# A B-52 bomber in time for D-Day?



## Keslerian (Apr 16, 2018)

Some of you may have read the Axis of Time trilogy by John Birmingham. The series was about a fleet of warships from the year 2021. Due to a freak accident, they get sent back through time to June 2, 1942. Just before the battle of Midway. Their arrival changes the entire course of World War II. Among other things, Germany and the USSR make peace, and Japan decides to invade Australia. Profound cultural and scientific changes result from the 'emergence.'

Meanwhile, the military personnel from the 21st century agree to co-operate with the Allys, in order to bring the war to an end sooner. Among other things, the 'downtime' Americans immediately begin working on the B-52 bomber program. They make such rapid progress that a handful of prototypes are ready within 24 months. This didn't arouse my suspicions the first time I read the trilogy, years ago...

But now, this plot point strikes me as highly unfeasible! Since I'm not an expert on aircraft design, I'd like to get opinions from the posters here. My question to you is this: *Would it be possible (from an engineering standpoint) for the Americans to begin work on the B-52 program in June of 1942? And to get combat ready prototypes in time for D-Day?*

In my opinion, full blue-prints for the aircraft and its engines would undoubtedly be a big help for these guys. But the crude manufacturing technologys of the early 40's might not be up to the task... After all, the heavy press program was crucial in enabling the designers to utilise the most efficient wing shape possible. Without those huge forging machines, it would be alot harder.


----------



## swampyankee (Apr 16, 2018)

Completely impossible to build a B-52 in 1944 _even with the blueprints. _The technology to make the engines did not exist, and it would take years to develop.

Reactions: Agree Agree:
1 | Like List reactions


----------



## Keslerian (Apr 16, 2018)

swampyankee said:


> Completely impossible to build a B-52 in 1944 _even with the blueprints. _The technology to make the engines did not exist, and it would take years to develop.



We're talking about the J57 engines used on the early B-52 variants, right? Would you be able to elaborate what technologys were required to make them?


----------



## MIflyer (Apr 16, 2018)

In that series they also explained - without going into detail - that they used the technology from 2021 to build highly automated factories, which were compared to The Terminator movies in sophistication. The B-52 was designed circa 1950-51. I recall unfolding a B-52 component drawing, looking at the data on it, and telling the other engineers there that I could not work on it because it predated my birth (they were unimpressed with my reasoning but advised me not to drool on the drawings).

In terms of materials and other technology of 1942 the B-52 and its J-57 engines could be built. You need aluminum, steel, stainless steel and nickle alloys and all were available in abundance. No TI or composites required. Presumably they could have gone direct to the B-52 and J-57 and avoided the B-50, B-36, B-47, and numerous development steps and missteps along the way.

Do it in essentially 2 years? I donno. But five years is dead easy and three years very likely.

By the way, they also built a lot of F-86's, UH-1's, and AC-47's.


----------



## Keslerian (Apr 16, 2018)

MIflyer said:


> In that series they also explained - without going into detail - that they used the technology from 2021 to build highly automated factories, which were compared to The Terminator movies in sophistication. The B-52 was designed circa 1950-51. I recall unfolding a B-52 component drawing, looking at the data on it, and telling the other engineers there that I could not work on it because it predated my birth (they were unimpressed with my reasoning but advised me not to drool on the drawings).



Yeah, I remember that part. It comes off as an unconvincing hand wave, though. Why would the Navy have a bunch of manufacturing tech on board their ships? The fleet from 2021 was a _pure combat force_, there weren't any cargo ships that would be hauling stuff like that around. I could understand if they had some 3D printers on board or what not. But theres no way they would have a bunch of advanced machine toolst.

So really, the Boeing engineers would have to rely exclusively on the technology that already existed in 1942. Or at least, whatever manufacturing tech they could bootstrap their way to within the given time frame. Would it be possible for them to construct those big forging presses? From my understanding, they were necessary for the wing assemblys.



MIflyer said:


> In terms of materials and other technology of 1942 the B-52 and its J-57 engines could be built. You need aluminum, steel, stainless steel and nickle alloys and all were available in abundance. No TI or composites required. Presumably they could have gone direct to the B-52 and J-57 and avoided the B-50, B-36, B-47, and numerous development steps and missteps along the way.
> 
> Do it in essentially 2 years? I donno. But five years is dead easy and three years very likely.
> 
> By the way, they also built a lot of F-86's, UH-1's, and AC-47's.



If you had to go out on a limb, what part of the engine would be the hardest to recreate using 1940s tech? Don't the turbine blades for a jet engine require fairly high tolerances?

Like you said, doing it all in just 24 months seems like quite a stretch!

Honestly, I think they would have an easier time building the engine for an AC-47 than for a B-52. A radial engine is easier to build than an axial flow jet engine. The Americans didn't build any of those during WW2 (except for the J31 engines, arguably). Somewhat ironically, the Germans had the lead in that department.


----------



## pbehn (Apr 16, 2018)

If you are just handing a blue print to someone else with no knowledge to build you also need to hand over all the material specs and from them all the testing specs for everything used, then get some very clever people and set them going reading for a month or perhaps a year

When the Russians reverse engineered the B-29 they didn't have the gauge of aluminium so they made it a little heavier and they didn't reverse engineer the engines.


----------



## MIflyer (Apr 16, 2018)

The US Navy has computer controlled manufacturing capabilities on its ships right now, and have had for decades. They have Haas computer controlled machines on board, which makes a sailor who is able to read a manual a pretty good machinist.

But they could have taken the technology they had available and built computer controlled manufacturing equipment. They had automated manufacturing equipment in WWII as it was. Biggest problem with anything they did would be how much to improve it versus leaving it alone. For example, I think I'd build the B-49 rather than the B-52. The computer controlled stability augmentation systems likely would have solved the problems with the flying wing. Going straight to the B-2 would be hard to do, but the B-49 should be pretty easy.

I've often wondered what I could do to help if I went back to 1942. What could I do other than telling them what to focus on that they were soon going to do anyway? Now, a whole force of advanced ships showing up is a different situation.


----------



## J.A.W. (Apr 16, 2018)

There was a movie made along these lines a couple of decades or so ago, where a CVN weirdly intruded into 
the waters of Hawaii in early Dec `41, & the skipper had to agonise about not using F-14s to waste Nagumo's fleet..


----------



## Keslerian (Apr 16, 2018)

MIflyer said:


> The US Navy has computer controlled manufacturing capabilities on its ships right now, and have had for decades. They have Haas computer controlled machines on board, which makes a sailor who is able to read a manual a pretty good machinist.



Hmm, I didn't know that. You learn something new every day! But with that said, these aren't exactly huge machines. Theres a limit on the kindof work they can do. Presumably, the Haas machines wouldn't be able to work on really large components.



MIflyer said:


> But they could have taken the technology they had available and built computer controlled manufacturing equipment. They had automated manufacturing equipment in WWII as it was. Biggest problem with anything they did would be how much to improve it versus leaving it alone. For example, I think I'd build the B-49 rather than the B-52. The computer controlled stability augmentation systems likely would have solved the problems with the flying wing. Going straight to the B-2 would be hard to do, but the B-49 should be pretty easy.



Could they have? I'm not so sure. CNC machines from the 70s-80s onward used microchips to control their functions. That means integrated circuits, and millions of transistors. You can't build microchips in the 1940s, its flat out impossible. You need to master the planar process first, so you can effectively mass produce transistors. Then you need a new kind of microscope in order to view the chip architecture. Etcetera. Anything to do with modern computers requires multiple technological breakthroughs that cannot be achieved in the time frame of WW2.

Outside of that domain, though, the downtime Americans would have more options available to them. They could make incremental improvements to their own machine tools, maybe on to models running off punched tape. I have no idea what they'd need to make the J57 engines, though. Would you be willing to hazard a guess?



MIflyer said:


> I've often wondered what I could do to help if I went back to 1942. What could I do other than telling them what to focus on that they were soon going to do anyway? Now, a whole force of advanced ships showing up is a different situation.



Yeah, its a tough call. The fight against the Japanese went about as well as can be expected. And as for the Germans, their fate depended mostly on how they dealt with the Soviet Union. The Americans and British didn't have much influence on the eastern front (beyond lend lease).

Reactions: Agree Agree:
1 | Like List reactions


----------



## nuuumannn (Apr 17, 2018)

Kaslerian, I agree about computer technology, not going to happen in WW2.



Keslerian said:


> I have no idea what they'd need to make the J57 engines, though. Would you be willing to hazard a guess?



Similar with 1950s and 60s jet engines. The materials used and temps and pressures achieved didn't happen overnight. It came from an evolutionary process that began before WW2, therefore things needed to happen first. Running before you can crawl never works. There are examples in history of technological advance way ahead of its time failing. AA Griffith's compressor designs for RR are an example. RR built one and found they couldn't get it to work because the materials were not up to the task of doing what was required. You can't build the Space Shuttle without having built the A4 rocket first.

Reactions: Agree Agree:
1 | Like List reactions


----------



## wuzak (Apr 17, 2018)

J.A.W. said:


> There was a movie made along these lines a couple of decades or so ago, where a CVN weirdly intruded into
> the waters of Hawaii in early Dec `41, & the skipper had to agonise about not using F-14s to waste Nagumo's fleet..



_The Final Countdown_.

The captain did authorize an attack against the Japanese fleet, but the storm returned and whisked them back to their original time, leaving one crew member behind.

Reactions: Agree Agree:
1 | Like List reactions


----------



## wuzak (Apr 17, 2018)

nuuumannn said:


> Similar with 1950s and 60s jet engines. The materials used and temps and pressures achieved didn't happen overnight. It came from an evolutionary process that began before WW2, therefore things needed to happen first. Running before you can crawl never works. There are examples in history of technological advance way ahead of its time failing. AA Griffith's compressor designs for RR are an example. RR built one and found they couldn't get it to work because the materials were not up to the task of doing what was required. You can't build the Space Shuttle without having built the A4 rocket first.



The processes involved in manufacturing the turbine and compressor blades was not really available in the US in 1942, or anywhere. These processes were in the very early stages of development in 1942.


----------



## J.A.W. (Apr 17, 2018)

Cheers Wayne, yeah - that's the one..

& @ N-man, are you suggesting that an SS Colonel ( Dr von Braun) could be induced to defect..
..prior to using his A4/V2 - in an 'honest attempt' - to lay waste to London, as a final 'proof of concept'?


----------



## J.A.W. (Apr 17, 2018)

wuzak said:


> The processes involved in manufacturing the turbine and compressor blades was not really available in the US in 1942, or anywhere. These processes were in the very early stages of development in 1942.



SS Colonel Dr von Braun might have been able to help with that one too, his fuel-delivery turbo-pump tech,
& high-temp, supersonic-proven metallurgical knowledge - was 'state of the art' - at that time..


----------



## wuzak (Apr 17, 2018)

I wonder if something like an A6 would be more useful and less difficult for the times?

Obviously the range is the problem compared with the B-52. And the engine issue is the same (when the XP-59 first flew its engines gave 2 x 1,300lbf thrust, the A6 needs 2 x 9,000lbf and the B-52 8 x 10,000lbf).

But if you still have bases in the UK, the A6 would give the Germans a lot of strife.

And, if you are being ambitious, you could also build versions of the A6 for buddy refueling systems, extending the reach into Russia.

Once you have secured, at least part of, Europe, you could head down through India, Malaysia and Indonesia to take back Australia (if Japan's invasion had been successful).


----------



## wuzak (Apr 17, 2018)

In terms of size, the A6 is not much bigger than the TBF Avenger. Smaller wingspan, slightly longer and higher. Though it is 3.5 times as heavy when fully loaded. So it could prossibly work on the larger US carriers, though the equipment would not be up to launching or arresting it.


----------



## J.A.W. (Apr 17, 2018)

WW2 US carriers had wooden decks.. likely too flimsy - but Brit flat-tops featured armoured strips..


----------



## MIflyer (Apr 17, 2018)

The V-2 engines did not use much in the way of high temp materials. The Germans did not have access to those ores. Rather than using a gas generator to drive the turbopump turbine they used H202, which is a much colder reaction and meant the V-2 engine did not need as much in the way of nickle. That same problem killed their jet fighter program.

And there is nothing needed to build the B-52 in 1952 that was not available in 1942. If you suppose that the later knowledge as to alloys and designs are supplied, you are there. The big question is: would you even build a B-52 or something better?

The transistor was accidentally discovered in 1921 and invented in 1946. A four year advancement - and then some - in that technology would be trivial to implement. And computers do not have to be the size of a paperback book to work.


----------



## T Bolt (Apr 17, 2018)

Instead of a B-52 program why not kick start the B-36 program. You wouldn't have to worry about a jet engine and a fleet of B-36's in 1944 would have been pretty devastating. If it was found that a jet engine could be produced later than use the B-36 fuselage and produce a B-60


----------



## vikingBerserker (Apr 17, 2018)

Or build ballistic missiles instead.


----------



## MIflyer (Apr 17, 2018)

Take it from someone who has launched rockets. The step between a B-29 and the B-52 is much smaller than the step between Goddard and Atlas D. But in those books the purpose of the B-52 was to haul nukes; they only needed a few of them to do that.

I think it would be easier to go straight to the B-49 rather than the B-36.


----------



## vikingBerserker (Apr 17, 2018)

Well the technology already existed for the needed rocket (V-2) and it's not like a nuke has to have pin point accuracy.

Most importantly, it could not be shot down by flak or fighters.

Reactions: Like Like:
1 | Like List reactions


----------



## Glider (Apr 17, 2018)

If we are into fantasy the Canberra would be more feasible and have almost as big an impact

Reactions: Agree Agree:
2 | Like List reactions


----------



## tomo pauk (Apr 17, 2018)

Glider said:


> If we are into fantasy the Canberra would be more feasible and have almost as big an impact



Seem to me that you've forget that pieces of kit need to be designed in a cool country in order to feature in a book, let alone in a movie...

Reactions: Like Like:
1 | Like List reactions


----------



## Glider (Apr 17, 2018)

Your right, perfect square jaws, perfect teeth, sun kissed beaches and palm trees I get it. Been to Southend recently?
southend seafront - Bing images


----------



## Keslerian (Apr 18, 2018)

wuzak said:


> The processes involved in manufacturing the turbine and compressor blades was not really available in the US in 1942, or anywhere. These processes were in the very early stages of development in 1942.



My knowledge on this subject is limited. Would you be able to explain further?



wuzak said:


> I wonder if something like an A6 would be more useful and less difficult for the times?
> 
> Obviously the range is the problem compared with the B-52. And the engine issue is the same (when the XP-59 first flew its engines gave 2 x 1,300lbf thrust, the A6 needs 2 x 9,000lbf and the B-52 8 x 10,000lbf).
> 
> But if you still have bases in the UK, the A6 would give the Germans a lot of strife.



Yeah, the A6 would be really useful. Its like the ultimate attack aircraft in a WW2 setting. Incredibly fast, agile, good rate of climb, and a very impressive payload too: It can carry more ordnance than a friggin' B-17!


----------



## Keslerian (Apr 18, 2018)

MIflyer said:


> The V-2 engines did not use much in the way of high temp materials. The Germans did not have access to those ores. Rather than using a gas generator to drive the turbopump turbine they used H202, which is a much colder reaction and meant the V-2 engine did not need as much in the way of nickle. That same problem killed their jet fighter program.
> 
> And there is nothing needed to build the B-52 in 1952 that was not available in 1942. If you suppose that the later knowledge as to alloys and designs are supplied, you are there. The big question is: would you even build a B-52 or something better?



Well, the absence of the heavy press program would be a PITA. But not necessarily a crippling problem.



MIflyer said:


> The transistor was accidentally discovered in 1921 and invented in 1946. A four year advancement - and then some - in that technology would be trivial to implement. And computers do not have to be the size of a paperback book to work.



I can't really agree with that. After all, there is a pretty massive leap between the invention of the transistor, the invention of the integrated circuit, and then the microprocessor. There was a computer in 1953 that used 200 point-contact transistors and 1300 point diodes. (That was about the best they could do at the time, because transistors are impossible to mass produce without the planar process)

Once the integrated circuit was built, transistors got progressively smaller with each generation, which allowed designers to put more and more of them onto a silicon chip. ''The INTEL 4004 Microprocessor that was introduced in 1971 had 2,300 transistors. The INTEL Pentium 4 Processor introduced in 2000 had 42,000,000 transistors.'' The downtimers can do lots of things with their future knowledge, but building computers isn't really one of them.


----------



## wuzak (Apr 18, 2018)

Keslerian said:


> My knowledge on this subject is limited. Would you be able to explain further?



I think in the way the blades were constructed - evolved from sheet metal to precision cast or forged - and the way they are connected to the hub.


----------



## J.A.W. (Apr 18, 2018)

Also, apart from pains-taking thermo-development in the hot-turbine section,
a steady transitition in compressors - between high-speed & sub-sonic usage, with more bypass fan use for the latter,
all to get some 1/2 decent fuel economy - from this thirsty ICE machine..


----------



## J.A.W. (Apr 18, 2018)

I'll add that SS Colonel Dr von Braun & his mob of Nazi rocket scientists
- do deserve aero-space credit for proving that such a large technically-complex
machine could power through the putative 'sound-barrier' intact..

& to handle such heat & shock stresses, arcing high across the Earth's curve
as an effective ballistic-missile, it was pretty impressive for 3/4s of century ago..
regardless of its actually negligible war-weapon value..


----------



## J.A.W. (Apr 18, 2018)

& on the matter of computer develpment, I recall reading many years ago that
in 1945, ADGB were working on plans to use their new-fangled computer to integrate
a control system, so as to operate a radar directed, proximity fuse-tipped, heavy flak barrage
intended to down von Braun & Dornberger's V2's, right then - arcing down on London..

In fact, while von Braun was rapidly 'Paperclipped' by US security forces, ol' Dornberger
was held by the Brits for a couple of years, to help with such matters - under threat of
war-crimes prosecution - for non-compliance..


----------



## GrauGeist (Apr 18, 2018)

The B-36 was already in development during WWII, it's first flight was just shortly after the conclusion.
Given it's size, speed and payload capabilities for the time, it was the most advanced bomber without rival and would remain at the top for nearly a decade.

For contrast, the Soviet Union had the Tu-4 (reverse-enginered B-29) as their primary bomber...


----------



## J.A.W. (Apr 18, 2018)

Nah, the B-36 was the epitome of a humungous 'white elephant' - that only the US could afford..
( even then, it was a 'close run thing' - against the USN's new 'big carrier' demands,
& only saved by 'the bomb' )
..it was obsolescent by the time it got into service ( & oh yeah - it was a horror, to service)..

Chuck Yeager enjoyed putting the hopes of the USAF 'bomber mob' straight,
on the gun-aiming problems of the MiG 15 he evaluated.. along the lines of..

'Sure its lousy, but its big cannon can 'cover the spread' - offered the by the bloated B-36's planform!'


----------



## GrauGeist (Apr 18, 2018)

J.A.W. said:


> Nah, the B-36 was the epitome of a humungous 'white elephant' - that only the US could afford..
> ( even then, it was a 'close run thing' - against the USN's new 'big carrier' demands,
> & only saved by 'the bomb' )
> ..it was obsolescent by the time it got into service ( & oh yeah - it was a horror, to service)..
> ...



WTF are you even going on about?

The B-36 was the world's first nuclear delivery platform, it had a cruising speed faster than most contemporary fighters of the day, it had a max. conventional loadout that would only be surpassed by the B-52.

There is no way it was "obsolescent" by the time it got into service (1949) because there wasn't anything else that could match it for years - It was put to paper in 1941 and saw it's first flight in 1946 - it was in service less than three years later. Nothing that ANY nation produced could match it.

So either you're sadly misinformed or you're just making noise to discount my post. In either case, go read a book, learn WTF you're talking about and come back when you have something to bring to the table.

Reactions: Agree Agree:
2 | Like List reactions


----------



## J.A.W. (Apr 18, 2018)

Hey man.. of the two us, guess who could really use some more 'book learning',
likely its the Ford-Merlin & Wright-fighter faux pas guy.. right?

The B-36 was 'meat-on-the-plate' for the MiG 15, which is why not even one - was used in Korea..
& unlike the B-52, ( which has served the USAF well, for many decades & is still going strong)
the ungainly 'maintainers nightmare' B-36 never so much as dropped a bloody hand grenade, in anger..

Curtis LeMay, SAC boss hated 'em & could hardly wait to be rid of those sodding sauropods..


----------



## vikingBerserker (Apr 18, 2018)

So in the book there were Mig 15s?????? Did I miss something that the Russians were fighting the US?


----------



## J.A.W. (Apr 18, 2018)

Maybe they jumped out of the 'Zero was too good...' thread, having learned the 3 essentials from those wily Nippons..
Surprise, fear & ruthless effciency..


----------



## MIflyer (Apr 18, 2018)

Yes, in the book the Soviets were working on building Mig-15's. The info from 2021 not only provided technical data but knowledge of what was going to happen after the war as well. In the book, before WWII was over it evolved into a secret war between the US and the USSR, not necessarily with the approval of the senior leadership of 1945. The people from the future knew that it was vital to strangle the Red baby in its crib. 

So a B-49 or B-52 would be better than a B-36.

As for computers, it was explained that everyone aboard those time traveling ships had multiple personal laptops, tablets, iphones, etc. Each one of those items had more computing capability than existed anywhere else in 1942. Joseph Gobbels was even brought to tears by the frequent message "Windows Has a Problem And Needs to Shutdown Right Now."


----------



## vikingBerserker (Apr 18, 2018)

Ok, this makes more sense to me - thank you.

I stick with the ballistic missiles then as being the best alternative. German V-2 like rocket with a nuke and a better guidance system.


----------



## Shortround6 (Apr 18, 2018)

The Problem a lot of these time travel books have is that the "time travelers" do NOT bring all the technical information of how to produce the weapons/planes/ships they have with them. 

And unfortunately for even time travel reality ( there is a real stretch in itself) the planes/engine/ computers of 2021 (or even 2001) are generations different than the even the prototype engines of 1941 so that the only things they have in common is general operating principles.
In aircraft fabrication they were using those big Hydraulic presses to bend chemically milled sheets.





WIthout the knowledge of how to do chemical milling the big hydraulic presses are much less useful. 

In the turbine engine there a number of generations in such things as turbine blades, some of which had nothing in common with their predecessors except shape. For instance RR went, in the years between 1972 and 1987, from an inlet temperature to the turbine of 1530degrees K to 1739 degrees K. using not only different alloys and different layouts of air passages to cool the blades but 3 different casting techniques. This is on the Civil RB 211 turbo fan. 
up until 1977 the blades were investment cast in a traditional multi axis grain structure. Between 1977 and 79 they developed a way to cast the blades with very long lengthwise crystals nearly eliminating any crosswise grain boundary lines and greatly increasing tensile strength. Later they were able to make blades that were actually one large crystal. 
Even if you had some of these to examine in a 1942 laboratory, how do you duplicate them? 
Or how do you try to backdate any of their features (except for overall shape) to the materials and fabrication techniques used in WW II.

I would note that it usually took around two years (at best) during WW II from breaking ground on a new factory to actually getting mass production numbers of either engines or airframes. This was for engines/ airframes using pretty much existing technology. You can't build the factory until you know what machinery is needed to put in it and for mass production the machines have to placed in a logical order (and near whatever services are going to be needed, electrical, compressed air, steam, nitrogen supplies, etc. When I worked at P & W 40 years ago some of the machines extend down below floor level and had large cooling tanks for the cooling fluid poured on the piece and the cutter/s as the piece was worked on. Trying to move machines after they are installed is a major pain in the ass.

Reactions: Like Like:
1 | Agree Agree:
1 | Like List reactions


----------



## MIflyer (Apr 18, 2018)

Well, we are not talking about building a F-22 in 1942 but a B-52, and not one with EVS, FLIR, and SRAM, either. And in the book they said they would build P-51's followed by F-86's and A-4's followed by F-5's. And the time travelers would not have to do it all by themselves.

But here is an interesting article that deals with the idea a bit more realistically, although using a more extreme example.

Look on page 61, the article, "No Copying Allowed": Collected editorials from Analog : Campbell, John Wood, 1910-1971 : Free Download, Borrow, and Streaming : Internet Archive

Reactions: Winner Winner:
2 | Like List reactions


----------



## Shortround6 (Apr 18, 2018)

Ok, but how does taking a few turbine blades out of an F22 and comparing them to the turbine blades in a prototype Whittle jet tell you HOW TO MAKE the blades in a J-57? 

This is almost, but not quite, equivalent to sending a group of WW II ships and sailors back to the American Civil war and trying to build even Martin B-10s and Curtiss Hawk biplanes in 2 years. The industry/infrastructure simply doesn't exist.


----------



## MIflyer (Apr 18, 2018)

The GE J-35 axial flow jet engine was in production in 1945. The J-47 was in production in 1948.


----------



## pbehn (Apr 18, 2018)

You cannot underestimate how much knowledge a company has within all its staff. The company that built the B-52 had progressed from the B-29 and the B-17 with many other types too. That is an awful lot of mistakes made and learned from as planes became more complex. Personally I think if you made everyone redundant who worked on the B-52 and replaced them with equally intelligent workers with no experience but all the manuals and procedures you wouldn't get a B-52 in two years and a lot of people would be killed and injured in the process. I worked in a factory that had just been mothballed for 4 years and the management kept on, it took months to get going as everyone learned what the previous workers knew.


----------



## J.A.W. (Apr 18, 2018)

pbehn said:


> You cannot underestimate how much knowledge a company has within all its staff. The company that built the B-52 had progressed from the B-29 and the B-17 with many other types too. That is an awful lot of mistakes made and learned from as planes became more complex. Personally I think if you made everyone redundant who worked on the B-52 and replaced them with equally intelligent workers with no experience but all the manuals and procedures you wouldn't get a B-52 in two years and a lot of people would be killed and injured in the process. I worked in a factory that had just been mothballed for 4 years and the management kept on, it took months to get going as everyone learned what the previous workers knew.



True, post-war examination of Nazi-tech brought some surprises...
& one for Sid Camm, chief designer at Hawker, was that Focke-Wulf had
300 research staff dedicated to investigating 'blue-sky' (non-direct) stuff,
- while he'd had to make do with a mere handful of design staff, all of 'em horribly over-stretched..


----------



## MIflyer (Apr 19, 2018)

Shortround6 said:


> Ok, but how does taking a few turbine blades out of an F22 and comparing them to the turbine blades in a prototype Whittle jet tell you HOW TO MAKE the blades in a J-57?



It's called "Math." But it is true that you probably would not build a J-57 or even a B-52 but something better.

Just knowing what you were going to do that did not work and what you did that did work is of immense value.


----------



## Shortround6 (Apr 21, 2018)

MIflyer said:


> It's called "Math." But it is true that you probably would not build a J-57 or even a B-52 but something better.



Math may tell how and why the blade was shaped the way it was. It does nothing to tell "how" the blade was made. Casting/forging techniques, modern machining techniques, metallurgy and the like. Some of which are as far removed from 1942 metal working as a modern cell phone is from a 1942 rotary dial phone.

Reactions: Like Like:
1 | Like List reactions


----------



## Keslerian (Apr 21, 2018)

Shortround6 said:


> The Problem a lot of these time travel books have is that the "time travelers" do NOT bring all the technical information of how to produce the weapons/planes/ships they have with them.
> 
> And unfortunately for even time travel reality ( there is a real stretch in itself) the planes/engine/ computers of 2021 (or even 2001) are generations different than the even the prototype engines of 1941 so that the only things they have in common is general operating principles.
> In aircraft fabrication they were using those big Hydraulic presses to bend chemically milled sheets.
> Without the knowledge of how to do chemical milling the big hydraulic presses are much less useful.



I agree. It going to be a very specific piece of information, and the odds are against it being in a ships data archives. It'll be a document with some obscure and technical name, like: ''Metallurgical fabrication of the B-52 airframe.'' Or maybe: ''Engineering analysis of the P&W J57 turbine blades.''

*Maybe* the downtimers will get lucky, and someone in the 2021 fleet will have a PDF of this document. But if they don't, then things get alot more complicated... Reverse engineering without the requisite knowledge is really hard.



Shortround6 said:


> In the turbine engine there a number of generations in such things as turbine blades, some of which had nothing in common with their predecessors except shape. For instance RR went, in the years between 1972 and 1987, from an inlet temperature to the turbine of 1530degrees K to 1739 degrees K. using not only different alloys and different layouts of air passages to cool the blades but 3 different casting techniques. This is on the Civil RB 211 turbo fan.
> up until 1977 the blades were investment cast in a traditional multi axis grain structure. Between 1977 and 79 they developed a way to cast the blades with very long lengthwise crystals nearly eliminating any crosswise grain boundary lines and greatly increasing tensile strength. Later they were able to make blades that were actually one large crystal.



Good point. The first mention I can find of this 'single crystal' casting method was a business week document from 1966. This is what it said specifically:

''For basic research, P&W set up a metallurgy group six years ago that now has 35 Ph.d's among its staff of 100. Earlier this year, the group came up with a method of casting nickel alloys to produce a "single-crystal" structure that is four times more durable than conventionally cast material. P&W will use the process to cast turbine blades and vanes.''

I'm guessing that the blades on the J57 engine probably didn't use these kindof production techniques... But even so, they could still be problematic for 1940s engineers to reconstruct. Without knowing the specifics, its hard to say one way or another.



Shortround6 said:


> Even if you had some of these to examine in a 1942 laboratory, how do you duplicate them?
> Or how do you try to backdate any of their features (except for overall shape) to the materials and fabrication techniques used in WW II.
> 
> I would note that it usually took around two years (at best) during WW II from breaking ground on a new factory to actually getting mass production numbers of either engines or airframes. This was for engines/ airframes using pretty much existing technology. You can't build the factory until you know what machinery is needed to put in it and for mass production the machines have to placed in a logical order (and near whatever services are going to be needed, electrical, compressed air, steam, nitrogen supplies, etc. When I worked at P & W 40 years ago some of the machines extend down below floor level and had large cooling tanks for the cooling fluid poured on the piece and the cutter/s as the piece was worked on. Trying to move machines after they are installed is a major pain in the ass.



Yeah, going from a blank sheet to an actual, flyable B-52 bomber in 24 months is a real stretch. Granted, there were only a handful of them in Birminghams story, but that still seems implausible. Honestly, it would have been more realistic if the Americans had gone for the B-36 design. Or even a buffed out B-29. Creating an highly advanced aircraft from scratch when you don't even have all the infrastructure in place is going to run into delays. Blueprints are nice, but they don't fix other things.


----------



## Shortround6 (Apr 21, 2018)

Thank you for finding that
I may have stated it badly, but what I meant or was trying to get across was that the fabrication of the modern (post 2000?) compressor and turbine blades are probably more removed from the J57 engine than the blades of an early Whittle jet are. 
A bit like trying make a 1950s tube color TV set when your only examples are this:





and a 60 in HD plasma screen.


----------



## MIflyer (Apr 22, 2018)

Well, once again we are not talking about building a 2018 or even a 1970 airplane in 1942. Detailed design of the B-52 was under way in 1951; I have worked with some of the drawings. The design of the J-47 was begun before the end of WWII. No new materials were required for the J-47 or the J-57. They already had considerable experience with high temp nickel alloys because of the many thousands of turbosuperchargers manufactured before and during WWII. What impeded jet engine development in the early 40's was not the materials and fluid dynamics but "minor" things, like how you make a fuel spray nozzle that will ensure the fuel lights, stays lit, and burns efficiently, as well as basics like "Should you make the air from the compressor do a 180 degree turn on its way to the turbine?" Tell the people of 1942 how not to screw up and they'll get it done even faster.

If in 1975 I had known that Airresearch was shipping boost venturis they had not bothered to calibrate I could have gotten the F-111D/F fixed a lot faster. Of course, if they had stopped with silly $hit like, "Your highest priority is now is writing a report on the loss of a $27.50 flight jacket that was in the possession of an airman in another unit." that would have helped a lot too.


----------

