Questions about B-29 operational range, VVS, VVS intercept capability if Operation Unthinkable happen.

[Thumpalumpacus]

The RAF bases in England, visited by "Hobo Queen" (41-36963) in 1944, were:
RAF St. Mawgen
RAF Horsham St. Faith
RAF Bassingbourn
RAF Knettishall
RAF Glatton

So there seems to have been larger airfields in the UK capable of handling a B-29, especially in light of the 1946 "deep penetration" bomb tests conducted by B-29s (and B-17s) against the U-Boat pens at Heligoland.
Some of the bombs used in the tests were as large as the 22,000 "Amazon" bomb. So an adequate airfield for overload TO did exist.

How far are those bases from Soviet supply nodes etc? And how many aircraft as large as B-29s could they support apiece? In short, would they be viable operationally rather than just a pit-stop for a tour?

I think even with their long range B-29s would have to be based ConEur.

 

[GrauGeist]

The problem with being based in the continent, is that the bombers and their support would be within Soviet strike range with short notice.

The exception *may* be Italy, who did have some large airfields for their bombers, but I am not sure how well they fared after the Allies mauled them in the push "up the boot".

If I remember right, there was a large airfield at Brindisi that was used for maritime strikes and transport across the Med which was substantial.

Also considering that this offensive would not be by air alone - if Allied forces were able to push Red Army elements back far enough, then yes, the Superforts could then safely use former several Luftwaffe bases which were considerably large and very well built.

In regards to an earlier post about Soviet factory locations: Germany did have good Intel on their industrial locations - perhaps go over the last (latest) documents or consult with former RLM intelligence officers to get an idea of locale, and start there.

 

[Thumpalumpacus]

The problem with being based in the continent, is that the bombers and their support would be within Soviet strike range with short notice.

That's not a problem unknown to the Allies. It's war. That's why there's radar and fighters and AA and yes, you will take losses. But if you base heavies back a couple of hundred miles, which is not only sensible but also practiced in all theaters, it's pretty hard for Soviets mediums to get to them -- especially without fighter escort. Henderson Field and Saipan showed resilience in the face of counterattacks.

 

[ThomasP]

re

Answer was the P-82 Twin Mustang, originally designed for 2000 mile escort missions of B-29s,

If my information is correct, the P-82 maximum combat radius for VLR escort missions was ~1000 miles at 25,000 ft outbound with maximum usable fuel. Any significantly greater distance would be a one-way mission.

Unfortunately, I do not have the SACs or CSs for the P-82 so cannot use the exact comparison to the P-47N & P-51H.

Maybe someone else has the P-82/F-82 SACs or CSs and could post them here?

 

[special ed]

Don't forget, if this fantasy conflict continued just after V-E day, or maybe later after V-J day, most of our assembly lines would continue producing materials, including the B-32.

 

[EwenS]

The RAF bases in England, visited by "Hobo Queen" (41-36963) in 1944, were:
RAF St. Mawgen

St Mawgan. Located in Cornwall, about as far west in the UK as you can get, away from the scene of the action being proposed. Constructed from Feb 1942 to mid-1944 as a replacement for Trebelzue, which was eventually incorporated into its perimeter and used for parking arriving aircraft. Used by the USAAF as a transit airfield for aircraft arriving / departing the UK from mid-1943, hence why it was the first airfield visited by Hobo Queen. The USAAF completed a runway extension in May 1944 to 8,229ft on one of the runways.

The other airfields were all built to Air Ministry Class A standards.

RAF Horsham St. Faith

Now Norwich Airport. Longest WW2 runway 5,487 ft. Not much longer today.

RAF Bassingbourn

Longest WW2 runway 5,484ft

RAF Knettishall

longest WW2 runway 5,487ft

RAF Glatton

Longest WW2 runway 5,487ft

So there seems to have been larger airfields in the UK capable of handling a B-29, especially in light of the 1946 "deep penetration" bomb tests conducted by B-29s (and B-17s) against the U-Boat pens at Heligoland.
Some of the bombs used in the tests were as large as the 22,000 "Amazon" bomb as well as the Tallboy (both U.S. and British versions), Grand Slam (both U.S. and British versions), Disney and others.

Hobo Queen was one of fourteen YB-29 service test aircraft. It was sent over to Britain on what was little more than a propaganda tour. It arrived at St Mawgan on 11 March 1944 and left again in early April. It had no need to operate in an operational configuration, let alone at the excessive weights used by Twentieth AF B-29 operating from the Marianas. So no need for the long runways that were needed in the Pacific. Now try to bomb the USSR and aircraft weight and the necessary runway lengths goes up.

"During its short stay in the U.K. it was known to have visited RAF Horsham St. Faith near Norwich, RAF Bassingbourn on the 8th March, RAF Knettishall and RAF Glatton on 11th March before its final departure from RAF St. Mawgan to India in April that year. The route took the YB-29 to Marrakech, Cairo (2nd April), Karachi (5th Apr) finally arriving at Kharagpur, India, on 6th Apr 1944 . Once here, it was assigned to the 769th Bomb Squadron, 462nd Bomb Group who were then based at Piardoba in India, where it was modified as a tanker to ferry fuel over 'the Hump'. The YB-29, the only test model to fly overseas, gave a successful service, eventually being declared war weary and returned to the United States, its eventual fate being unknown, presumably, like many war weary models, the aircraft was scrapped."​

As for 1946, three B-29 came over to participate in Operation Ruby. They were based at Marham, Norfolk (see below)​

"Although B-29s were initially considered for the European theatre none operated from British soil until after the wars end, when a joint British and American operation, Project 'Ruby'*5​, investigated deep penetration bombs against reinforced concrete structures. Three B-29s were prepared in the United States along with four B-17s and a select detachment of admin, maintenance, technical staff and air crew, who arrived at RAF Marham, Norfolk, on March 15th 1946. Initial plans were to test a series of bombs on the submarine assembly plant at Farge, but due to the close proximity of housing and an electricity plant, the U-boat shelter at Heligoland was used instead. The bombing trials began on March 25th by which time an original three B-17s from RAF Mildenhall had also joined the group.

A number of both American and British bombs were tested in the trials:

• The US 22,000lb. 'Amazon' bomb
• The US rocket assisted 4,500lb. 'Disney' bomb (used by B-17s in the latter stages of the war)
• The 4,500lb. 'Disney' bomb without rocket assistance
• The American 22,000lb. fabricated 'Grand Slam' (designated T14)
• The American 12,000lb. fabricated 'Tall Boy' (designated T10)
• The British 12,000lb, 'Tall Boy'
• The British 2,000lb. Armour Piercing bomb
• The inert loaded 2,000lb. SAP (M103) bomb
• The Picratol filled 2,000lb. SAP (M103) bomb
• The 1,650lb. Model bomb

The results of the trials were quite conclusive, none of these bombs in their current form, were capable of penetrating the 23 ft thick concrete of the Farge roof, and therefore, all would need adapting, redeveloping or redesigning if such operations were to be carried out again."

Again the range involved was nowhere near what is being considered in this thread. The target, the Valentin U-boat construction bunker, lay on the Weser River between Bremerhaven & Bremen close to the German North Sea coast.

As early as July 1943 a requirement for 12 Very Heavy bomber bases with c9,000ft runways was envisaged to allow deployment of "very heavy bombers" like the B-29 and Vickers Windsor. Marham & Sculthorpe & Lakenheath were the first to be upgraded. They closed between March & May 1944 and work did not allow their reopening until 1946. All got runways 8,229ft long and 273ft wide. The great width is probably related to the Windsor which had 4 separate wheels, one under each engine, giving it a much wider track track than other aircraft. A number of other airfields were selected for the upgrade but none happened in this timescale. It was these 3 bases that Strategic Air Command B-29 units occupied when they arrived in the UK in 1948. New bases were then developed for them at Brize Norton, Upper Heyford, Greenham Common & Fairford.​

 

[Reluctant Poster]

St Mawgan. Located in Cornwall, about as far west in the UK as you can get, away from the scene of the action being proposed. Constructed from Feb 1942 to mid-1944 as a replacement for Trebelzue, which was eventually incorporated into its perimeter and used for parking arriving aircraft. Used by the USAAF as a transit airfield for aircraft arriving / departing the UK from mid-1943, hence why it was the first airfield visited by Hobo Queen. The USAAF completed a runway extension in May 1944 to 8,229ft on one of the runways.

The other airfields were all built to Air Ministry Class A standards.

Now Norwich Airport. Longest WW2 runway 5,487 ft. Not much longer today.

Longest WW2 runway 5,484ft

longest WW2 runway 5,487ft

Longest WW2 runway 5,487ft

Hobo Queen was one of fourteen YB-29 service test aircraft. It was sent over to Britain on what was little more than a propaganda tour. It arrived at St Mawgan on 11 March 1944 and left again in early April. It had no need to operate in an operational configuration, let alone at the excessive weights used by Twentieth AF B-29 operating from the Marianas. So no need for the long runways that were needed in the Pacific. Now try to bomb the USSR and aircraft weight and the necessary runway lengths goes up.

"During its short stay in the U.K. it was known to have visited RAF Horsham St. Faith near Norwich, RAF Bassingbourn on the 8th March, RAF Knettishall and RAF Glatton on 11th March before its final departure from RAF St. Mawgan to India in April that year. The route took the YB-29 to Marrakech, Cairo (2nd April), Karachi (5th Apr) finally arriving at Kharagpur, India, on 6th Apr 1944 . Once here, it was assigned to the 769th Bomb Squadron, 462nd Bomb Group who were then based at Piardoba in India, where it was modified as a tanker to ferry fuel over 'the Hump'. The YB-29, the only test model to fly overseas, gave a successful service, eventually being declared war weary and returned to the United States, its eventual fate being unknown, presumably, like many war weary models, the aircraft was scrapped."​

As for 1946, three B-29 came over to participate in Operation Ruby. They were based at Marham, Norfolk (see below)​

"Although B-29s were initially considered for the European theatre none operated from British soil until after the wars end, when a joint British and American operation, Project 'Ruby'*5​, investigated deep penetration bombs against reinforced concrete structures. Three B-29s were prepared in the United States along with four B-17s and a select detachment of admin, maintenance, technical staff and air crew, who arrived at RAF Marham, Norfolk, on March 15th 1946. Initial plans were to test a series of bombs on the submarine assembly plant at Farge, but due to the close proximity of housing and an electricity plant, the U-boat shelter at Heligoland was used instead. The bombing trials began on March 25th by which time an original three B-17s from RAF Mildenhall had also joined the group.

A number of both American and British bombs were tested in the trials:

• The US 22,000lb. 'Amazon' bomb
• The US rocket assisted 4,500lb. 'Disney' bomb (used by B-17s in the latter stages of the war)
• The 4,500lb. 'Disney' bomb without rocket assistance
• The American 22,000lb. fabricated 'Grand Slam' (designated T14)
• The American 12,000lb. fabricated 'Tall Boy' (designated T10)
• The British 12,000lb, 'Tall Boy'
• The British 2,000lb. Armour Piercing bomb
• The inert loaded 2,000lb. SAP (M103) bomb
• The Picratol filled 2,000lb. SAP (M103) bomb
• The 1,650lb. Model bomb

The results of the trials were quite conclusive, none of these bombs in their current form, were capable of penetrating the 23 ft thick concrete of the Farge roof, and therefore, all would need adapting, redeveloping or redesigning if such operations were to be carried out again."

Again the range involved was nowhere near what is being considered in this thread. The target, the Valentin U-boat construction bunker, lay on the Weser River between Bremerhaven & Bremen close to the German North Sea coast.

As early as July 1943 a requirement for 12 Very Heavy bomber bases with c9,000ft runways was envisaged to allow deployment of "very heavy bombers" like the B-29 and Vickers Windsor. Marham & Sculthorpe & Lakenheath were the first to be upgraded. They closed between March & May 1944 and work did not allow their reopening until 1946. All got runways 8,229ft long and 273ft wide. The great width is probably related to the Windsor which had 4 separate wheels, one under each engine, giving it a much wider track track than other aircraft. A number of other airfields were selected for the upgrade but none happened in this timescale. It was these 3 bases that Strategic Air Command B-29 units occupied when they arrived in the UK in 1948. New bases were then developed for them at Brize Norton, Upper Heyford, Greenham Common & Fairford.​

The Disney bomb was British.
What is the The 1,650lb. Model bomb?

 

[MIflyer]

The Disney bomb was British.

What a Mickey Mouse nuclear weapons program!

 

[marathag]

Just because it's possible doesn't mean it's an acceptable solution for widespread use. Just a guess on my part, but I'd assume that having to rely on JATO to launch heavy laden long range bombing missions from short airstrips with many aircraft introduces too much risk of catastrophic failures. The last thing you'd want is to have a takeoff malfunction with an overloaded B-29 that would probably result in a crash with the total loss of the plane and aircrew, and severe injury anyone and anything within the surface danger area. It would be considerably worse if the crash involved atomic munitions.

JATOs on B47s was widespread, and those carried megaton class bombs, not 15kt bombs
reliable enough to be built in

(18) 1000 pound thrust bottles total.
for regular use

after the B-47E, JATO was more optional, and used an external rack system as engine power(with water injection)increased

that were jettisoned after take-off
JATO reduced the take-off run by 2500-3000 feet

 

[marathag]

So there seems to have been larger airfields in the UK capable of handling a B-29, especially in light of the 1946 "deep penetration" bomb tests conducted by B-29s (and B-17s) against the U-Boat pens at Heligoland.

Seems a number of airfields postwar were also improved to handle the Bristol Brabazon at nearly 300,000 pounds: that's B-36 weight class, more than twice the B-29, before that monster had first flight in 1949

 

[EwenS]

Seems a number of airfields postwar were also improved to handle the Bristol Brabazon at nearly 300,000 pounds: that's B-36 weight class, more than twice the B-29, before that monster had first flight in 1949

I'd forgotten about the Brabazon.

It was originally intended to build this aircraft at Bristol Aircraft's Weston-super-Mare factory. But the ground there would not support the required strengthend runway. So production had to be transferred to the Filton site. a huge new assembly hangar, still in use today, had to be built to accomodate it as well as a new runway of a similar size to Marham as noted in my last post. The new assembly hangar & runway cost £5.5m. Lightly loaded the Brabazon needed only 1,500ft of runway and took of at 85 knots. In WW2 Filton's longest runway was only 4,116ft long.

Construction of a new Heathrow airport began in early 1944 on the site of the pre-war grass Great West Aerodrome used by Fairey Aviation, and virtually obliberating all of it in the process. Heathrow officially opened on 25 March 1946 but much of the passenger processing was still carried out in tents as it was far from complete. It was also built to the new standards.

 

[33k in the air]

According to the Standard Aircraft Characteristics for the B-29A, with 10,000 lbs of bombs and a high altitude mission profile (cruising at 20,000 feet, climbing to reach 30,000 feet thirty minutes prior to bomb release), it had a combat radius of 1,799 miles (1,563 nm). London to Moscow is about 1,550 miles direct, so the B-29A could reach some 250 miles past that from southeast Britain.

If Unthinkable is delayed to late 1948, the B-50A and B-36A become available in limited numbers.

According to the SAC for the B-50A, with 10,000 lbs of bombs and a high altitude mission profile (cruising at 20,000 feet, climbing to reach 30,000 feet thirty minutes prior to bomb release), it had a combat radius of 2,288 miles (1,988 nm). According to B-36A SAC, with 10,000 lbs of bombs and a high altitude mission profile (cruising at 25,000 feet, climbing to reach 40,000 feet 1,150 miles from the target), it had a combat radius of 2,860 miles (2,485 nm).

Regarding the P-82, its SAC is not online as far as I'm aware. The only reference to its combat radius I've come across is one listed in the Encyclopedia of US Air Force Aircraft and Missile Systems. It gives a combat radius figure at sea level of 1,123 miles (976 nm) for the F-82E. There is no description of the parameters involved.

 

[bf109xxl]

That is what all the strategic bombing aficionados said. You bomb a factory. Either they fix it in a week or two, or they move it to a new location.

Do you think that in the USSR factories were moved or fixed by magic?! The evacuation of industry in 1941 was made most often either to already built factories, or to pre-prepared sites. And this led to a drastic reduction in the output of military products. The Soviets had little opportunity to disperse production to small factories for many reasons.
How many synthetic fuel plants were moved/put into operation in the Reich after the systematic bombing of factories in this industry began? The question is again rhetorical.

 

[bf109xxl]

I suspect the light armament of most Soviet fighters would not have been up to the task, even if their airframes could perform well at those altitudes.

Serial production of the NS-23 gun with a powerful shell was started in 1944. It would be enough to shoot down any bomber of that time.

 

[bf109xxl]

Someone suggested using Norway as a base. Fine but remember a few things:-
1. The few airfields that existed were on the western coast and hemmed in by steep mountain ranges to the east.
2. Your journeys to /from targets around the Baltic or in Northern USSR mean flying around neutral Swedish airspace, unless they join on our side. A neutral Sweden can be expected to seek to protect its airspace.
3. Again runway lengths. A quick look at Bodo & Bardufoss in the north (both main Luftwaffe bases) had runways only 4-6,000ft long at the end of WW2.

Taking into account the quantity and quality of Western Allied engineering equipment, the extension of the Norwegian airfield runways (two airfields would be sufficient) would hardly take more than a month. Sweden would unlikely keep its neutrality, and there was no point in it anymore. But it would require a powerful air defense of these airfields, which is also quite possible for the Western Allies.
Even a few dozen German bombers, which managed to reach the target, inflicted serious damages to the factories on the Volga - with inferior bomb sights and low bomb load, at altitudes of 4-5 km, where the Soviet 85-mm AAA was effective.
In 1945, the Soviets had no effective weapons against the B-29s. Even a relatively small number of these bombers had a good chance to inflict critical damage on Soviet industry. In general, the Soviets had no such weapons until 1948, and Soviet air defense remained penetrable until about the late 1950s. Only the MiG-15 became a real threat to Western strategic bombers.

 

[Thumpalumpacus]

Serial production of the NS-23 gun with a powerful shell was started in 1944. It would be enough to shoot down any bomber of that time.

How many carried by what fighters? We're at a point that it's not so much about weapons as it is about weapons systems. Can the fighters get them up that high effectively? Can they fight through escorts? How many rounds -- how much trigger-time -- do VVS pilots have? Do they have the radar network to put the fighters into the right airspace? How many fighters are flying this defense?

 

[bf109xxl]

How many carried by what fighters? We're at a point that it's not so much about weapons as it is about weapons systems. Can the fighters get them up that high effectively? Can they fight through escorts? How many rounds -- how much trigger-time -- do VVS pilots have? Do they have the radar network to put the fighters into the right airspace? How many fighters are flying this defense?

The cannon was tested from November 1943 to May 1944 on the Yak-9, and after the war 1xHC-23+2xB-20 became the standard armament of the Yak-s - it was quite sufficient. The synchronized version for La was also quickly put into mass production. I think that if there was a big demand, production could be significantly increased already in 1945.
I merely pointed out that the Soviets had a quite adequate cannon. The ammunition was not large, but it was not decisive if there was no possibility to make a second attack on the enemy (the high effectiveness of the 23mm shell should also be taken into account). How successful the fight with an escort would be is a difficult question for me. I think that certain regiments with experienced veterans could be a serious threat, but not at altitudes of 8-9 km, where even they would be hardly able to fight on an equal footing with the Mustangs - the advantage of the latter in flight performance became too great.

 

[Thumpalumpacus]

The cannon was tested from November 1943 to May 1944 on the Yak-9, and after the war 1xHC-23+2xB-20 became the standard armament of the Yak-s - it was quite sufficient. The synchronized version for La was also quickly put into mass production. I think that if there was a big demand, production could be significantly increased already in 1945.
I merely pointed out that the Soviets had a quite adequate cannon. The ammunition was not large, but it was not decisive if there was no possibility to make a second attack on the enemy (the high effectiveness of the 23mm shell should also be taken into account). How successful the fight with an escort would be is a difficult question for me. I think that certain regiments with experienced veterans could be a serious threat, but not at altitudes of 8-9 km, where even they would be hardly able to fight on an equal footing with the Mustangs - the advantage of the latter in flight performance became too great.

Right -- there's a lot more to weapons than just the weapons.

I think everyone had adequate cannons to knock down heavy bombers by 1945. The point is that if those cannon can't get lofted to where the bombers are, and laid onto target, they may as well be pogo-sticks.

The Soviets have zero-point-zero experience dealing with 1000-bomber raids, defensively and doctrinally.

 

[Dimlee]

If "Unthinkable" begins in the summer of 1945 as it was in the initial plan, then:

1. The USSR could have launched the Operation Osoaviakhim earlier. Jägernotprogramm in the Soviet style? The industry is less advanced compared to Germany but relocated engineers will share all negative and positive experiences and the spies and useful idiots in the Allied countries will be mobilised to steal everything that could help.

2. Iran will certainly become a battlefield and a heavily contested one. Both sides will target the adversary's oil industry.

 

[bf109xxl]

Operation Osoaviakhim

A perfect illustration of what I said about the lack of highly qualified personnel in the USSR.

2. Iran will certainly become a battlefield and a heavily contested one. Both sides will target the adversary's oil industry.

I'm not sure about Iran - I think the Soviets would have huge logistical difficulties there with Allied air superiority, but Baku can be bombed from Iraq as well. And even from Egypt, if I'm not mistaken.