Avro Manchester, Lancaster, Lancastrian, Lincoln, Shackleton

[rickshaw]

What isn't appreciated is the difficulties of switching en masse from metal to wooden construction.  The advantage of the Mosquito was that it used up unused production capacity - timber workers, primarily from the furniture trade who weren't be usefully employed in other war work.   While there were more than likely such workers in the US, just as in the UK, it would have been a finite quantity which would have been the main limit on just how many and how fast Mosquitoes could be constructed.   Of course, metal trained aero workers could have been retrained but that would have taken time, further prolonging the war.

The US aero industry was pretty firmly wedded to metal construction by 1941.  It lent itself to US production techniques and design methods.  Switching to timber would have been difficult.  Yes, the US military was concerned about "strategic materials" shortages but they didn't eventuate in the way they had feared and so experiments like the XP-77 didn't really work out as US aero companies found it difficult to make the switch.  A similar situation developed in Germany with the Ta-154 and the Ju-322.  What seems to be ignored in these sorts of discussions is the difficulty of switching an entire industry rapidly from one form of construction to another.   Which is why I suggested that perhaps it might have been better to design a metal Mosquito.  Hopefully it would have the near or same performance but be easier and faster to manufacture.   Again, I cannot think of such an aircraft, perhaps someone else can?

[kitnut617]

  Which is why I suggested that perhaps it might have been better to design a metal Mosquito.  Hopefully it would have the near or same performance but be easier and faster to manufacture.   Again, I cannot think of such an aircraft, perhaps someone else can?

Well not a metal Mosquito, but a metal Hornet comes close so there is some credence to your argument:

[kitnut617]

But I do believe this was made of metal which is very close to a Mosquito.

EDIT: oops sorry, no it wasn't.  But the Nancu definitely was made all of metal.

[Weaver]

The thing is though, this is taking place in the context of a massive production build-up, so you're not "switching" an industry from metal to wood, but "adding" an entire new production organisation in parrallel to the established ones. Also, the restriction on the number of qualified woodworkers applied just as much to the skilled machinists and metal workers needed for conventional aircraft production and could be overcome in similar, or less time by the same method: a massive training programme. It's also a bit easier to to train people to glue and nail wooden structures together than it is to train them to rivet, weld and machine metal.

[kitnut617]

According to the Sharp/Bowyer book, most of the Mosquito production in the UK was made by cabinet & furniture builders and the like all over the country so no training would be required as the US had a similar workforce.

[rickshaw]

According to the Sharp/Bowyer book, most of the Mosquito production in the UK was made by cabinet & furniture builders and the like all over the country so no training would be required as the US had a similar workforce.

Wood workers require considerably more training than metal workers.  I am not suggesting such workers were not available in the US but rather, just like in the UK, there was a finite upper limit on their availability.  While metal workers had to be trained without a doubt, it was easier and faster to train them.

[kitnut617]

According to the Sharp/Bowyer book, most of the Mosquito production in the UK was made by cabinet & furniture builders and the like all over the country so no training would be required as the US had a similar workforce.

Wood workers require considerably more training than metal workers.  I am not suggesting such workers were not available in the US but rather, just like in the UK, there was a finite upper limit on their availability.  While metal workers had to be trained without a doubt, it was easier and faster to train them.

The point I was trying to make Rick, was that the wood workers were already trained and were a vast but un-tapped resource, and available to make wood aircraft which is what Geoffrey de Havilland was trying to utilize and put towards the war effort.  All they had to learn was the quirks of making an aircraft, not how to do woodwork, and in the States they was an even bigger work force of cabinet/furniture craftsmen.  But I agree that the metal workers were easier to train, but they didn't have to do very much anyway as all they did was assemble the parts.  Once shown how to put a rivet in and how to put a bit of metal into a jig, then off they went.  Much the same as the auto industry is then (and today) as they didn't make the metal, they didn't bash the metal into shape as this was all done by a few pattern makers to make the pre-production bits and then machines took over to make and bash the parts out to which semi-skilled people were used to assemble them.

[jcf]

Once shown how to put a rivet in and how to put a bit of metal into a jig, then off they went.  Much the same as the auto industry is then (and today) as they didn't make the metal, they didn't bash the metal into shape as this was all done by a few pattern makers to make the pre-production bits and then machines took over to make and bash the parts out to which semi-skilled people were used to assemble them.

Well yes and no, building an aircraft structure is vastly different from a stamped auto-body.

http://www.youtube.com/watch?v=OrOQRLzgZqI

[kitnut617]

Well yes and no, building an aircraft structure is vastly different from a stamped auto-body.

Nice film clip Jon, but being in the steel industry and coming from the shop floor (steel fabrication) I don't see the difference.  People from all walks of life were hired and put to work building aircraft, there were a few craftsmen but 90% were right off the street.  The system used was the same as the auto industry, same people doing the same thing all day and putting a rivet in isn't rocket science.  Watching the clip I think I saw maybe three or four craftsmen, the rest were assemblers.

One of my jobs I did frequently was making jigs so others could assemble things, drilling jigs, assemble jigs, all sorts. The jigs I made had to be so the others didn't have to think about anything other than get the right part in the jig in the right sequence and then put in the right bolt, rivet or put a spot weld on.  Not a lot different to what I saw in the clip.

Robert

[jcf]

Well yes and no, building an aircraft structure is vastly different from a stamped auto-body.

Nice film clip Jon, but being in the steel industry and coming from the shop floor (steel fabrication) I don't see the difference.  People from all walks of life were hired and put to work building aircraft, there were a few craftsmen but 90% were right off the street.  The system used was the same as the auto industry, same people doing the same thing all day and putting a rivet in isn't rocket science.  Watching the clip I think I saw maybe three or four craftsmen, the rest were assemblers.

One of my jobs I did frequently was making jigs so others could assemble things, drilling jigs, assemble jigs, all sorts. The jigs I made had to be so the others didn't have to think about anything other than get the right part in the jig in the right sequence and then put in the right bolt, rivet or put a spot weld on.  Not a lot different to what I saw in the clip.

Robert

I'm referring to the notion (not from you but I've heard it elsewhere and fairly often, mostly from modelers  ) that aircraft were/are assembled from stampings like a car body.
I think it arises from a misunderstanding of what happened when the car companies went into aircraft production and some folk assume
that identical methods were used.

My brother can tell you horror stories from his time on the 777 (as an actual licensed A&P he could only deal with it for two years) line where you had guys who figured  "jigs? jigs? we don need no stinkin' jigs" or drill guides, with, as you'd expect, the predictable result of expensive parts being screwed up. Usually the violators were the longest term and, supposedly, most experienced aka skilled hands. Of course there is a difference between fifteen to twenty years experience in a given field and doing the same task for fifteen to twenty years.

Jon

[jcf]

[* The same could be said for DHC. Their only experience with moulded plywood fuselages prior to the Mosquito was assembling the Dragonfly. Wartime Downsview production line personnel were largely trained on the job. Few had prior aircraft or furniture production experience.]

You are forgetting the DH 91 Albatross and DH 93 Don, both were of stressed-skin 'moulded-ply' wood construction.

Jon

[jcf]

Jon,

Just to clarify, I was referring to DeHavilland Canada's experience prior to building Mosquitos at Downsview. DHC's actual production was limited to DH.82s and DH.83s (aircraft like the Rapide and Dragonfly were assembly jobs only).

Otay, missed the C. Mea culpa.
I'm a bad Canadian.

[jcf]

What isn't appreciated is the difficulties of switching en masse from metal to wooden construction.  The advantage of the Mosquito was that it used up unused production capacity - timber workers, primarily from the furniture trade who weren't be usefully employed in other war work.   While there were more than likely such workers in the US, just as in the UK, it would have been a finite quantity which would have been the main limit on just how many and how fast Mosquitoes could be constructed.   Of course, metal trained aero workers could have been retrained but that would have taken time, further prolonging the war.

The US aero industry was pretty firmly wedded to metal construction by 1941.  It lent itself to US production techniques and design methods.  Switching to timber would have been difficult.  Yes, the US military was concerned about "strategic materials" shortages but they didn't eventuate in the way they had feared and so experiments like the XP-77 didn't really work out as US aero companies found it difficult to make the switch.  A similar situation developed in Germany with the Ta-154 and the Ju-322.  What seems to be ignored in these sorts of discussions is the difficulty of switching an entire industry rapidly from one form of construction to another.   Which is why I suggested that perhaps it might have been better to design a metal Mosquito.  Hopefully it would have the near or same performance but be easier and faster to manufacture.   Again, I cannot think of such an aircraft, perhaps someone else can?

Something to bear in mind is that the basic techniques used to build the Mossie were not new, unique nor rocket science
the basic methods had been in use since the later half of the 19th century in the mass production of wooden canoes.
Racing shell construction was also well established in the US and UK.

If the US had need to switch to wood construction they would have and it would not have been as painful as you seem to believe.
Wood monococque airframe construction methods were not foreign to US designers or firms, the LWF and Lockheed methods
(among others) were known and the Fairchild Duramold system was available.

The XP-77 failed because it was a nowhere concept, its construction material was not the issue and it had nothing to do
with US industry having difficulty switching materials.

The Germans also had extensive experience with wood construction techniques, the Ta 154 problem was primarily a matter of adhesives.

As Robert points out the majority of workers in any manufacturing industry are not 'craftsmen', retraining metal aircraft assemblers
as wood-aircraft assemblers would not be difficult and production output could, theoretically, actually be greater because the wood
technology actually requires less in the way of equipment and space.

I've worked on and around aluminum airframes (electrician on Sikorsky S-61, various Bell, Boeing electrical design)
and built custom cold-moulded ply wooden-boats and from my own experience people experienced in one would
have no problem switching to the other.

As to a metal Mossie equivalent, well De Havilland designed and built the all-metal DH 95 before the war so they could
simply have done the DH 98 in aluminum, barring that, the closest would probably be something based on the
Gloster F.9/37.

http://www.whatifmodelers.com/index.php/topic,21240.0/highlight,gloster.html


Jon

[Weaver]

My brother can tell you horror stories from his time on the 777 (as an actual licensed A&P he could only deal with it for two years) line where you had guys who figured  "jigs? jigs? we don need no stinkin' jigs" or drill guides, with, as you'd expect, the predictable result of expensive parts being screwed up. Usually the violators were the longest term and, supposedly, most experienced aka skilled hands. Of course there is a difference between fifteen to twenty years experience in a given field and doing the same task for fifteen to twenty years.

Jon

Oh yeah - I work in an aircraft factory and the old sweats can be the worst:


"I've been doing it this way for twenty years so it must be right!"

"But we've changed it: now you got to do it differently..."

"But I've been been doing it this way for twenty years!"

"But we've changed it..."

"But...."   


Oner of the most annoying things is when you tell an apprentice to do the right thing and they accept it, and then their "gaffer" tells them to do the wrong thing instead "because that's how we've been doing it for twenty years...." 

[jcf]

Oh yeah - I work in an aircraft factory and the old sweats can be the worst:


"I've been doing it this way for twenty years so it must be right!"

"But we've changed it: now you got to do it differently..."

"But I've been been doing it this way for twenty years!"

"But we've changed it..."

"But...."   


Oner of the most annoying things is when you tell an apprentice to do the right thing and they accept it, and then their "gaffer" tells them to do the wrong thing instead "because that's how we've been doing it for twenty years...." 

Unfortunately its not limited to the factory floor, I encountered exactly the same thing when I worked electrical design at Boeing (747, 737-AEW&C, 777 and 787). 

Some days I wanted to strangle someone. 

Jon