Bomber offensive vs. Gemany: you are in charge

[parsifal]

Yes, I know, but it still was a device used to defeat German radars, in that particular case by giving the intruder advance warning of the nightfighters approach. Mossies had a standard tactic designed to turn the tables on the LW nightfighter...fly as part of the bomber stream, making out or foxing that they were one of the lumbering behemoths. Once the interceptor got to within about 1000 yds astern or even less (depending on the nerve of the Mosquito pilot, the AI Mk X would be quickly switched on, the Mosquito would open the thottle and carry out a relatively violent half roll and tight turn. The LW fighter would fairly quickly lose its radar fix on the Mosquito and in any event could not match the speed or turn rate of the Mosquito. They would usually panic and dive often smashing into the ground as they did. if they did not the Mosquito, with its far more efficient radar fit and near 180 search arcs would quickly re-aquire the interseptor and get on his tail, move into position astern of him and shoot him down.

Approximately 600 NJGs were shot down in this way., and it is believed several thousand more lost to accidents as a result of the extreme stress these tactics (and equipment placed them under). Staggeringlythere were only ever about 150 Mosquitoes mployed in this highly successful campaign.

 

[Siegfried]

Serrate was a what we could today call a RWR - radar warning receiver. It used the emissions of LW NF radars to detect them.

Serrate didn't work too well in practice, it kept going of from the multiple Luftwaffe radars, triggering of reflections.

Some late model Ju 88G had the "R" Version of their Radars which Incorporated tail warning and was considered very useful in evading RAF attack. German tail warning radars gave the range on a trace and so they could discriminate false alarms. The Naxos passive receiver gave direction to a bomber via its H2S but could also warn of night fighters.

These devices tended to be in short supply.

 

[parsifal]

Serrate didn't work too well in practice, it kept going of from the multiple Luftwaffe radars, triggering of reflections.

Thats completely contrary to both LW and RAF reports that used them. Bill gunston, who used it, and flew during the war, wrote a book on WWII nightfighters that includes considerable sections on the success of Seerrate.

Im not necessarily refusing to accept what you are climing, but if you are going to make claims like that, you should consider backing it up with something

 

[parsifal]

Further to the above, the late Henry Black, a recognized authority on the night bombing offensive wrote this in his book

"A number of authors have expressed the opinion that SERRATE was an operational failure but this is not the view of this author. The reduction in contacts during one period was due to the introduction of 'WINDOW' by the British and it had an unfortunate effect upon SERRATE Mk. II. This was remedied relatively quickly by the introduction of the clever design of SERRATE Mk. IV."


The Germans enjoyed a period of relative immunity from April through to July 1944 with the introduction
their SN-2 radar. However introductioon of this technology was not immediately complete....200 sets by April, about 1000 by July, moreover from July through to December, the RAF became increasingly adept by new technology at detecting even SN-2 equipped aircraft.

The use of the Lichtenstein SN2 led to the urgent development of SERRATE Mk IV as a method of homing onto this new German radar. The signals were presented to the Mosquito navigator aurally through a set of normal headphones rather than through a cathode ray tube (CRT). The DF (direction finding) is conveyed to the operator by coding the signal through 'dots and dashes' as with a Lorenz beam. This was necessary because of the number of CRTs already in use in group aircraft for the navigator to read, had almost reached their maximum.

When the Germans came to design their SN-2 radar, they were aware that the British were able to lock their A.I. radars on to their earlier designed radars. To make their new radar more secure, they selected a frequency within the band already used by some of their ground plotting stations - the Freyas. This simple approach met with considerable success because if a receiver was used to pick up the weaker SN-2 signals it would also pick up the more numerous and much stronger signals of the FREYAS. They also made their new radar to have facilities for front and rear scanning.

In the SERRATE Mk. IV, using audio-frequency filtering, the FREYAS signals were almost completely removed while the SN2 signals came through the headphones as a characteristic high pitched note with a pronounced tremor due to the 'Split' transmitter aerial. This became operational in January 1945.


The establishment of the frequency of the SN2 became an urgent problem to solve. It was not completely established until a Ju 88 landed in error at Woodbridge at July 13th 1944.

SERRATE Mk. IV and SERRATE Mk. IV(a) became available at about the same time. The Mk. IV was a modification of the TR 1143 receiver while the TR1430 was used as a basis of the SERRATE Mk. IV(a).

The use of the Lichtenstein SN2 led to the urgent development of SERRATE Mk IV as a method of homing onto this new German radar. Serrate MkIV was highly effective at this. The earlier Marks of Serrate continued to have some usefulness, because only a fraction of German NFs were SN-2 equipped for many months, and by the time they had been converted, the fighters of 100 group had fully converted to Serrate Mk IV.

 

[Siegfried]

In other words not "completely contrary" to LW or RAF reports since serrate was swamped by windows reflections from the radars it was to be homing on to, then progresivly rendered useless by the unknown SN-2 frequencies which were in anycase designed to conflate with ground based freyas. The Serrate Mk IV version only entering service in Feb 1945, a time the Luftwaffe was accepting deliveries of its own 9cm radars and was also operating the new FuG 218 Neptun radar.

Of course serrate no doubt worked as intended at times, these are the reports that we read about.

 

[parsifal]

In other words not "completely contrary" to LW or RAF reports since serrate was swamped by windows reflections from the radars it was to be homing on to

Black does not say that at all. Window had an effect, but it was not a complete blackout. Interceptions were still occurring, but not as many

, then progresivly rendered useless by the unknown SN-2 frequencies which were in anycase designed to conflate with ground based freyas. The Serrate Mk IV version only entering service in Feb 1945

,


It began entering service with 100 Group considerably before then, and. The LWs "window of immunity was shortlived and only partial, from May 1944 through to about September. SN-2 was introduced only slowly and barely kept pace with attrition. The Germans did achive an advantage, i will grant you, however that advantage was naything but a runaway victory in this fascinating aspect of the war. They were unable to translate the obvious advantages of SN-2 over serrate II before the British were abale to respond. the British response was a little late, but there was no great success for the LW.

a time the Luftwaffe was accepting deliveries of its own 9cm radars and was also operating the new FuG 218 Neptun radar

.

And the British were working on Serrate Mk VI to counter that very installation. The electronic war, like everything else in the war was about resources in the finish, and the Germans simply did not have enough resources to make a difference. They were never going to win a technological race.....they were a clever enginerering nation, but cleverness is only a part of the issue leading to success.

Of course serrate no doubt worked as intended at times, these are the reports that we read about.

Well true, but in the last twenty years or so, like a lot of views on the course of the war, there is a dedicated group of zealots absolutely committed to revising and rewriting the accepted versions of history, usually to cast the germans in the best possible light or reveal some oversensationalised aspect of the war that they 9the author) wants us to know about. only with careful examination of the facts can it be usually exposed that these claims are largely fraudulent . im sure you have read many of those sort of histories.

 

[tomo pauk]

Hello, gentlemen,
Maybe the electronic war at 20000 ft (give or take) deserves a thread on it's own?

 

[VBF-13]

Hello, gentlemen,
Maybe the electronic war at 20000 ft (give or take) deserves a thread on it's own?

Is that a polite hint?

Seriously, Tomo, this thread has been going on since March. Haven't you boys figured anything out, yet? This is totally not my area, but I've been lurking on this thread for at least a month, now. While I know that these missions were highly controversial, I'm wondering, what else can be said? You boys seem to have exhausted the subject.

 

[bbear]

Parsifal and Siegfried are exchanging very great stuff about how and when and what of the radiio waves campaign. But - why contend the sky at night in ETO at all?

I would like to ask whether the advantage really did change in 1940/41 from day ops to night. Knickebein/Gee.....I had thought that was accepted as the start of the modern path and the advantageous tactic at the time. But then i came here and started reading more

I've tried my poor answers to the why' question - less losses per bomb ton on target - but that seems to get diffferent rebuttal every 5 minutes as I look around . I've tried the Bombng Surveys (long procurement and resourcing cases for more money/status for air power or thats how they read to me), interpreting mchueks tables I find that data needs careful handling or it just shows whatever I want (the data deserve better than to be torured ) and I note parsifals referenced argument on attrition (a slightly different question).

If we just want to 'blow stuff up strategically' in ETO : night or day?

Is there a really good independent and balanced assessment? Riffling through internet samples the contemporary ones are partisan or maybe written in passion. Modern ones are - variable. Some writen to please others seem - a bit bent. At least at my non-academic level.

 

[Glider]

Parsifal and Siegfried are exchanging very great stuff about how and when and what of the radiio waves campaign. But - why contend the sky at night in ETO at all?

I would like to ask whether the advantage really did change in 1940/41 from day ops to night. Knickebein/Gee.....I had thought that was accepted as the start of the modern path and the advantageous tactic at the time. But then i came here and started reading more.

I think the simple reply is that before the advent of long ranged fighters, the bombers could not live in enemy skies during daylight. If you wanted to bomb deep in the enemy area then you had to go by night.

 

[parsifal]

Gliders pretty much nailed it. In 1939, the RAF mounted a few raids by daylight on several targets in Germany. The RAF up to that time was as wedded as any of the major nations that the bomber would always get through. These raids suffered horrendous losses (about 50-70%). Some time later, in the latter part of 1940, the Germans mounted an effective night bombing campaign, in which the bomber losses compared to those they had suffered in daylight had reduced significantly.

In 1941-2, the only option and opportunity for serious offensibve action was via BC attacks. Some attacks were undertaken by daylight, over france and the low countries. Despite suffering greater losses than the LW, this campaign did achieve results, but the loss rates remained unnacceptable, and that was with massive fighter prrotection for most raids(in fact the bombersd apart from the raids o the KM and shipping did not achieve that much....it was the escorts protecting them and the attemtps to get the LW to come and fight that achieved the result. the only real option at that time was by night bombing for all attacks over Germansy. Britain simply could not provide a long range fighter escort, and could not afford the losses that a day campaign entailed.

Despite the apparent lack of direct success in those early years, the Germans were evidently concerned by the potential the campaign had. They poured massive amounts of resources into countering it, about 80% of the flak forces were deployed so as to counter BCs campaign, and the night fighter forcesand their ground based support soaked up about 30% of the LWs budeget. For an outlay repr3senting about 12% of Britiains military spending, the results were massively successful...not because they pulled existing units from the East, but because moneyand manpowoer otherwise spent on other progrmas were tied to countering the bombers.

Later in the war, once the Americans had basically destroyedor grounded the LW day fighte forces, BC returned to a day bombing campaign at least in part.

 

[tomo pauk]

Good post; if a defender must invest spend more (percentage-wise), than the attacker, that is not a viable defence.

About this:

In 1941-2, the only option and opportunity for serious offensibve action was via BC attacks. Some attacks were undertaken by daylight, over france and the low countries. Despite suffering greater losses than the LW, this campaign did achieve results, but the loss rates remained unnacceptable, and that was with massive fighter prrotection for most raids(in fact the bombersd apart from the raids o the KM and shipping did not achieve that much....it was the escorts protecting them and the attemtps to get the LW to come and fight that achieved the result. the only real option at that time was by night bombing for all attacks over Germansy. Britain simply could not provide a long range fighter escort, and could not afford the losses that a day campaign entailed.

We can note that, after Op, Barbarossa (and contary to 1939 - mid 1941), Luftwaffe fielded far less fighters (and other planes) in West. Two JagdGeschwaeders were deployed west of Rhine. Compared to majority of RAF's assets.
Those two JGs were able to choose when to fight and when to stay away, because the Rhubarbs similar operations were involving 50-60 RAF's bombers, with hundreds of fighter acting as cover. No sane LW commander will send his planes against that force - the gains would be low, the risks for his outnumbered force too high. When the LW commanders decided that it was a time to act, they did, and RAF suffered disproportional losses.
RAF never tried to 'entice' the LW with, say, 500-600 bombers*. Bombing, in France Low countries, the under-construction submarine pens, LW, KM and Heer assets, fuel infrastructure, electrical infrastructure etc. That way the LW commander must act, scrambling his fighters to trade blows both against bombers and fighters. Will his fighters be able to land safely at cratered runaways? Even trading one bomber and one fighter (RAF), for one LW fighter, how many days the 2 JGs can withstand before they're bled dry?
In the same time, make night harassment attacks, so the Germans must have two shifts of manpower to man the guns, while increasing ammo expenditure gun wear.

Now before people rightly say that Spitfire V was not suitable for long range work, the shortcomings surfaced up from mid 1941 should lead to installation of more fuel for upcoming 1942. Main fuel tankage up to 95 IG, or rear fuselage tank for combat purposes, or an earlier introduction of wing leading edge tanks, or a combination of those 3 options.

*730 bombers in RAF's service in July 1941.

 

[parsifal]

We can note that, after Op, Barbarossa (and contary to 1939 - mid 1941), Luftwaffe fielded far less fighters (and other planes) in West. Two JagdGeschwaeders were deployed west of Rhine. Compared to majority of RAF's assets.

True, however, the germans did retain well over 1000 aircraft in the west and over Germany exclusive of transports and trainers. There were roughly 140 day fighters in the Reich defences and about 90 fighters in southern Norway and Denmark. All of these resources were available for any major incursions by day over Germany

Those two JGs were able to choose when to fight and when to stay away, because the Rhubarbs similar operations were involving 50-60 RAF's bombers, with hundreds of fighter acting as cover. No sane LW commander will send his planes against that force - the gains would be low, the risks for his outnumbered force too high. When the LW commanders decided that it was a time to act, they did, and RAF suffered disproportional losses.

Correct, the LW refused to fight except when the situation or the odds favoured the. According to galland this was very demorqalising for them, and even though RAF operations came at a high cost, it won for them control of the channel and the port districts on both sides of the ditch.

RAF never tried to 'entice' the LW with, say, 500-600 bombers*. Bombing, in France Low countries, the under-construction submarine pens, LW, KM and Heer assets, fuel infrastructure, electrical infrastructure etc. That way the LW commander must act, scrambling his fighters to trade blows both against bombers and fighters.

Opinions will vary I am sure, but I think service politics comes into play heree. 2 Group and Coastal Command were the day bomber forces tasked with prosecuting and achieving control of the channel, along with (for most of the time) about 18 fighter squadrons of FC. 18 squadrons is not that big an advantage over the 190 or so fighters of the defeding german forces incidentally.

The air commanders tasked with attacking targets in France were siomply not given access to the resources you are talking about. 2 Group was a force of about 6 squadrons, armed mostly with blenheims. moreover, elsewhere you talk about a force structure of 791 a/c. True, if you include everything, including OTUs, and aircraft like Oxfords and Ansons. Throughout 1941, BC was never able to mount raids stronger than roughly 250-300 aircraft. Harris, and his famous 1000 bomber raid, was only possible after a near three month sojourn, and then only by including everything in the force structure....an unsustainable effort

Will his fighters be able to land safely at cratered runaways? Even trading one bomber and one fighter (RAF), for one LW fighter, how many days the 2 JGs can withstand before they're bled dry?

Whilst acknowledging your point about "forcing" the germans to defend, the Germans never felt compelled to defend any airspace in France. on those few occcasions when threats to airfields were mounted, and the germqans were unwilling to to fight for that space, they simply transferred to other fields temporarily. The LW with several times the numbers of bombers a year earlier could not achieve this, why would the RAF, even if attacking at full strength be expected to do any better?

In the same time, make night harassment attacks, so the Germans must have two shifts of manpower to man the guns, while increasing ammo expenditure gun wear.

Agreed.

Now before people rightly say that Spitfire V was not suitable for long range work, the shortcomings surfaced up from mid 1941 should lead to installation of more fuel for upcoming 1942. Main fuel tankage up to 95 IG, or rear fuselage tank for combat purposes, or an earlier introduction of wing leading edge tanks, or a combination of those 3 options.

You would think so, given the increases in range achieved for the later marks of Spit. it was the lack of range that made the ofensive over france so frustrating and limited

*

730 bombers in RAF's service in July 1941

.

As I said, thats everything, the reality was a lot smaler than that.

 

[tomo pauk]

True, however, the germans did retain well over 1000 aircraft in the west and over Germany exclusive of transports and trainers. There were roughly 140 day fighters in the Reich defences and about 90 fighters in southern Norway and Denmark. All of these resources were available for any major incursions by day over Germany

In Norway, out of 52 Bf-109E/T, only 26 were serviceable; retreating those from Norway gives Coastal command free reign in coastal waters there. In Germany and Denmark, only ~40 serviceable Bf-109. We can add some 80 Bf-110, from Norway, Denmark and Germany.
Luftwaffe Orders of Battle 24 June 1941, 27 July 1942, and 17 May 1943

Correct, the LW refused to fight except when the situation or the odds favoured the. According to galland this was very demorqalising for them, and even though RAF operations came at a high cost, it won for them control of the channel and the port districts on both sides of the ditch.

Unfortulately, the Channel ports were not where the sub pens were.

Opinions will vary I am sure, but I think service politics comes into play heree. 2 Group and Coastal Command were the day bomber forces tasked with prosecuting and achieving control of the channel, along with (for most of the time) about 18 fighter squadrons of FC. 18 squadrons is not that big an advantage over the 190 or so fighters of the defeding german forces incidentally.

If I'm counting right here, the 'home' RAF FC squadrons were counting far more than 18 squadrons; the notable 11th Group having 26 squadrons on their own? Sure enough, not all the fighters will not be based in Channel front, but gives RAF a sure numerical superiority vs. 2 JGs.

The air commanders tasked with attacking targets in France were siomply not given access to the resources you are talking about. 2 Group was a force of about 6 squadrons, armed mostly with blenheims. moreover, elsewhere you talk about a force structure of 791 a/c. True, if you include everything, including OTUs, and aircraft like Oxfords and Ansons. Throughout 1941, BC was never able to mount raids stronger than roughly 250-300 aircraft. Harris, and his famous 1000 bomber raid, was only possible after a near three month sojourn, and then only by including everything in the force structure....an unsustainable effort

You can go here, where our, rather reliable, vincenzo gives 53 bomber squadrons in service. Planes ranging from Blenheim, Hampden, Whitley, Wellington, Strirling, even few had Hallifaxes and Fortresses. No Oxfords nor Ansons there.

Whilst acknowledging your point about "forcing" the germans to defend, the Germans never felt compelled to defend any airspace in France. on those few occcasions when threats to airfields were mounted, and the germqans were unwilling to to fight for that space, they simply transferred to other fields temporarily.

The Germans rightly concluded that RAF bombers incoming in penny packets are hardly to make any damage, let alone when they uncovered ruse of bombers acting as bait for RAF trap. With hundreds of bombers making their presence felt, there is no ruse - LW must scramble kill bombers. Not the greatest thing if RAF flies twice the number of fighters as cover.
If LW moves away, all the better.

The LW with several times the numbers of bombers a year earlier could not achieve this, why would the RAF, even if attacking at full strength be expected to do any better?

LW in BoB was not fighting against an opponent that just deployed bulk of it's fighters in some other major theater of war.

You would think so, given the increases in range achieved for the later marks of Spit. it was the lack of range that made the ofensive over france so frustrating and limited

Unfortunately, later Spits, deployed in ETO, featured better range only from late 1944, when it was no more the issue with W. Allies firmly established in Continent.

[BC compostition strength]As I said, thats everything, the reality was a lot smaler than that.

Covered above.

 

[bbear]

Thanks for the answers. So day or night? Is definitely night any time from 1939 when the RAF learned the leson until 1942, and for deep missions until around April 1944. The limiting factor being range of day fighters in both cases. But...

With hindsight (or contemporary thought) the only point of bombing was to provoke disproportionate expenditure of resources by the enemy to defend a sky he had no real strategic interest in defending except when he could make tactical in-roads into your air force? So over France this was like the early part of BoB. LW trying to bring the RAF FC into combat over the channel shippping, Parks being cagey, never over-extending - feints and bluffs, flurries amd decoys, the occaisional non-decisive 'Jutland' in the sky. Over German cities the LW might say 'why interfere with an enemy who is making a mistake' - let the flak and mechanical fault and navigation error and weather and the channel do the work and let the night fighters take the easy prey on the way in. Have I got the right picture?

If so, am I right in thinking that the most important 'choke point' of all was pilots? I seem to rember that was priority 1 in the BoB for Dowding. Target 1 in any resonable AWPD - Not the LW might in planes or airfields or ball bearings or even fuel and transport - but in crew especially pilots. So a 'kill' is not a 'kill' unless someone got, well, killed?

And if that's right is the real reason for the suden collapse of the LW as seen by decline in bomber losses around May 1944 just that - with the range of fighter pilots extended the LW ran out of air to retreat to so our numerous hawks shot down their numerous chicks - from whch position no recovery is possible no matter what material investment is made - because pilots need a long period of safe flying before they can fly safely - let alone fight on equal terms? After which all those expensive flak guns and radar are almost worthless scrap iron. Apart from srvining the few remaining experts, and the 262s we couldn't catch.

In which case Dowding or Parks would have had the answer to best strategic bombing policy in historical time. No hindsight needed. Pity they got canned or posted for the sheer cheek of winning something.

That may be a flight of fantasy, probably is - I'll post it in case anyone bites.

 

[parsifal]

There was actual damage arising from bombing, including night bombing. The percentages of lost potential arising from bombing is sharply debated. Some argue the losses to production were virtually nothing, others argue up to 50% of late war production was lost.

The USSBS provides figures foir the US forces but tends to downplay the efforts of BC. The USSBS estimates about 40% of total German potential. There is a far less well publicised British source, which estimates the losses to production in 1943 amounted to about 17% of estimated potential. In 1944, there was an increase to about 26% of war potential.

as I said at the beginning, these figures are disputed. However if you accept that they have some validity, the preliminary work undertaken by the RAF in 1941-2 played its part in learning the necessary lessons needed for that result.

For me, the figures are thoroughly plausible. I find it hard to believe that the Germans would not react so violently and devote so many of their resources, unless the bombing had some impact on their economy

 

[bbear]

Thanks once more. I'll just remember for future reference that when people speak of attritional loss in enemy air forces they may primarily be talking about pilots.

As for industrial production losses, it must be almost impossible to tell one effect from another - for example all BC/8th activity vs drafting of younger workers into uniform vs territory gains/losses.

It would be one heck of an analysis. At least it seems agreed that bombers posed sufficient threat over Germany by day to force the attack by LW fighters. But not so over France or other occupied nation.

I must read some books now and the Bombing Surveys or what i can get of them- carefully this time. I won't surface for a while.

 

[stona]

Just happened across a passage in "Rise and Fall of the German Air Force", a British Air Ministry report published post war. It doesn't relate to the effects of bombing on German production but rather specifically on the Luftwaffe.

"From early 1943 until the Allied landings on 6th June 1944,the combined Anglo-American air attack on the Reich was the dominating factor in the air war.It resulted in the reduction of the German Air Force in the Mediterranean to a size at which their influence over the course of operations was negligible. It resulted in the transfer from Russia to Germany of single-engined and twin-engined fighter units at the very moment when the growing superiority of the Soviet Air Force required a strengthening of German fighter opposition.And,above all else,it enforced a change-over from bomber to fighter,from offensive to defensive equipment,which irrevocably altered the whole composition and character of the German Air Force."

Not a bad list of by-products.

Cheers

Steve

 

[Tante Ju]

I would say the British Air Ministry's own post war self-justification for its existence and horrendous wartime budget makes a poor source for reliable information.

Especially the claim of fighter transfers is a great stretch, since these always happened in bulk when Allied ground troops actually made a landing. See Allied landings in Siciliy/Italy, or in Normandy. It had little to do with the 'air attack' and very much with the ground troops appearing.

Winter transitions back and forth between the EF and the WF were commonplace in the winter, but simply made better use of resources. Bombers that could not fly in winter conditions in Russia could merrily do so in the MTO.

 

[stona]

Why do you think they compiled such reports?

Cheers

Steve