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

[GrauGeist]

A friend who was a tail gunner on B-29s in Korea said he was terrified of the MiG-15. The tracking system of the 29 could not track the 15 as the attacks were faster than the onboard system capability. He never mentioned any prop plane attacks. In fact, when discussing missions, he would get that far away look and stop talking.

That was the issue with the B-17s and B-24s during WWII, when attacked by Me262s.

Their best chance to down an Me262 (just as with the B-29 and MiG-15s) was if attacked from behind, but that was a small window of opportunity because once those four 30mm cannon opened up, things were getting ugly fast.

 

[Thumpalumpacus]

That's right. Actually, it was a rhetorical question on my part - the effectiveness of the best Soviet piston-engined fighters against the B-29 was extremely low. I suspect it would be insufficient against the B-17/-24/Lancs as well, but in this case a fighter escort would be necessary.

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.

 

[ThomasP]

re

Yes, P-47N and P-51D and H would be most likely. P-47N in particular was designed to escort the B-29 during the entire mission.

The P-47N and P-51D/H maximum combat radius for VLR escort missions (as figured by the USAAF/USAF in their standard 1945-50 range calculations) was ~900 miles at 25,000 ft outbound with maximum usable fuel. Any significantly greater distance would be a one-way mission.

Yes? No?

 

[Dimlee]

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.

As mentioned earlier, there were bombing raids against the Soviet industry. For example, Luftwaffe operation Carmen II was mentioned earlier. Factories bombed by Ju 88s and He 111s in May-June 1943 didn't restore their output until the end of 1943, for some of them, it took even longer. And no, the "beyond Urals" industry couldn't help fill the gaps since there were unique production lines, such as tyres for artillery, etc.
Sometimes, aficionados are not wrong...

 

[Dimlee]

re


The P-47N and P-51D/H maximum combat radius for VLR escort missions (as figured by the USAAF/USAF in their standard 1945-50 range calculations) was ~900 miles at 25,000 ft outbound with maximum usable fuel. Any significantly greater distance would be a one-way mission.

Yes? No?

If so, then possible escorted raids to the USSR in Europe are:
- Norway to Leningrad, Pechenga, Murmansk. Maybe to Arkhangelsk.
- Mid East to Baku, Tbilisi, Grozny, Tuapse
and against all ports in the Baltic and Black Sea.
In Asia, most of the industry and most important ports in the Soviet Far East are within the radius of escorts - once the USAAF can get bases in Japan.

 

[marathag]

The P-47N and P-51D/H maximum combat radius for VLR escort missions (as figured by the USAAF/USAF in their standard 1945-50 range calculations) was ~900 miles at 25,000 ft outbound with maximum usable fuel. Any significantly greater distance would be a one-way mission.

Yes? No?

Answer was the P-82 Twin Mustang, originally designed for 2000 mile escort missions of B-29s, but first flight in June 1945 means they missed the War.
Then more delays with the switch from Packard built Merlins to Allison power

 

[EwenS]

A few things to remember about B-29 operations from the Marianas in 1944/45, many of which have implications for operations against the central parts of the USSR.

There were 28,329 individual aircraft sorties dispatched in 331 Missions of all types. An average of 86 aircraft per mission. Only 35 Missions exceeded 150 aircraft dispatched (although there were occasions when multiple Missions were flown on the same day/night but against different targets). Only 75 were described as "Urban Area" attacks - the firebomb raids - which tended to involve more aircraft. So few were on the scale of 8th AF Missions.

B-29s were operating out of the Marianas at TOW of up to 137,000lb, well in excess of design, including about 10,000lb of bombs. Flying lower level missions allowed a fuel reduction of only a few thousand pounds and a greater safety margin.

The airfields built in the Marianas generally had multiple parallel runways (2-4) of c8,500 ft long. Very few airfields in Europe had runways that long. Air Ministry Class A airfields had at least one runway of 6,000ft. It was only some of the Emergency Airfields (like Manston, Woodbridge & Carnaby) that had a runway of 9,000ft long. So the US Army engineers have a major job on their hands renovating and expanding European airfields to take the B-29s. The airfields in the Marianas each took about 4 months to construct, even if there was an existing Japanese airfield to base it on. The B-29 was a much heavier aircraft than those operating in Europe and that had an effect on the runway strength required.

Aircraft flew individually to a meeting point, usually some 250 short of Japan, where they met up to proceed to the target. Generally the trip north would be at lower levels or using a stepped climb, increasing altitude as the fuel burned off. Only after the meeting point would the final climb to bombing altitude be made. But if flying against targets deep in the USSR it seems to me that the climb to higher altitudes could not be stretched out, so increasing fuel burn in heavily loaded aircraft on the way out.

Iwo Jima played a hugely important part in B-29 operations but not in the way that might be imagined. Situated about half way between the Marianas & Japan it provided an emergency airfield for the B-29s from the first B-29 landing on 9 March to the end of the war. In all about 2,400 such landings took place. About 82% of those landed for fuel, with the remainder for repairs. Now we don't know how many would have been lost before reaching their home base. But what happens when that translates to operations that for the most part would be flown over enemy territory without the chance of an emergency field?

129 B-29 ditched, crashed in the sea or were abandoned by their crews over the sea. Air sea rescue operations saved 1,429 crewmen. Those ASR operations included aircraft flying from the Marianas & Iwo Jima, surface ships placed along the route and submarines near the Japanese coast, all specifically deployed for that purpose. How much of this is possible with long routes to targets deep in the USSR?

The 15th FG with P-51D moved onto Iwo Jima Airfield No 1 on 6 March 1945, followed by the 21st FG on Airfield No 2 22-24 March and 506th FG on 11 May 1945 on Airfield No 3, all with P-51D. Finally the P-47N equipped 414th FG arrived in July. It was 7 April before the first VLR mission was flown (escorting B-29s the appoximate 750 statute miles / 660 nautical miles to Tokyo). But not many of their operations were B-29 escort. Many more were fighter sweeps over Japan. As escorts they usually picked up the bombers somewhere close to the Japanese coast, allowing fuel saving on the way up.

Reconnaissance. Just how much was known in 1945/46 about where the prime targets actually were? Or is the intention simply to flatten every city in the USSR? This was also a problem with Japan in 1945, hence the development of the F-13 photo recce version of the B-29 (118 conversions made). The USSR had been a closed country for decades. In WW2 the Soviets were deeply suspicious of ousiders & monitored them all closely and restricted their movements.

So you are going to need more F-13s to cover the USSR. Or even better pushing development of the Hughes XF-11 (ff 7 July 1946) and / or the Republic XF-12 Rainbow (ff 4 Feb 1946)

Hughes XF-11 - Wikipedia

en.wikipedia.org

Republic XF-12 Rainbow - Wikipedia

en.wikipedia.org

Also weather recce. As weather patterns normally pass west to east over Europe some information would be available, but the deeper you go the more unreliable it would become. Similar issues arose over the distances to / from Japan. So diversion of B-29 for that purpose became necessary.

Atomic bombs. Production was intended to continue at an increasing rate into 1946. From Groves Memo to the Chiefs of Staff dated 30 July 1945.

. The final components of the first gun type bomb have arrived at Tinian, those of the first implosion type should leave San Francisco by airplane early on 30 July. I see no reason to change our previous readiness predictions on the first three bombs. In September, we should have three or four bombs. One of these will be made from 235 material and will have a smaller effectiveness, about two-thirds that of the test type, but by November, we should be able to bring this up to full power. There should be either four or three bombs in October, one of the lesser size. In November, there should be at least five bombs and the rate will rise to seven in December and increase decidedly in early 1946.

In fact with the end of the war production rates slowed. But there is still only the 393rd BS, 509th CG equipped with 15 Silverplate B-29s available to drop them. Any other units to be formed / converted to dropping them will require time ro train.

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.

I've posted earlier about the situation in Iran with the Soviets occupying the northern part of the country.

What is in it for Turkey allowing bases to be built on its territory? They managed to stay out of WW2 despite pressure from both sides at various times.

 

[SaparotRob]

Could B-29 bases be built on European territory and shave a couple of hundred miles off?

 

[Thumpalumpacus]

Could B-29 bases be built on European territory and shave a couple of hundred miles off?

German jet bases were noted for their long runways. Even if still not long enough for the Superfort, they would be easier to upgrade, presumably.

 

[EwenS]

German jet bases were noted for their long runways. Even if still not long enough for the Superfort, they would be easier to upgrade, presumably.

It is not just the length (and width) of runways, but their strength to take the weight of a B-29. That means deeper foundations than needed for a WW2 generation fighter, or even the size of bomber operated by the Luftwaffe. That could mean digging up the runway and relaying the entire runway on a new base.

 

[Thumpalumpacus]

It is not just the length (and width) of runways, but their strength to take the weight of a B-29. That means deeper foundations than needed for a WW2 generation fighter, or even the size of bomber operated by the Luftwaffe. That could mean digging up the runway and relaying the entire runway on a new base.

Could they not add the reinforcement layer on top of the existing runway?

 

[SaparotRob]

Also, wouldn't it be easier to build large runways in Europe than a distant coral atoll?

 

[Dimlee]

Reconnaissance. Just how much was known in 1945/46 about where the prime targets actually were? Or is the intention simply to flatten every city in the USSR?

It was mentioned by

bf109xxl

and I agree with that: most of the pre-war industry was built with the help of foreign experts from various countries, including the USA. Germans have not just locations but also detailed plans for many factories and electrical plants and when they planned Eisenhammer, the pilots knew exactly where to aim.

Also weather recce. As weather patterns normally pass west to east over Europe some information would be available, but the deeper you go the more unreliable it would become

True, however, the Luftwaffe accumulated a vast knowledge in 4 years.

Your journeys to /from targets around the Baltic or in Northern USSR mean flying around neutral Swedish airspace, unless they join on our side.

The Baltic Sea can be flown over without entering Swedish air space.

What is in it for Turkey allowing bases to be built on its territory?

Turkey joined the Allies only at the end of WWII. Dragging her into a new war would be a very difficult task, most probably.

 

[NevadaK]

re


The P-47N and P-51D/H maximum combat radius for VLR escort missions (as figured by the USAAF/USAF in their standard 1945-50 range calculations) was ~900 miles at 25,000 ft outbound with maximum usable fuel. Any significantly greater distance would be a one-way mission.

Yes? No?

Thanks, since I was going by memory I stand corrected.

 

[NevadaK]

Could they not add the reinforcement layer on top of the existing runway?

The short answer is, no. A runway or roadway's bearing capacity is largely defined by the compaction of the soil beneath it. Simply adding top material won't enhance capacity without elaborate structural design. In the end it would be faster and cheaper to tear the runway up, add compaction, and put down a new surface.

 

[marathag]

The airfields built in the Marianas generally had multiple parallel runways (2-4) of c8,500 ft long. Very few airfields in Europe had runways that long. Air Ministry Class A airfields had at least one runway of 6,000ft. It was only some of the Emergency Airfields (like Manston, Woodbridge & Carnaby) that had a runway of 9,000ft long. So the US Army engineers have a major job on their hands renovating and expanding European airfields to take the B-29s

Or the USAAF OK's the use of JATO after the Navy shown it to work earlier in 1944

so this can happen

sooner than this 1949 flight

 

[NevadaK]

Also, wouldn't it be easier to build large runways in Europe than a distant coral atoll?

I don't think this is the issue. Assuming any conflict starts after the fall of Nazi Germany, the front would be roughly at the demarcation between western and eastern Europe, bifurcating Germany and Austria and then following the Danube. Possibly including Yugoslavia. This would put Soviet airfields well within striking distance of airfields throughout Germany and eastern France. The USAAF is highly unlikely to build any strategic airbases under the air umbrella of the enemy combatant.

The other thing I think is being overlooked is that the bombing campaign at the beginning of such a conflict is not going to start making deep penetration raids against manufacturing. Rather, the primary objectives would be:

1. Destroy the Enemy Air Force
2. Degrade the Enemy's Ability to Operate in the Field.
3. Negate the Enemy's Numerical Superiority on the Ground

Given the starting point for such a conflict, there is no need for new air bases as the existing bases in England would provide coverage to the field of battle. This has been demonstrated over the previous three years of conflict. The Soviet ground forces numerical superiority at the start of such a conflict leads one to believe that the USSR would have the initiative from the onset of combat and it will be critical for western air forces to affect mobility as much as possible. The USSR would be vulnerable to an air campaign similar to that before the D-Day landings. Soviet forces were heavily reliant on railroads for resupply and large scale mobility. Targeting the rail infrastructure would have an almost immediate effect on Soviet operations. Soviet forces would also be vulnerable to the loss of trucks following the cessation of lend-lease. The USSR's best truck assets were all produced in the west and the inability to replace these would have a catastrophic impact on deep penetration offensives. We are also looking at very long supply lines for the USSR and a focused and extended campaign against resupply would severely hamper front line activities.

Last, the end of lend-lease would have as much an effect on Soviet industry as would a major bombing campaign against factories. Not only the loss of vehicles and spare parts for existing LL assets, but loss of critical raw materials, food stocks, and even uniforms would begin to limit Soviet ability to wage an effective campaign.

 

[muskeg13]

Or the USAAF OK's the use of JATO after the Navy shown it to work earlier in 1944
View attachment 800798
so this can happen
View attachment 800797

sooner than this 1949 flight

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.

 

[Thumpalumpacus]

The short answer is, no. A runway or roadway's bearing capacity is largely defined by the compaction of the soil beneath it. Simply adding top material won't enhance capacity without elaborate structural design. In the end it would be faster and cheaper to tear the runway up, add compaction, and put down a new surface.

... or just build new runways. Bring some Seabees over from the Pac and add them to Army engineers. What about this is prohibitive? Use medium bombers to suppress Soviet airfields housing fighters with their short ranges, take a month or two to build airfields for -29s, and while that's going on you stock up your 500- and 1000-lb bombs.

This is 1945. We're not n00bs at building airbase infrastructure. We don't have U-boats interfering with anything any more. We've got more B-29s than we can fit into the Marianas. And we've got, oh, I don't know, a few thousand B-17s, B-24s, and Lancasters that can reach 500 miles or so behind Soviet lines from extant German airfields while we're doing this buildup.

On the other hand, this is pretty much the USSR's first strategic-bombing rodeo. Even without B-29s being available the first few months, those Yaks are going to be ass-deep in alligators trying to drain the swamp.

 

[GrauGeist]

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 as well as the Tallboy (both U.S. and British versions), Grand Slam (both U.S. and British versions), Disney and others.