Defeating Bomber Command

[wiking85]

Given that the Battle of Berlin was a disaster for the RAF BC was there a chance for the Luftwaffe to inflict such a defeat on BC prior to early 1944? Is there a conceivable situation that BC would have to abandon massed night bombing of German cities permanently during the war (until something like the oil campaign succeeds)?

 

[wiking85]

I supposed I'll start the discussion off on the potential success of the intruder operations up to October 1941 when Hitler cancelled them. Had that offensive gone on longer it would have hurt the build up of BC into 1942, potentially making the 1000 bomber raids unfeasible until the RAF got their Mosquito night fighters in enough numbers to halt the intruders, which would probably be some time in 1943. Of course by then the Me410 would be available and was a decent intruder itself and fast enough to give the Mosquito issues with interception. Would this have been enough to blunt BC and potentially head off the Baedeker Blitz? Would it make the Luftwaffe night defenses worse due to lack of experience against the heavy BC raids?

 

[wuzak]

What about Beaufighter NFs? I'm sure they could have put up a decent defence against night intuders made up, I assume, mainly of Ju 88s?

 

[wiking85]

What about Beaufighter NFs? I'm sure they could have put up a decent defence against night intuders made up, I assume, mainly of Ju 88s?

Forgot about them. They were barely faster than the Ju88Cs (stripped down and more aerodynamic, thus faster than the Ju88A4 by 35mph) used for the intruder operations (14km faster) making it very difficult to intercept them. In fact by late 1941 when the intruder operations were cancelled they were at their most successful, so I don't think they were successful at stopping them. AFAIK the night operations over Britain really only because dangerous in 1943 and the Beaufighter was phased out for defensive operations in late 1942 when there were enough Mosquitos to take over; the Beaufighters were much slower, but useful as intruders themselves over Germany.

 

[wiking85]

Here is some info about the historical intruders, which I know Erich writes about on this board:
Axis History Forum ? Intruder Operations Over England

 

[davebender]

Pin pricks. Germany would need a lot more light bombers to make this effective. Cancelling daytime portion of BoB is only way to make enough German aircraft available.

Historical spring 1941 German night bomber losses were less then 1% of sorties. So RAF night air defenses aren't an issue. Luftwaffe lost more night bombers from navigation error then from RAF night fighter aircraft.

 

[wiking85]

Pin pricks. Germany would need a lot more light bombers to make this effective. Cancelling daytime portion of BoB is only way to make enough German aircraft available.

Historical spring 1941 German night bomber losses were less then 1% of sorties. So RAF night air defenses aren't an issue. Luftwaffe lost more night bombers from navigation error then from RAF night fighter aircraft.

That is before the point I mentioned early on and before the Kammhuber really realized BC was a threat they needed to focus on.

 

[Glider]

Clearly a Mosquito is a much better performer than a Beaufighter but I wouldn't be quite so disparaging about the Beau. The intruders are likely to be at cruising speed not max speed and this would make them vulnerable to the Beau which under GC would be able to use all its performance when required. In daylight combat the Beau had a clear advantage over the Ju88 and over the Bay of Biscay the JU88 units were ordered not to tackle the Beaufighter unless they had a clear numerical or tactical advantage and were treated with respect.

By 1942/3 the RAF defences were in much better shape with the Defiant replaced and German losses I expect would have been higher than in 1941 when the RAF were still learning how to go organise and get the Beaufighter up to strength. Its also worth remembering that the radar on the RAF fighters was more advanced than the Luftwaffe and that in night fighting is a huge plus.

 

[stona]

Interception at night has less to do with the aircraft used and more to do with the GCI and AI radar systems being used.

The British introduced AI Mk I and II radar prematurely. They barely worked. The first successful AI Mk III interception took place in July 1940 but the gap between ground control and AI performance was too great until the first real GCI was available. AI radar in 1941 (Mk III to later Mk V) had a range of at best two miles. the GCI radar controller had to get the interceptor to within this distance for it to have any chance of 'seeing' the target and closing to within visual range to make an attack.

The first experimental centimetric AI radar wasn't even flown until March 1941. Two experimental sets were available in June. To cut a long story short the RAF lacked centimetric AI radar until late 1942 when the interim Mk VIII sets began to be delivered. Until then the 1.5 meter Mk V was being used to good effect in conjunction with GCI. Conversion to the superior centimetric sets took place throughout 1943.

The earliest GCI radars were essentially based on a modified, mobile, CHL aerial. The first six sets were hand made and handed over to the RAF at the end of January 1941. They must have worked because contrary to what is posted above Luftwaffe losses by night rose significantly. I have a figure of 7% for May 1941.

By the end of 1941 there were 29 GCI radars in operation. In June that year it had been decided to use the AMES Type 7 as the basis for the fixed GCI radar. This was a much superior system but only 2 were operating, plus 2 more experimental stations, by the end of 1942. It is fair to say that due to the reduced threat the programme was wound down. 13 mobile stations and 21 fixed stations were put on 'care and maintenance' at this time.

Had the threat from the Luftwaffe at night been maintained or increased in 1941/2 it would have been possible for the British to react. They certainly wouldn't have been putting GCI radar stations on 'care and maintenance' regimes.

Cheers

Steve

 

[wiking85]

The earliest GCI radars were essentially based on a modified, mobile, CHL aerial. The first six sets were hand made and handed over to the RAF at the end of January 1941. They must have worked because contrary to what is posted above Luftwaffe losses by night rose significantly. I have a figure of 7% for May 1941.

https://en.wikipedia.org/wiki/The_Blitz#Sorties_flown
Under 2% losses for May 1941 for the Luftwaffe. Source: "The Night Blitz". It was higher than previous months and for the first time exceeded losses from accidents, but it was a minor set of losses (55 aircraft out of 3800 sortees). The Luftwaffe actually expanded in overall numbers that month despite these loses (which included accidents and losses to AAA). By 1942 the RAF was able to intercept the slow He111s pretty regularly, which is how they inflicted serious losses during the Baedeker Blitz, but were not able to really inflict many losses on the Ju88Cs. It was really only the Mosquito in conjunction with improved ground intercept radar and AI radar that really hurt the LW, but even as late as 1945 the LW was still inflicting intruder losses.

As to the cruise speed, the Mosquito bombers could be caught by LW NFs in cruise speed, but the problem is that they needed to sight them first and close before the bombers realized they were being followed and took evasive action. Same for the LW intruders, they were able to penetrate British airspace regularly without being intercepted, most being lost to accidents (landing/taking off and running out of fuel) and AAA more so than NFs.

 

[davebender]

By 1942 Luftwaffe Schwerpunkt was on Russian front along with rest of the Wehrmacht. If you want an effective interdiction campaign it needs to happen prior to June 1941.

 

[stona]

In May 1941 twin engine night fighters (that is Beaufighters with Mk IV AI radar) accounted for 25 Luftwaffe aircraft compared with 2 in February. This was due to the development of GCI and AI radar. It had little, or nothing, to do with the night fighter employed.
The figure is more significant because around mid May targets for British night fighters became much more scarce.
Cheers
Steve

 

[wiking85]

In May 1941 twin engine night fighters (that is Beaufighters with Mk IV AI radar) accounted for 25 Luftwaffe aircraft compared with 2 in February. This was due to the development of GCI and AI radar. It had little, or nothing, to do with the night fighter employed.
The figure is more significant because around mid May targets for British night fighters became much more scarce.
Cheers
Steve

The sortee rate in February was 1/3rd that of May due to bad weather. Its really had to make interceptions in that. Not only that, but the introduction of the Beaufighter enabled interceptions, because its top speed was about 150mph faster than the He111, which was able to outpace the Blenheim NF. The introduction of better AI radar certainly helped, but the major improvement was in the the quality and speed of the aircraft used as NFs.

https://en.wikipedia.org/wiki/The_Blitz#Potency_of_RAF_night_fighters

Moreover, the Blenheim struggled to reach the speed of the German bombers.
The Boulton Paul Defiant, despite its poor performance during daylight engagements, was a much better aircraft in the night fighter role. It was faster and able to catch the bombers, and its configuration was also beneficial. Placing its armament of four machine guns in a turret instead of fixed forward it could (much like German night fighters in 1943–1945 with their Schräge Musik configuration) engage the unsuspecting German bomber from beneath. Attacks from below offered a larger target, compared to attacking tail-on, as well as a better chance of not being seen by the bomber (so less chance of evasion), as well as greater likelihood of detonating its bombload. In subsequent months a steady number of German bombers would fall to night fighters.[146]
Better news was in the offing with the Bristol Beaufighter. It would prove formidable, but its development was slow.[146] The Beaufighter had a maximum speed of 320 mph (510 km/h), an operational ceiling of 26,000 ft (7,900 m) and a climb rate of 2,500 ft (760 m) per minute. Its armament of four 20 mm (0.79 in) Hispano cannon and six .303 in Browning machine guns offered a serious threat to German bombers.[147]
By April and May 1941, the Luftwaffe was still getting through to their targets, taking no more than one- to two-percent losses on any given mission.[150] On 19/20 April 1941, in honour of Hitler's 52nd birthday, 712 bombers hit Plymouth with a record 1,000 tons of bombs.[150][150] Losses were minimal. In the following month, 22 German bombers were lost with 13 confirmed to have been shot down by night fighters.[150] On 3/4 May, nine were shot down in one night.[150] On 10/11 May, London suffered severe damage, but 10 German bombers were downed.[150] In May 1941, RAF night fighters shot down 38 German bombers.[151]

The quality and speed of the aircraft mattered, which is why the Mosquito was barely shot down at night and the Bf110 was being withdrawn due to its slow speed relative to bombers by 1944.

 

[stona]

I disagree. The major improvement was in the coordinated night defensive system, that was due to the development of the two complimentary radar systems. Without GCI radar and competent controllers the airborne radars of WW2 were almost useless. Having a faster night fighter was obviously an advantage, but not critical.

In any case, to return to he original premise, the Luftwaffe never had the means to defeat Bomber Command at any time during WW2. It came closest when Bomber Command played into its hands and that wasn't in 1941.

Cheers

Steve

 

[davebender]

When was British ground control radar upgraded to provide height data? That's critical information for a night aerial interception.

 

[Glider]

My understanding was that they always gave a height indication. This at times wasn't that accurate but I believe it was always there.

The Beaufighter was critical as it had all the attributes of a nightfighter, obviously you need the infrastructure as well and one without the other made the whole thing a bit of a waste.

 

[stona]

When was British ground control radar upgraded to provide height data? That's critical information for a night aerial interception.

Yes. Those first six GCI radars were essentially a CHL aerial mounted on a turntable and modified to give height information. They were hand built at the Royal Aircraft Establishment and the Telecommunications Research Establishment.

They also used Plan Position Indicator (PPI) displays. Earlier displays showed one dimension only, that is slant range to target as a deflection on a time base across the cathode ray tube (CRT). A PPI display showed two, bearing and slant range, by having a time base as a radius on the CRT, pointing in the same direction as the aerial. This will be more familiar to those who have seen more modern radar displays. Returned signals, instead of producing a deflection in the time base were used to brighten up a spot at that part of the time base. By clever jiggery-pokery, turning down the general brightness and fiddling with relative contrast only the bright spot would be seen as the aerial's beam swept over the target, again familiar to those who have seen more modern displays.
Place a gridded map over the display and the geographical position of several targets could be accurately plotted at each revolution of the aerial. Scanning beam radar was born. It seems obvious to us now, but in 1940 this was a huge leap forward in interpreting the raw information coming from the radar.
The AMES Type 7 was introduced in the GCI role particularly because its better aerial had longer range, more accurate height finding and also a gap filling capability. Earlier radars had gaps in their vertical coverage for rather complicated reasons, the maths of which I've struggled to understand for a considerable time


Back to the Battle of Berlin. Whilst the campaign was a defeat for Bomber Command (whatever Harris later wrote) it never came close to destroying that organisation. The campaign was in two parts, from 20th August to 9th September 1943 and then from 16th November 1943 to the end of March 1944.

In this period 19 major raids went to Berlin, 10,813 sorties, 625 aircraft lost (5.8%)

At the same time 22 major raids went to other targets in Germany, 14,045 sorties, 678 aircraft lost (4.8%)

Berlin was a bloody nose, but not quite the disaster some would have you believe.

Cheers

Steve

 

[wiking85]

So given that the Mosquito was the only fighter that could reliably catch up to the Ju88C intruder, how would continued intruder operations past 1941 have impacted BC's build up into 1942?

 

[stona]

Not at all without a lot more suitable aircraft which were simply not available. How many Ju 88 Cs were in service between mid 1941 and mid 1942? I can't find a reliable number. I know I./NJG 2 operated a few against England during 1941.
Intruder operations, even by the RAF with a full array of more advanced electronic aids towards the end of the war, never amounted to more than a nuisance.

Also don't forget that had such a threat somehow emerged the British would have reacted to it.

Cheers

Steve

 

[wiking85]

Not at all without a lot more suitable aircraft which were simply not available. How many Ju 88 Cs were in service between mid 1941 and mid 1942? I can't find a reliable number. I know I./NJG 2 operated a few against England during 1941.
Intruder operations, even by the RAF with a full array of more advanced electronic aids towards the end of the war, never amounted to more than a nuisance.

Also don't forget that had such a threat somehow emerged the British would have reacted to it.

Cheers

Steve

Of course they would have reacted, but how long before that reaction becomes effective? AFAIK they were operating a Geschwader in October 1941 of Ju88Cs when the ops were cancelled, not sure thereafter. 960 were built before the Ju88G into online in late 1943, though IIRC the Ju88R, which was the Ju88C with BMW 801.
https://de.wikipedia.org/wiki/Junkers_Ju_88#Serienproduktion
About 164 Ju88Cs were built prior to the Ju88C6, though the first 40 were converted A-series versions and 60 of the Ju88C4s were converted. 60 Ju88C4s were built as heavy fighters. 4 C5s were built but were not successful, while 900 C6s were built starting in either late 1941 or early 1942 AFAIK. They ended production in late 1943 or early 1944 and switched to Ju88Gs.

According to "Warbird of the Third Reich" 57 were on hand for intruder operations in July 1941, not sure about October 1941 or thereafter; I know they were operating in Geschwader strength in the Mediterranean in 1942 and in April they got their first C6s. 760 C6s were built in 1943, the majority in the last 6 months.