I think it is highly unlikely that the nachtjagers accounted for almost 90% of total night bomber losses.

Going back to the passive radar warning equipment that could be fitted to bombers. One was fitted to RAF heavy bombers callled boozer. It gave warning that there were German NF's in the area by picking up the radar transmissions. However it caused so many pilots to take evasive action and other spoof readings it was quickly taken out of service.

H2S was fundamental in assisting with navigation and therfore the finding of the target.

Other small point that I have found was that NF Mossies were equiped with equipment that could trigger the German NF IFF equipment thereby helping the Mossies to ID the Germans planes in the forest of returns caused by the bomber stream. The germans countered this by switching off their IFF which caused some difficulty to the ground operators who had difficulty finding their own aircraft. Things like this tended to be temporary while new equipment was brought into service but shows how comples the situation was for the Germans.

QUOTE=Glider;503089]Going back to the passive radar warning equipment that could be fitted to bombers. One was fitted to RAF heavy bombers callled boozer. It gave warning that there were German NF's in the area by picking up the radar transmissions. However it caused so many pilots to take evasive action and other spoof readings it was quickly taken out of service.

H2S was fundamental in assisting with navigation and therfore the finding of the target.

Other small point that I have found was that NF Mossies were equiped with equipment that could trigger the German NF IFF equipment thereby helping the Mossies to ID the Germans planes in the forest of returns caused by the bomber stream. The germans countered this by switching off their IFF which caused some difficulty to the ground operators who had difficulty finding their own aircraft. Things like this tended to be temporary while new equipment was brought into service but shows how comples the situation was for the Germans.[/QUOTE]

Hi Glider

I didnt know about the problems with Boozer. As an early warning system it was very popular, since it allowed the bomber to take evasive action before the NF had closed to lethal range. A violent corkscrew in a heavy bpmber must have been a sight to see, but apparently greater chances of surivavl existed by that manouvre than by trying to slug things out with your tail gunner

The biggest issue I have however is with H2S/ It was essential only where the passive aids were not available, ie, at ranges of more than 200mils for Oboe, and 400 for Gee-h. At these lesser ranges the passive systems were far more accurate than H2S.

Gunstan in his book says "As it was this "king of the pack of TRE Devices" (as Rowe put it) was serving as a constantly switched on lighthouse telling the german fighters exactly where their targets were. What made the situation even more ludicrous was, with the availability of Gee and Oboe, providing far more accuracy and far safer to the aircraft using them, that H2S for targets closer than Berlin was serving no purpose".

So whilst it might be true that H2S was critical in the Battle for Berlin, it was completely unneccessary for the Ruhr Targets (and other targets below 400 miles range). It was far more accurate, and safer, to rely on Oboe and/Gee than to use H2S.

But even this is is not the whole indictment. The use of H2S was also flawed, and given the British knowledge of radar and passive detection systems should never have occurred. H2S should only have been used sparingly, Gunstan suggests for 10 seconds every two minutes. I would suggest it stay off completely until the bomber is within say five minutres of the target. As H2S was a terrain following radar, why was it necessary to keep it on all the time. Both Oboe and Gee could dod the same job eithout disclosing the position of the bomber.

So in summary, H2S was unneccessary for targets below 400 miles, and was far less relaible and accuratethan the passive aids that served alobgside of it. It only became necessary when targets outside the effective range of the passive systems were selected . Which make Berlin as the chief target of 1944 a very strange choice for target.

The second failure that could be levelled at the British was the way they used H2S, specifically by training aircrew to keep it on continuously, This had a disastrous effect on British Bomber losses

also need to consider that the british where 2-3 years longer in the war, so makes sense to me they would lose more bombers because of the longer time frame.

"I think I read somewhere" that BC crews believed H2S foxed German radar. Can't recall where I read that though.

For me the big missed opportunity was the decision not to develop the Oboe repeater system. It was tested in action before the Battle of Berlin, but the view of the time amongst their Airships was that H2S would be sufficient to do the job, especially given the limited number of boffins available.

The second failure that could be levelled at the British was the way they used H2S, specifically by training aircrew to keep it on continuously, This had a disastrous effect on British Bomber losses

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Parsifal
I agree with almost everything in your posting, I only deleted it to save space. The only bit I would comment on is the last sentance. Once the RAF knew that the Germans were on to them they did encourage the crews to use H2S as little as possible but the was little that could be done to stop the crews 'checking' their position. Generally there was a greater fear in the crews of Flak as opposed to NF which they felt they had more control over and a lot of planes were shot down by Flak because they wandered into flak areas.
To a degree this was countered by the latter versions of H2S having a feature that highlighted a NF if there was one in the area. Right now I cannot remember the name of this feature but will dig around and see what I can find. At least it gave some warning if a NF had homed on to them.

In one of the books I read there was a comment about the overconfidence in the bomber crews and their ability to handle NF's. You are probably aware that you could fit three people in a Beaufighter. One of the squadrons used to take bomber squadron leaders up and intercept bombers on their way home. This had some risk as any bomber seeing twin engined aircraft approaching at night would shoot first and worry about questions later. Time and again they took people up and were never seen. In the end Bomber Command asked them to stop doing this as it was bad for the morale of the bomber crews.

Glider said:

Clearly the British NF were not able to stop the attacks that was impossible but my understanding was that the German NF's were very concerned about the Mosquito NF's over Germany. Considering they were on their own without any ground control the British NF's did pretty well. The best that I have heard about was on Mosquito that shot down four German NF's in one night.

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Yes the Mossie NF's did do very well over Germany and the German NF's were definitely worried about the presence, but overall what I'm saying is that the bombers were virtually unescorted and their defensive armament wasn't very effective at night, its no wonder that they lost so many planes.

a little scan of a page from the book "The Right of the Line" this is about tactics used in the battle of Berlin Jan 44
"In the course of the battle, Bomber Command used every device that it could muster to outwit the defence . Window was freely distributed in vast quantities, airborne radar aids were used to defect night-fighters (but in fact this enabled the fighters to home in on the bombers) or to jam the enemy radar sets feints and diversions were practiced round about routes were taken . But nothing. it seems could mitigate the effect of the sheer distance to be travelled 1150 miles to Berlin and back .
This was far beyond GEE or Oboe ranges and as in turned out. the sprawling city was a poor reflector of H2S its geography offered no clear characteristic to show up on a screen. Too often Pathfinders and other leaders had to identify targets visually - and to: often these were covered by heavy cloud. Guns and searchlights, as might be expected with a target of such importance, were exceptionally numerous Ground controllers now directed the fighters tab area the bomber stream in groups instead of individually a far more effective tactic."

Watanbe
I don't entirely disagree with you. I was trying to explain that the RAF did what they could to escort the bombers given the limitations that they were under namely distance and technology and that they did have some success.

Re the defensive fire of the bombers I don't think it would ahve made much of a difference. At the ranges we are talking about 4 x 303 are still pretty effective and the vast majority of bombers were hit before they knew it.

I agree Glider. The RAF really did try everything it could, but its hard to escape the fact that the technology just wasn't available at the time. You can't defend against an object you can't see and you can't effectively radar jam if you don't have the technology. It was inevitable that they would lose large amounts of bombers but IMO they still had to carry on anyway. They basically destroyed all the key German cities.

I have found the addition to H2S that picked up any aircraft in the vicinity of the bomber when the H2S was in use. The code name was Fishpond.

As an aside I have found some comparisons of the accuracy of Oboe and H2S when bombing which may be of interest. In September 1944 it was calculated that Oboe had a typical error of 350m and H2S 1,800m.

Another factor is well, probably more on the NF thing. The airborne AI sets in WW2 aircraft were notoriously unreliable, they often failed to work properly. Also the latest AI sets were also used reluctantly by the British over Germany, they couldn't afford to allow any advantages in radar to fall into German hands.

Not sure how relevant it is in our debate, but it is interesting!

What, sabotage by the National Front? The bastards

well Jabber as I hurriedly post this the priovate homepage stats are incorrect, I must disagree with his sources as being authorative, I will accept the research of others from England, Germany and Holland besides elsewhere over the past 45-50 years as being more accurate in numbers lost to the Nachtjagd arm nd even then the 7100 I put down am sure can be question within a 100 kills or so not counting what the RAF flew over the Balitc into Soviet held territory

appreciate the link(s) provided and the discussion

gents remember with the SN-2d being jammed that FuG 350z was being used fully when equipped and the pilots also homed in on the huge amounts nightly of the Window dropped getting into the area(s) of most concentration.

v/r E ~