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blue up 29th Apr 2007 19:18

B17 v Lanc bomb load
 
Just read an article saying that the Lanc could carry 22,000lb of bombs against a max of 8,000lb for the B17. Is this correct??? Seems quite a difference.

Thanks

Archimedes 29th Apr 2007 19:56

The B-17 had a notably smaller bomb bay than the Lanc (impressive though the B-17's payload was at the time of its design) - although the 22,000lb figure is for the Grand Slam carrying Lancs rather than the standard maximum load (which was, IIRC, about 14,000lb).

Evalu8ter 29th Apr 2007 20:34

Don't forget that the B-17 could carry an overload (including external racks under the wings) of 17 600lb. Don't think it was used much, if ever, operationally due to parasite drag & other performance issues, but it proved that the basic design could haul a significant bombload.
Remember that the B17 was originally designed to threaten the US Navy's role of protecting the US mainland from an enemy navy. Therefore range and endurance were more important than absolute bombload.

evansb 29th Apr 2007 20:43

Yes, until the Boeing B-29 Superfortress entered service, Britain seemed to have a good handle on making true heavy bombers. The American built Consolidated B-24 bomber could carry 8,000-lbs, yet the HP Halifax could carry 13,000-lbs. The Short Stirling could carry 18,000-lbs. The B-24 and B-17 were, however, reasonably reliable, and available in quantity. The B-24 had good range and speed, but was more vulnerable to damage than the B-17.

The giant Douglas XB-19 would have dwarfed Britain's biggest bombers in shear size alone, had it entered overseas service. The XB-19 could carry 18,000-lbs. of bombs, and for short range missions, could carry in excess of 35,000-lbs of bombs. MTOW was 140,230-lbs.

India Four Two 29th Apr 2007 21:39

What I think is more interesting is the B17/Mosquito comparison. Here's an example of an often quoted piece of Mosquito lore:

It was said that the 2 man twin engined Mosquito could carry the same bomb load to Berlin as the 4 engined Flying Fortress with its crew of 11. It also did it quicker and used less fuel.
Can anyone confirm if this is true?

Saab Dastard 29th Apr 2007 22:23

The Mosquito was certainly capable of carrying over 2000 lbs to Berlin.

The bomber variant was specifically tested with the 4000 lb "cookie", although a more usual bombload would have been 4 or 6 x 500 lb "short fin" bombs.

The range with 4000 lbs was approx. 1500 miles, so Berlin & back with 4000 lbs would have been possible, though perhaps not at high speed, and assuming a pretty direct flightpath.

It is possible that later variants with more powerful Merlins could have carried a greater load, but whether any actually did I'm not sure.

SD

Load Toad 29th Apr 2007 22:31

There is an interesting comparison on Wiki here:
http://en.wikipedia.org/wiki/Maximum...-24_bomb_loads

Bomb load alone doesn't adequately explain what each aircraft type had to carry over what distance. The US Air Force was trying to use precision bombing during daylight and trying to defend their aircraft too and from the target. The RAF had decided night bombing was 'safer' and tended to bomb an area. Those two arguments themselves being gross over simplifications too.

ICT_SLB 30th Apr 2007 04:09

I remember going around the Fort Lewis Museum in Washington State in the early 80s. On display was (if I recall the label correctly) "an experimental bomb dropped from a B-17 and found on the ranges" - it was, in fact, an intact Tall Boy so obviously jettisoned not dropped as intended from altitude - maybe too heavy for the aircraft? Wonder if it was intended for use against the Yamamoto?

evansb 30th Apr 2007 07:07

B17/Mosquito bomb load
 
India Four Two, Yes, in the dark, solo, below radar, (i.e. low-level), and carrying specialized electronic counter measures tuned for the day that were NOT available to the U.S. 8th Air Force en-mass, the Mosquito was, indeed, a formidable weapon. The RAF Bomber Command was also not privy to many of the counter-weapons specially tuned for the day. Logistics made it very difficult to build, test, and install a counter-measure system that would work in every aircraft of the European Theatre. Also, the Mosquito was of wooden construction, being inherently non-reflective of radar signals, and she had a relatively large avionics bay in relation to her size, in addition, she had a somewhat forgiving aerodynamic envelope that would accomodate a few changes to her foil. Most importantly, she was faster than most of her enemies.

Yes, Simon, if we only had 750,000 more Mosquitos, the war could have been over earlier. The forests would have been denuded, but, cest le guerre.

Let us not forget the de-laminating of the Mosquito's empenage in the tropics. It took a while to formulate a better adhesive to prevent the high speed delamination.

henry crun 30th Apr 2007 07:53

evansb: It did not have to fly low level at night and carry specialized electronic counter measures to be formidable.

For quite a long time it was too fast at high level with a normal bomb load for the Germans to shoot it down at night.

dakkg651 30th Apr 2007 08:10

I thought the reason the B17 carried such a small bombload was because they didn't need much to destroy a German pickle barrel.

Gainesy 30th Apr 2007 08:29

ICT SLB,
The USAAF took some Tallboys after the war and modded them with radio guidance, I think the project was called Tarzan, so maybe you saw one left over from that programme?

forget 30th Apr 2007 08:43

Below from Bill Sweetman’s ‘Mosquito’.

(How many Mosquitos would it take to equal a long range 1,000 Bomber Raid with Lancs?)

---------------------------------


It has been argued that Bomber Command could have done far more damage to Germany, with far less loss of life among its own crews and far less wastage of wartime production capacity, had it embraced the concept of the fast unarmed bomber earlier. Certainly, the Command’s post-war policy reflected this experience, with its jet bombers being designed around advanced H2S and electronic countermeasures and relying on speed and altitude for defence.

It takes fairly simple arithmetic to calculate that the Mosquito in its ultimate form could deliver more weapons over the same distance than the typical heavy bomber, when the two aircraft were compared on the basis of crew man-hours, total engine hours and fuel consumption; also, that the average Mosquito could be expected to deliver far more bombs during its far longer life expectancy, and its crew could expect to survive a far longer tour of operations. The only serious weakness of this argument is that the relative invulnerability of the Mosquito was itself indirectly brought about by Bomber Command’s own policies. Because the RAF concentrated on producing the four-engined heavy bombers, the Luftwaffe’s main task was to destroy these; Germany’s aircraft-production chief Erhard Mitch accordingly opposed production of the Heinkel He 219 night-fighter, which was faster than the Mosquito, in favour of the slower Ju 88G, which was adequate to deal with the heavy bombers and could be built more cheaply than the He 219. The practical difficulties of a shift to the unarmed bomber philosophy would have been enormous at any stage (including the need to train crews to the high standards demanded for the Mosquito) and would have given the Luftwaffe time to re-equip with the He 219, undoubtedly increasing Mosquito losses.

The final Mosquito bomber version was the B.35, basically similar to the B.XVI but powered by the high-altitude-rated Merlin 114. It remained in front-line service with the RAF until 1953, when the English Electric Canberra replaced it. Even the B.35, however, was restricted to operational weights and loadings in peacetime which were well below those of wartime B.XVIs; the “war emergency” weights at which the B.XVI operated were 4,000 lb (1,815 kg) higher than the peacetime weights, which limited the Mosquito’s bomb-load to 1,500 lb (680 kg). These restrictions could, of course, be lifted in wartime, and were an excellent indication of the abuse which the Mosquito would put up with in the hands of a skilled and dedicated crew.

teeteringhead 30th Apr 2007 08:48

It was certainly the received wisdom at the time. I can recall in my youth aged, well-oiled cockney relatives bursting into wartime songs at family functions.

One I remember was to the tune of battle Hymn of the Republic (Glory glory allelluila (sp?)). Two of the verses were:

"The Yanks were flying Fortresses at forty fousand feet (x3)
With loads of ammunition and a teeny-weeny bomb"

followed rapidly by:

"The RAF were flying Lancasters at zero-zero feet (x3)
With no ammunition and a :mad: great bomb!" ;)

Dan Winterland 30th Apr 2007 09:36

Typical war loads for the B17 were closer to 4000lbs.

Agaricus bisporus 30th Apr 2007 11:43

Actually...

We're flying Flying Fortresses at forty thousand feet
We're flying over Germany to give the Huns a treat
We've bags and bags of ammo and a teeny-weeny bomb
And we drop the bastard from so high we don't know where it's gone

India Four Two 30th Apr 2007 12:14


For quite a long time it was too fast at high level with a normal bomb load for the Germans to shoot it down at night.
And with the introduction of Oboe, single aircraft raids could have devastating accuracy.

http://www.radarpages.co.uk/mob/navaids/oboe/oboe1.htm

Chris Royle 30th Apr 2007 18:14

The Mosquito was certainly a wonderful aircraft, but don't forget that the single engine performance was not good, especially after take off. Single engine safety speed was in the order of 190 mph, with lift off at bout 130 mph. It took a long time to retract the undercarriage and clean the aircraft up. A lot of aircrew were lost in this way. It could bite very hard.
Read Neil William's account of dealing with an engine failure after tale off at Booker in "Airborne" and Don McVicar's book "North Atlantic Cat", the latter telling the story of ferrying (inter alia) Canadian built Mosquitos to Europe.

Dan Winterland 2nd May 2007 03:45

My Granfather 'acquired' a Mosquito due to engine failure. He had a farm in Norfolk and one night in 1944 (I think) an aircraft crashed nearby. My mother remembers hearing an aircraft crash that night, but as there was a German raid on Kings Lynn docks at the time, the assumed it was a German bomber as it sounded quiet and the thought it was a long way away. The next morning, it was confirmed a German aircraft had been shot down and had crashed on a nearby farm.

However, in 1975, my Grandfather decided to drain a patch of Fen which had never been touched which was only half a mile from the farmhouse. As the water level dropped, a propeller blade appeared out of the fen, so he called the RAF historical branch. It turned out to be a Mosquito which had taken off from Great Massingham (I think) on a raid to Germany. The wreckage showed that it had suffered an engine failure and the crew obviously couldn't found it hard to manage as they had crashed soon after takeoff. It had been listed as 'Missing in Action' so it was not known where it had come down and it probably wasn't suspected that it had crashed so close to home. The left side of the wreckage was almost intact, and having being submerged in peaty water which has very little oxygen in it, had suffered very little deeriation. The right side however, had taken the impact and was badly damaged. The wreck was complete with crew and armament and gave the RAF bomb disposal crew some problems dealing with the bombs due to their being parly submerged in a bog.

The left wing looked almost perfect. I remember the red of the roundel being almost as brilliant as if it had just been painted. The engine was in good condition and I gather it was restored to running condition. The tyre in that nacelle looked perfect and was still up to it's original pressure and the left nav light worked when a battery was connected. Some parts went to BAe to keep their flying example airworthy.

I had some parts to the aircraft for many years, but gave them to a friend who had a small aircraft museum.

ICT_SLB 3rd May 2007 04:13

Gainsey,

IIRC, the bomb had the typical fixed offset fins that provide the spin stabilisation still in place and, as far as I can remember, no external mods (relative the versions on the side of the Clubhouse at Brooklands or, when I saw them, BAe Weybridge). Didn't the USAF remote control bombs have large box fins a la Fat Man?

Blacksheep 3rd May 2007 04:27


...and its crew could expect to survive a far longer tour of operations.
Tell that to Guy Gibson's Ghost... :hmm:

blue up 3rd May 2007 19:01

I flew a pair of ARV Super-2's to Oshkosh in 198? and met a 'local' who told me that he had travelled the length on breadth of the UK in an Aston Martin down unmade roads in the 1950's with Guy Gibson. I hadn't the heart to tell him.....
Anyhow, have a listen to the glorious sound of ....
http://www.mossie.org/sounds/mosquito_flypast.mp3
(PS Max volume in stereo is recommended)

treadigraph 3rd May 2007 20:12

Nice one Blue up! Took you at your word, not sure if my neighbours will ever talk to me again. Not that I'll be able to hear them...

Loved the stereo on the exhaust crackle.:ok:

Kitbag 3rd May 2007 20:24

Evansb said: 'Also, the Mosquito was of wooden construction, being inherently non-reflective of radar signals'
This is not strictly true, one could expect something wooden to have a low RCS, however, being effectively transparent to radar just meant that all those lovely metal reflectors under the skin (engines, fuel pumps, bomb fins, avionic boxes etc) were all now exposed and creating re-entrant structures, not to mention the two biggest sets reflectors on any propellor driven aircraft so, all in all, the Mosquito was not quite as stealthy as one might expect.
Still a damn handsome piece of kit though:ok:

rolling20 4th May 2007 09:34

Schoolboy
 
Im appalled at the lack of knowledge on here...surely every schoolboy knows the Lanc was a better hauler of explosives than the B-17?! Albeit that the Lanc was purely designed for just that purpose (bigger bomb bay) and didnt carry as much armament and had less crew as a result. A typical load to Berlin would be a mixture of HE and incendiaries, usually a 4,000lb er and several 1,000lb bombs, roughly 10-14,000lb depending on fuel load.

Further the Mosquito regularly flew missions to Berlin carrying a 4,000LB Cookie, which could be fitted in by modifying the bomb doors. They often flew relays of missions to Berlin, landing back home and taking off again the same night! They even bombed Berlin on Hitlers birthday in 1943 in daylight!

The reason that more Mosquitos were not produced were two-fold. Firstly they were of wooden construction and most of this production was dispersed around the UK in small workshops etc, before coming to a final assembly plant.
Britan did not possess enough skilled workers for this job and thus numbers were limited. Secondly,Britains war effort was 'geared' to heavy bomber production and it would have been far too difficult to change that programme
once it was in full swing. There were even problems trying to resolve the Halifax Mk 1 stall problem. Handley Page refused intially to change the rudder design as it would interfere with production!

Im not sure who it was, possibly RV Jones or Tizard who computed that a Heavy Bomber without turrets and extra crew members could have had an increase of 50mph to its speed. That would give the Lanc an estimated max speed of 335-340mph, which would have been more that adequate to see off the twin engined nightfighters of the day, plus it would have given them an advantage of being more manouverable.

The B17 also fought by day as a precision bomber and thus in theory didnt need as big a load, whereas Bomber Command was a creature of the night, having been mauled in December 1939 in daylight, and the policy was one of 'Area Bombing'.

I have often wondered if the Heavies had not carried so much weight with them and were pure haulers of explosives, what effect that would have had on the 'night bombing' of Germany ( as awful now, with hindsight, that policy was) Surviving crews often told of Bombers lightening themselves before they got to Germany to gain altitude.

Im sure we all have nothing but admiration for their courage in carrying out a task that will never thankfully occur again.

45-Shooter 1st Mar 2012 00:41

Understanding all the variables?
 
Many people fail to understand the great number of variables involved. The altitude required was a big one, range, including all course changes etc...
The facts are;
1. The Lanc bomb bay was long, narrow and low. It could carry 12 conventional 1,000 pound bombs. After some time in service, after the RAF chose to do night ops, it was modified to carry 14 - 1,000 pounders with short fins. Then later it was again modified to carry heavier bombs. The 4,000 pound "cookie" as it was known was designed just for this application as the standard 4,000 LC/HC bomb would not fit WO new bomb bay doors. The bay was sized to carry the 4,000 MC bomb which because of the thicker case was smaller in diameter. All other bombs were carried by specially modified planes WO bomb bay doors. The normal maximum bomb load of NON SPECIAL Lancs was 14,000 pounds.
2. The Lancaster's AVERAGE bomb load during the entire war was just under 8,000 pounds! See; The "Lanc", as it was affectionately known,[2] thus became the most famous and most successful of the Second World War night bombers, "delivering 608,612 tons of bombs in 156,000 sorties." @ Avro Lancaster - Wikipedia, the free encyclopedia
((608612*2000=1217224000)/156000=7802 pounds/mission)
Many Lancs had most of their deffensive guns and armor removed to improve aerodynamic performance.
3. The average altitude of Lanc missions was <19,000! This contributed greatly to the AVERAGE weight of bombs it could carry to any given target range. With very heavy loads at relatively long range, bombing altitude was less than 13,000'! At night it did not matter much. But in broad day light, such altitudes were suicide! Since the Lanc's service ceiling was under 25,000', if it HAD BEEN REQUIRED to fly much higher than 19,000' during day light, like B-17s and B-24s at 25,000', to avoid optically directed flak, the bomb load to any given range would have been about half of what it was! MUCH LESS THAN HALF! If missions had been required at 30,000' fuel would have had to have been off loaded to make the plane light enough to get to altitude and both bomb load and range would have been REDUCED TO ONE QUARTER of what it was statistically.
4. The cause of number 3 above was the supercharger systems of the various Lancaster's engine types. There were half a dozen major variants! ( Not counting the Bristol engined types!) Compared to the Turbo-supercharger + supercharger system on both the B-17 and B-24, it was hopelessly under powered and in-efficient at high altitude!
5. The B-17 bomb bay was short, equally wide - twice and tall. It too could carry the 4,000 pound MC bomb internally. Four of them, two on either side. ( Bomb about 3,800 pounds actual, or load <16,000 pounds.) Or it could carry eight 2,000 pounder MC bombs, four on either side. ( >16,000 pounds.), But to get to 17,600 pounds that you see in all the reference books, it had to load eleven 1,600 pound Armor Piercing bombs inside the two bays for 17,600 pounds of bombs. This was facilitated by the four bomb racks that were as tall as the entire depth of the fuselage. The same racks were doubled in the B-24, with four racks in each of the two bomb bays. These four racks could in theory, carry 38 individual 250 pound MC Bombs, or 34, 440 pound Incendiary cluster bombs! ( Because the Lanc only had 12 or 14 shackles, it could only carry 12, or 14 bombs, hence the British preference for larger bombs.) Total bomb load was reduced to meet range and altitude requirements!
6. Statistically, more smaller bombs are better at destroying most targets. The blast over pressure is a CUBE ROOT function, so that a bomb eight times as heavy is required to do twice as much damage. Also, more bombs mean more chances to have a direct hit which is infinitely preferable to a miss! Bomb fragment size and range is equal for all MC bombs because the fragments loose velocity so quickly.
7. Because the American Missions were required to fly between 25-30K' to avoid flak, their bomb loads were much less on average than those of the Lancaster. So it was tactics that determined the relative weight of bombs they would carry on average during the war, not aircraft performance!
8. The B-17 was superior to the Lancaster in construction technology, engine installation and aerodynamic performance! The B-24 was superior to the B-17 aerodynamically, but not structurally. You pays your money and takes your choice!

45-Shooter 8th Mar 2012 23:42

PS. One last point.
 
B-17s dropped about 32,000 more tons of bombs than Lancasters durring the war, while flying for fewer months of service. Their availibility rate was some multiple of the Lancs and they flew more long missions as a fraction of their total, to boot.

Load Toad 9th Mar 2012 07:17

Where is your source for that info?

ZH875 9th Mar 2012 08:42

Considering that there were some 12,731 B17s and 7377 Lancaster built, and that the B17 first flew in 1935 compared to the Lancs first flight in 1941, the B17 had many more years to get it operating correctly.

The B17 entered service in April 1938, before the war had begun The Lancaster entered service in Feb 42, not long after America joined in.

B17's dropped 640,000 tons compared to the Lancasters 608,612 tons, an average of 50 tons per B17 and 82.5 tons per Lancaster.

Richard Woods 9th Mar 2012 09:31

Counter arguments
 
45 Shooter,

To addresss your points....

1. Complete info on Lancaster bomb bay size, and loads can be found here:

Bomb Loads

I'd be interested to see what you can come up with for the B-17 in terms of loads carried and versatility. The 8000lb bomb was the one that prompted Lancaster bomb door modification, to the interior profile. Bulged doors came later.

2. Averages... why? We know every aircraft theoretically could carry max bombload, but in reality it is dictated by target and task. An average of the tonnage dropped doesn't really mean much, especially when you think that there were significantly more B17s built than Lancasters. At peak there were 4000 B17's on USAAF inventory during 1944, which is more than total Lancaster losses for the war. The maths also doesn't work unless you can verify that every one of those 156,000 sorties was a bombing one.

Regarding armour and removal - the Lancaster's armour was minimal to start with, with the pilots seat having pretty much the only armour plate. Similarly, very few Lancasters had their armaments removed, this being something done to the 'special' aircraft or occasionally the Pathfinders.

3. You're using averages again. Some missions, (Augsburg, Dams raid) were done at significantly less than the service ceiling of the Lancaster - which is listed at 24,500 feet. To get that ceiling and retain its range it would have likely been required to carry about half the load, putting it in B17 territory.

Or maybe not - seeing as the Lanc could carry the 22,000lb 'Grand Slam' up to 15,000 feet to a range of 1500 miles. The standard B17's range on a normal maximum bombload of 11,000lbs is quoted as 1100 miles...

The Tirpitz missions required an excessive range and bombload from the Lancaster, in order to get to Tromso, Norway and back. The RAF did the unthinkable, and removed the mid-upper turrets of the aircraft, and installed overload fuel tanks in the fuselage. There was no protection afforded by flying at night either as the raids were conducted in daylight.

4. Suggest further research for you into the P51 Mustang and its engine. Also look to the Merlin's use in the high altitude PR versions of Mosquito and Spitfire aircraft and the engine's post war use in the Avro Lancastrian, and particularly the Canadair North Star. The North Star's ceiling was 36,000feet. Inefficient, you say?

5. Refer to the bomb loading diagram link above. Just because there are 14 positions for standard carriers doesn't mean that is all you can fit in the bomb bay.

The 17,600lb you refer to the B17 carrying can't be done internally, it is carried off external underwing racks. I wonder how that stacks up against the normal short range of 1100 miles? Not good I'll bet.

I'm not going to bother with the B-24 as its theoretical maximum bomb load was 12,800 lb.

6. Precision bombing vs area. However the RAF (Lancaster..) attacks on submarine pens, tunnels, viaducts, and capital ships suggest that sometimes its not all about how many you can get on target.

7. Agreed. Range, Payload, Altitude. You can't have them all. However, some are better than others. ;)

8. The basic airframe design originated as the Manchester in 1939 and was designed to be strong enough to be catapult launched. The bomb bay was strong enough to hold 22,000lbs, comfortably.

The basic wing design in itself served in:

Avro Manchester
Avro Lancaster (extended by respacing wing ribs)
Avro York
Avro Lancastrian
Avro Lincoln - (extended from wingtip joint hereon)
Avro Tudor
Avro Ashton
AWA Argosy
Avro Shackleton

From 25 July 1939, to 07 July 1991 in RAF service. And before anybody says that there really isn't that much Lancaster by the time you get to the Shackleton, the drawings do say otherwise.

I'm intrigued to know how a neat engine installation that was a self contained 'power egg' is less superior to a setup that has various parts of its supercharger and oil cooler systems buried inside the wings.


Regards,

Rich

Brewster Buffalo 9th Mar 2012 21:39


Statistically, more smaller bombs are better at destroying most targets.
The post war US Strategic Bombing Survey came to the conclusion that."..the small bombs carried by the B-17s and B-24s might destroy a factory but not the precious machine tools within" So you may have got more hits with a greater number of small bombs but caused less damage..

45-Shooter 10th Mar 2012 01:01

From Wiki;

Of the 1.5 million tons of bombs dropped on Germany by U.S. aircraft, 640,000 tons were dropped from B-17s.[8]

On 30 May 1942, between 0047 and 0225 hours, in Operation Millennium 1,046 bombers dropped over 2,000 tons of high explosive and incendiaries on the medieval town of Cologne, and the resulting fires burned it from end to end. The devastation was nearly total. The fires could be seen 600 miles away at an altitude of 20,000 feet. Some 3,300 houses were destroyed, and 10,000 were damaged. 12,000 separate fires raged destroying 36 factories, damaging 270 more, and leaving 45,000 people with nowhere to live or to work. Only 384 civilians and 85 soldiers were killed, but thousands evacuated the city. Bomber Command lost 40 bombers.

From the USAAF Strategic Bombing Survey, by way of Ray Wagner on page 133, table 7;
B-17 MISSIONS = 291,508, BOMBS DROPPED = 640,036 TONS.
That is 4,391 pounds per mission, or about 56% per mission of the Lancaster's average!

45-Shooter 10th Mar 2012 01:21

All of that is true, as far as it goes.
 
But it fails to tell the entire story. The B-17 did not serve in Europe in numbers until long after the Lanc. ( First flight in Jan-'41, Service in Oct-41, 1st mass mission in Dec-41) (1st combat ready B-17E in Sept-41, 1st large mission in May-42.) At the introduction of the first full B-17E in to squadron service, there were almost two thousand Lancs delivered for service. The first B-17 variant in numbers like the Lancaster had in 1942 was the B-17F, only 3,400 built. By May 1943, the B-17G, the definitive version started to see squadron service in late 1943.
Finally, because B-17s were also kept in the states, sent to the PTO and North Africa, there were never quite as many B-17s in England as Lancasters'. More Lancs for more months equals fewer missions because of serviceability issues.

Load Toad 10th Mar 2012 01:36

With all that how do you explain they dropped soooo many bombs!

Nb. As if dropping numbers of bombs alone was the whole story anyway.

45-Shooter 10th Mar 2012 02:17

Neat web site and some good info, but still short.
 
Counter arguments
45 Shooter,

To addresss your points....

1. Complete info on Lancaster bomb bay size, and loads can be found here:

Bomb Loads
This web site does not show that the bomb bay was only 34" deep in the center and that the out side shakles could not carry any 4000 pound bomb. Note also that there were four types of 4000 pounders. The first two were so called medium case variety and less than 35" OD. The third was the first gen LC bomb and it would not fit in the Lanc's bay because it was 38" OD and shorter than the fourth version which was longer but only 34" OD. This last "Cookie" is the bomb in all the hubub is about!
I'd be interested to see what you can come up with for the B-17 in terms of loads carried and versatility. The 8000lb bomb was the one that prompted Lancaster bomb door modification, to the interior profile. Bulged doors came later.
There were also two different types of 8,000 pounders. The American version was a standard cast steel MC version and was about the same diameter as the Tallboy. It did not fit in any Lanc, except the 30-33 "Specials"! The 8,000 pounder used by the Lanc was TWO 4000 pound Cookies bolted together. It AND the 12,000 pound triple cookie fit in the Lancaster WO Bulged doors. The Bulged doors were for the American "Medium Case" bomb. The Brits let A.O. Smith cast them because there was no un-used capacity in the UK.


2. Averages... why? We know every aircraft theoretically could carry max bombload, but in reality it is dictated by target and task. An average of the tonnage dropped doesn't really mean much, especially when you think that there were significantly more B17s built than Lancasters. At peak there were 4000 B17's on USAAF inventory during 1944, which is more than total Lancaster losses for the war. The maths also doesn't work unless you can verify that every one of those 156,000 sorties was a bombing one.

Except that those 4,000 planes were scattered over four theaters. The averages are important because they highlight the availibility differances.

Regarding armour and removal - the Lancaster's armour was minimal to start with, with the pilots seat having pretty much the only armour plate. Similarly, very few Lancasters had their armaments removed, this being something done to the 'special' aircraft or occasionally the Pathfinders.

Wrong again; The tail gunner had both seat armor and BP Glass and shield, the pilot, co-pilot and bombardier also had BP Glass. The tanks were fitted with SS bags and the engines had RC plates over the oil tank and gear case. All in all, just over half a tonne total. Almost all Lancasters had the lower ventral gun poss removed, most had the top turret removed along with it's armor glass starting when they chose to go to night bombing. The average Lanc had 800 pounds of armor removed.

3. You're using averages again. Some missions, (Augsburg, Dams raid) were done at significantly less than the service ceiling of the Lancaster - which is listed at 24,500 feet. To get that ceiling and retain its range it would have likely been required to carry about half the load, putting it in B17 territory.

I pointed this out in my original post! IF they had been required to bomb in day light, at 24,000' the bomb load and range would be greatly reduced! To less than half of the AVERAGE!

Or maybe not - seeing as the Lanc could carry the 22,000lb 'Grand Slam' up to 15,000 feet to a range of 1500 miles. The standard B17's range on a normal maximum bombload of 11,000lbs is quoted as 1100 miles...

The Tirpitz missions required an excessive range and bombload from the Lancaster, in order to get to Tromso, Norway and back. The RAF did the unthinkable, and removed the mid-upper turrets of the aircraft, and installed overload fuel tanks in the fuselage. There was no protection afforded by flying at night either as the raids were conducted in daylight.

And we should judge the 8,000 by what thw 33 did? Right!

4. Suggest further research for you into the P51 Mustang and its engine. Also look to the Merlin's use in the high altitude PR versions of Mosquito and Spitfire aircraft and the engine's post war use in the Avro Lancastrian, and particularly the Canadair North Star. The North Star's ceiling was 36,000feet. Inefficient, you say?

And which version of the Lancaster used the equivilant two stage, large wheel Merlin engine? See Wiki;

Merlin XX (RM 3SM)
1,480 hp (1,105 kW) at 3,000 rpm at 6,000 ft (1,830 m); two-speed supercharger; boost pressure of up to +14 psi; Used in Hurricane Mk.II, Beaufighter Mk.II, s, Halifax Mk.II and Lancaster Mk.I bombers, and in the Spitfire Mk.III prototypes (N3297 & W3237).[77] First production Merlin XX, 4 July 1940.[18][nb 13] V-1650-1: 1,390 hp (1,040 kW); Based on Merlin 28, used in the LancasterNote that both of these engines are two speed single blower engines!

5. Refer to the bomb loading diagram link above. Just because there are 14 positions for standard carriers doesn't mean that is all you can fit in the bomb bay.

There are 15 possitions, only 14 of which are usable at any one time. But that is only later versions, because the early types only had 12 shakels and could not cary any 4000 pound bomb with the doors on at that time!

The 17,600lb you refer to the B17 carrying can't be done internally, it is carried off external underwing racks. I wonder how that stacks up against the normal short range of 1100 miles? Not good I'll bet.

Again you are mistaken, as eleven 1,600 pound armor piercing bombs fit entirely inside the bay with the doors closed. They are not nearly as large in diamiter as a 1,000 pound GP bomb. Can you list the external load that yealds the 17,600 pounds mentioned?

I'm not going to bother with the B-24 as its theoretical maximum bomb load was 12,800 lb.

This is limited by weight and balance considerations, not load. If they wanted, it could load and fly with almost 16,000 pounds up, in the form of 4X4,000 pound GP bombs.

6. Precision bombing vs area. However the RAF (Lancaster..) attacks on submarine pens, tunnels, viaducts, and capital ships suggest that sometimes its not all about how many you can get on target.

If you discount all the day light missions, then the RAF states that less than 50% of the bombs landed inside the city limits. All bombs that landed out side the city were zero effectiveness. When the Americans claimed that 2% of bombs hit the targets, the other 98% still hit the city, so the AVERAGE EFFECTIVENESS was twice that of the Lanc?

7. Agreed. Range, Payload, Altitude. You can't have them all. However, some are better than others. http://images.ibsrv.net/ibsrv/res/sr...lies/wink2.gif
You are so very right about this!

8. The basic airframe design originated as the Manchester in 1939 and was designed to be strong enough to be catapult launched. The bomb bay was strong enough to hold 22,000lbs, comfortably.

No! The fuse required significant re-enforcement before it could cary the 12,000 pound tallboy, Up Keep bouncing bomb AND significantly more re-enforcement to carry the Grand Slam.

I'm intrigued to know how a neat engine installation that was a self contained 'power egg' is less superior to a setup that has various parts of its supercharger and oil cooler systems buried inside the wings.

The Lanc's engines were single stage, two speed blowered, WO Turbo-charger! While it was simple, there is no way to compaire it to the Supercharged with turbo-blower used in the American planes.

Regards,

Stewart.

45-Shooter 10th Mar 2012 02:28

Quote:
Statistically, more smaller bombs are better at destroying most targets.
The post war US Strategic Bombing Survey came to the conclusion that."..the small bombs carried by the B-17s and B-24s might destroy a factory but not the precious machine tools within" So you may have got more hits with a greater number of small bombs but caused less damage..

The above quote is taken out of context. If you read the entire volume, out of ~208 in the entire SB Survey, IIRC, it states "that in general, the smaller bomb must land much closer to the target to destroy it." The source of the above quote.
But if you read the rest of the PP, it states that hitting the factory with 25-100 each 500 pound bombs would destroy more equipment than the 2-3 hits that result from dropping larger bombs from many more aircraft dispersed over a much larger chunk of sky. Further more "The best results were achieved by dropping the most large bombs from the fewest B-29s that can fit over the target zone."

longer ron 10th Mar 2012 02:42


most had the top turret removed along with it's armor glass starting when they chose to go to night bombing.
I don't know where you got that info from but I suggest that you look at the hundreds of pictures of main force Lancs which indeed did have the mid upper fitted.
The Lanc was not subject to much weight related modification when in service.
The merlin engined Halifax was the a/c which was stripped out to get bombing altitude.
So to recap...the main force Lancs had the mid upper as standard...the mid upper was only removed for certain specific squadrons/tasks

I would also suggest that using Wiki as a primary source is unwise on an aviation forum,it is full of erm 'inaccuracies'

rgds LR

longer ron 10th Mar 2012 02:57


Wrong again; The tail gunner had both seat armor and BP Glass and shield, the pilot, co-pilot and bombardier also had BP Glass. The tanks were fitted with SS bags and the engines had RC plates over the oil tank and gear case. All in all, just over half a tonne total. Almost all Lancasters had the lower ventral gun poss removed, most had the top turret removed along with it's armor glass starting when they chose to go to night bombing. The average Lanc had 800 pounds of armor removed.
This is the complete paragraph which I quoted from in my previous post...

Re the tail gunners turret...many of the experienced tail gunners removed large areas of turret glazing,but this was not weight saving !It was to cut down on reflections etc and thereby improving night vision.

rgds LR

45-Shooter 10th Mar 2012 03:13

Argueing from the specific to the general, or vice-verse
 
Hundreds of pics out of thousands built? according to the RAF's web site, "Most Lancasters had the Mid-upper turret and most other weapons removed for night bombing. Many going with only the tail gunner to keep watch for night fighters"
A tonne of guns, armor and ammo removed, plus the surface area, form drag and induced drag related to it, all gone. What kind of contribution do you think it made to total performance.
Finally, the Americans and Brits figured range by two vastly different systems. The Americans figured 40-45% of range to bomb drop, including all the course changes. The Brits printed the total range WO stating that the bombs were dropped at some point less than half that distance to the target.

45-Shooter 10th Mar 2012 03:15

And that changes things how?
 
The RAF states that most Lancs carried only the tail gunner on night missions. Why would they leave with unmanned, but installed weapons?


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