16 replies to this topic

[Philip Whiteman]

Setting aside the car books for a moment (including Jack Brabham's super new autobiog, done with with Doug's help), I was looking at an older volume about the great Hugo Junkers. Produced in what was East Germany, this book details Junkers' pioneering work on aero diesels and metal structures. Particularly impressive were the D7 and D9 fighter planes - very modern-looking cantilever monoplanes (no bracing wires) with stressed-skin fuselage structures, seatbelts and even a roll-over hoop: 1960s Grand Prix car technology some 40 years before motor racing people took it up in earnest.

Even my Piper Cub - a 1930s design - has a welded steel space-frame of the type that didn't see use in Grand Prix cars until the early 1950s.

It seems very odd that proven concepts for light, stiff structures - not to mention elementary safety measures - should take so long to be adopted by one industry from another.

We all know the great influence ex-Bristol Aircraft Company and ex-de Havilland people had on motor racing (think Malcolm Sayer and the D-Type Jaguar and Frank Costin and the Vanwall). My question is; does the 'technology transfer' essentially have to wait until people - especially engineers - actually move from one sphere to another? Why do ideas either fail to migrate or take so long in doing so?

[xkssFrankOpalka]

I agree, race car designers should read the aircraft mags to keep abreast of the latest trends in aircraft to see what they can apply to the race cars.

[Arthur Anderson]

Originally posted by Philip Whiteman
Setting aside the car books for a moment (including Jack Brabham's super new autobiog, done with with Doug's help), I was looking at an older volume about the great Hugo Junkers. Produced in what was East Germany, this book details Junkers' pioneering work on aero diesels and metal structures. Particularly impressive were the D7 and D9 fighter planes - very modern-looking cantilever monoplanes (no bracing wires) with stressed-skin fuselage structures, seatbelts and even a roll-over hoop: 1960s Grand Prix car technology some 40 years before motor racing people took it up in earnest.

Even my Piper Cub - a 1930s design - has a welded steel space-frame of the type that didn't see use in Grand Prix cars until the early 1950s.

It seems very odd that proven concepts for light, stiff structures - not to mention elementary safety measures - should take so long to be adopted by one industry from another.

We all know the great influence ex-Bristol Aircraft Company and ex-de Havilland people had on motor racing (think Malcolm Sayer and the D-Type Jaguar and Frank Costin and the Vanwall). My question is; does the 'technology transfer' essentially have to wait until people - especially engineers - actually move from one sphere to another? Why do ideas either fail to migrate or take so long in doing so?

Philip,

For starters, a Monocoque (and by that, I mean fully monocoque) race car body/chassis WAS built, and raced, in 1915! This car, the Cornelian, was designed and built by none other than Louis Chevrolet, and was driven by him in the 1915 Indianapolis 500 Mile Race. I have seen this car (didn't even imagine it still existed!) up close, and I can tell you, there is not one iota of any frame rails, nor even any tubular structure, but a formed sheet-aluminum body, much like an aluminum, stressed skin aircraft (say, like a Cessna or modern Piper). In addition, this car has fully independent suspension on all 4 corners, made up of twin transverse leaf springs, one above the other, with the hub carriers attached between them. Sound familiar? It should--in the 1950's, IIRC, this style was termed the "Tojeiro Suspension" after the assumed inventor of it (although Willys-Overland and Studebaker used a very similar independent front suspension system--Studebaker in 1939-46 on the Champion, Willys on the 1948-65 2wd Jeep station wagon--both makers termed it "Planar Suspension"), but it was first used on a race car in 1915.

On your other comments: Tubular space frames, be they aircraft or automotive, rely on welding, be that acetylene torch, carbon-arc, arc-welding, or the more modern welding technologies. In the 'teens' and through the 1930's, the welding of steel, particularly under high-stress conditions, was still very much an untried technique, certainly in automotive applications. Look at the chassis of any production car built prior to WW-II, and you will see rivets galore, and nary a weld. Even naval construction avoided welding altogether until the tremendous necessity of rapid construction of ships virtually mandated the development of reliable welding equipment and techniques. Yet still, in steel construction (buildings, bridges, etc.) the preferred method of attachment and the joining of structural steel members is still either riveting or bolting.

Tubular space frames for race cars was something not for the faint of heart to be the first to try it, however, I believe that the Marchese Brothers built at least one Indianapolis car prior to WW-II with a welded tubular space frame. It remained until after WW-II, and Frank Kurtis' highly successful midgets and sprint cars, for welded space frame chassis to become not only acceptable, but dominant. Also, these chassis were far more expensive than the old-style channel frames. Equally, a formed sheet metal monocoque "tub" was more expensive to construct than a space frame (and much harder and more expensive to repair after a crash). Car owners and constructors had not the money available (either theirs, or sponsorship money) to make those seemingly quantum leaps into new chassis construction techniques--that is something that took time.

In American racing, seat belts came into use in the 1930's, and, just as is still the case today with ordinary street drivers, there were many race drivers who insisted upon their having a greater chance of surviving a crash if they could but be thrown out of the car before it landed on them. Hard helmets came into racing before they were standard issue in flying--H O D Segrave, the Land Speed Record driver tried one, then gave a similar helmet to Wilbur Shaw, who is the first recorded user of a crash helmet at Indianapolis--in 1932, but still, there were those who scoffed at such a notion, well into the late 1930's. Rubber fuel cell liners reached auto racing after the tragic and fiery season of 1964--really not all that much later than their introduction into military aircraft.

The roll bar is something that took far longer than it should have to reach motorsports, certainly in the US--USAC didn't require a true roll bar until after the horrendous 1st lap crash at Indianapolis in 1958, in which popular driver Pat O'Connor was killed almost instantly when his car landed upside down, the only hint of a roll bar being the support tube structure inside the headrest fairing behind the cockpit.

I hope this helps clear up some of this. But, keep in mind, motor racing has pretty much always been a private, civilian sport--and as such, not until fairly recent times have race car designers, constructors, or car owners had the money needed to adapt ever-higher tech ideas to their cars.

Art

[T54]

I have seen this car (didn't even imagine it still existed!)

Is not the Cornelian currently seen a replica built from old pictures and plans? I was under that impression.

[Eric McLoughlin]

These days, there is arguably more money available in F1 for innovative technology than there is in the aviation/aerospace industry. The fact that NASA have recently been working with McLaren on the construction of composite chassis designs for Mars Rovers shows where a lot of the engineering talent now lies.

Up to the most recent decades, aerospace led the way.

[Arthur Anderson]

Originally posted by T54


Is not the Cornelian currently seen a replica built from old pictures and plans? I was under that impression.

The car is currently on display in the Gilmore Car Museum at Hickory Corners, Michigan. Nothing about the display indicates anything about its being a "replica" (as does for example, the 1911 Model T Ford race car "999-II" which is clearly designated a replica by the story board next to it--an exacting replica of the actual, Frank Kulick-built and driven 1911 car). I wish I'd taken a picture of the story board for the Cornelian, as it indicates that the was found locally (the Gilmore Museum is just 10 miles northeast of Kalamazoo, and Cornelian was a short-lived company in Kalamazoo trying to enter the "cycle car" segment of the car market in 1915).

Given that the Gilmore Museum is, I believe, quite knowledgeable about the cars they own, and those that are loaned for display, and that they also have a very high reputation for accurately presenting their exhibits, I suspect that were this car a total replica, they would indicate such.

Also, I'm not at all sure that much would have existed in the way of drawings, even pictures--are there any pictures of the car out there other than the one "official" qualifying photograph from Indianapolis? I've never seen anything other than that. Somehow, I don't think Louis Chevrolet was much of a draftsman, although the Cornelian company probably did have one. However, my sense of this leads me to wonder how much of that might have survived over the years--the American automotive landscape is dotted with the burial sites of several thousand makes of cars, the vast majority of which disappeared virtually without a trace, beyond a stray extant example here and there.

A couple of years ago, there was a website devoted to the Cornelian, it would be interesting to see if it is still up (or anything like it). Later today, I'll do a Google search, see what I can find on it.

Still, this does not diminish the pioneering effort of this car: Even if a replica, the actual car did have the characteristics that I mentioned earlier: Monocoque chassis/body, and 4-wheel independent suspension.

Art

[T54]

I read a whole story about the car not too long ago, and it was mentioned that the car was in fact a replica of the long-disappeared original. But I could be wrong and my memory is cloudy, this is why I was asking. In any case, a fine effort of applying aircraft tech to racing application. What was next, the 1923 Voisin? Trimax?
Regards,

T54

[Arthur Anderson]

Originally posted by T54


I read a whole story about the car not too long ago, and it was mentioned that the car was in fact a replica of the long-disappeared original. But I could be wrong and my memory is cloudy, this is why I was asking. In any case, a fine effort of applying aircraft tech to racing application. What was next, the 1923 Voisin? Trimax?
Regards,

T54

Regardless of whether the extant Cornelian is the original car, or not, I don't think it changes what I wrote about the car, it's salient features, and the year in which those design features were created.

Of course, that assumes that if a replica, it is an accurate portrayal. I cannot imagine anyone laying out the considerable money to totally replicate this car, if every component and assembly had to be made completely from scratch--the cost would be tremendous indeed. For example, to illustrate: Starting in mid-2000, Ford Motor Company set out to build 6 brand-new 1914 Model T touring cars (1914 being the first production year of Model T Fords -- or for that matter any automobile -- on a modern assembly line conveyor from raw material to finished car--hence the significance) for the company's Centennial celebration in 2003. All the formed, stamped sheet metal parts were created from new tooling (body, hood, radiator, fenders, splash aprons, running boards, frame members, radius rods), while every casting or forging was created new, using pristine original parts as masters (the forged front axle, rear axle and suspension forgings) for investment casting in steel, complex castings such as the engine, oil sump, transmission housing were literally sawed up, to gain access to internal cavities from which casting patterns (cores) could again be made. The various body stampings (fenders, running boards, splash aprons, hood and body shell) were created from newly made "Kirksite" dies (very commonly used for short-run stampings such as this), the body wood was recreated from pristine original parts. The total cost was estimated (publicly) to have been almost $1,000,000 for 6 cars, and I would bet that at least 75% of that was in created the first set of parts and components.

My guess would be, that if the Cornelian race car is indeed a replica, that the restorer surely must have started with some existing parts such as the engine, transmission, differential, and the various other parts and pieces, otherwise the project would have cost a mint big enough to have daunted just about any restorer/enthusiast. I believe the storyboard in front of the car mentions that it "was found" in a barn or warehouse either in or near Kalamazoo. It could be that what was found were parts enough to have been the basis for replicating the chassis/body.

I'd seriously wonder if any drawings were ever made of the racecar project itself in 1915, simply because by most accounts, Louis Chevrolet was pretty much a "cut & fit" builder, much like so many "small operators", but then I could be wrong. The unsophisticated shapes of the bodywork would seem to make this a possibility, there being very, very little there that couldn't have been done on common bending and rolling brakes by anyone versed in sheet metal fabrication/
construction. The radiator shell appears to be about the only exception to this idea, and perhaps even that was intended to be a production shell, had Cornelian actually produced any cars for sale.

The car is small, very small indeed, for a pre-WW-I race car. The radiator and hood are barely 36" high, the track-base probably no wider than that of a Model T (incidently, the standard track of a Model T Ford was 56", the same as the vast majority of horsedrawn vehicles, the legend being also that this is the same track as horsedrawn vehicles in Europe, going back to Roman times)

The size of the Cornelian is very much in keeping with the "Cyclecars" of the years just prior to WW-I. No more than 25' from where the Cornelian is standing at the Gilmore, there is a 1914 Woods Mobilette Cyclecar, which is very nearly the same size, being perhaps 12" narrower in track, and using a much larger wheel diameter than the Cornelian.

I seem to recall reading that the Cornelian was constructed, and raced, in the hope that a strong finish (I wonder what the parameter was there!) at Indianapolis would attract investment capital to proceed with a production car. Of course, that wasn't to be, and Cornelian seems to have disappeared very soon after.

Another thought: In decades past, at least in the US, when small companies failed, often nobody cared much to keep any of the artifacts for future reference--often not even the financial records exist, except as scraps of information, tax regulations being almost non-existent back then, and if there was nobody seriously interested in archiving and maintaining those drawings, records etc., then as the years went by, they simply tended to disappear.

Art

[T54]

I cannot imagine anyone laying out the considerable money to totally replicate this car, if every component and assembly had to be made completely from scratch--the cost would be tremendous indeed.

Not really... it is a rather simple car with no complex shapes, no compound curves anywhere except may be on the top of the cowling, with engine components that are relatively available if one digs a bit. I seem to remember that the fellow had similar or identical mechanical components to the original and started from there.
I reckon that he could have spent $60K/$75K, I don't see that much more in the car.
Cute bugger regardless.

T54

[dosco]

Originally posted by Philip Whiteman
It seems very odd that proven concepts for light, stiff structures - not to mention elementary safety measures - should take so long to be adopted by one industry from another.

My question is; does the 'technology transfer' essentially have to wait until people - especially engineers - actually move from one sphere to another? Why do ideas either fail to migrate or take so long in doing so?

Wow, excellent question.

When you look at the early aviation industry, you have to keep many things in mind. First, the first examples of aircraft were wooden spar-and-frame deals that were wire braced. Additionally, the manufacturing technology of the day was woefully lacking (perhaps an understatement considering the participants of this BB)....so to readily/easily enter the aircraft building business, you could grab a bunch of boat and furniture builders, and have at it posthaste.

To go with a semi- or full monocoque design required manufacturing skills and materials that had to be developed from scratch (keep in mind that many manufacturing techniques are evolutionary steps from previously mastered techniques). With that said, there were a few standouts in the early aviation days....Anthony Fokker's team was able to master steel tube construction (which was a design element featured on most if not all of his production aircraft) and the Albatros-Werke who made the wooden monocoque for their D.Va and Scout aircraft. Simplistically speaking, the rest of the manufacturers used various versions of the wood-strut-and-wire approach.

The semi-monocoque metal aircraft wasn't really accepted by the aviation industry until perhaps the mid to late 1920s.....for a variety of reasons, though my personal opinion is that it had more to do with metal alloy systems than anything else (high-quality aircraft aluminum wasn't readily available until this time period). I suppose part of the reluctance to accept this style of construction was the engineering personnel needed to design such aircraft (not a lot in the early 1900s) and the "momentum" of the accepted methods of wood and fabric.

OTOH, I have noticed the reluctance to accept other technologies/crossover myself......seems that many engineering types grow up in a "stovepipe" and don't experience a lot of other "technical fields." I'm a race enthusiast, model airplane enthusiast, rocketry enthusiast....all of which drove me into an engineering career - all the while I work with people who are ignorant of all sorts of technology - they seem to have blinders on. Very interesting phenomena.

[Arthur Anderson]

Originally posted by dosco


Wow, excellent question.

When you look at the early aviation industry, you have to keep many things in mind. First, the first examples of aircraft were wooden spar-and-frame deals that were wire braced. Additionally, the manufacturing technology of the day was woefully lacking (perhaps an understatement considering the participants of this BB)....so to readily/easily enter the aircraft building business, you could grab a bunch of boat and furniture builders, and have at it posthaste.

To go with a semi- or full monocoque design required manufacturing skills and materials that had to be developed from scratch (keep in mind that many manufacturing techniques are evolutionary steps from previously mastered techniques). With that said, there were a few standouts in the early aviation days....Anthony Fokker's team was able to master steel tube construction (which was a design element featured on most if not all of his production aircraft) and the Albatros-Werke who made the wooden monocoque for their D.Va and Scout aircraft. Simplistically speaking, the rest of the manufacturers used various versions of the wood-strut-and-wire approach.

The semi-monocoque metal aircraft wasn't really accepted by the aviation industry until perhaps the mid to late 1920s.....for a variety of reasons, though my personal opinion is that it had more to do with metal alloy systems than anything else (high-quality aircraft aluminum wasn't readily available until this time period). I suppose part of the reluctance to accept this style of construction was the engineering personnel needed to design such aircraft (not a lot in the early 1900s) and the "momentum" of the accepted methods of wood and fabric.

OTOH, I have noticed the reluctance to accept other technologies/crossover myself......seems that many engineering types grow up in a "stovepipe" and don't experience a lot of other "technical fields." I'm a race enthusiast, model airplane enthusiast, rocketry enthusiast....all of which drove me into an engineering career - all the while I work with people who are ignorant of all sorts of technology - they seem to have blinders on. Very interesting phenomena.

Very good answer!

We do need to take into account that the technologies of both flying, and building ever-faster race cars both were pushing the envelope in the 1st 30 years or so of both pursuits, while simultaneously the basic metals industries were still learning how to make better and more workable steels (which ultimately would allow much lighter, yet stronger components made from steel), and the aluminum industry was still quite young.

You wisely point out the infancy of the light alloys available in the 1920's, along with the continued reliance on wood as a material for framing up aircraft wings and fuselages. What is forgotten by so many, however, is the simple fact that during most of the 1920's, the aircraft industry, certainly in the US, was hampered extremely by the ready availability of WW-I surplus planes, such as the Curtiss JN4 "Jenny", and the DeHavilland DH4, both of which were in greater supply than pilots to fly them for a fair number of years. This situation alone served to keep the struggling aircraft industry from any serious growth (many of them failed, the others struggled to survive) due to the stocks of these surplus planes driving down the market (very much the same as if there had been a huge surplus of low-mileage used cars (what effect that would have had on the market for new ones?). Given the much higher cost of not only designing new, state-of-the-art all metal planes (and by the way, Ford Motor Company did commission Bill Stout to do just that--end result: The famed and durable Ford Trimotor series of airliners). Military development, which might have spurred civilian offspring, was nearly non-existent, both here in the US and abroad--Germany forbidden to have an aircraft industry building powered aircraft, France & Britain exhausted physically and financially from the Great War, and the US Government convinced there would never be another war, at least not in the foreseeable future (and seeing aircraft as expensive playthings).

Interestingly, it was racing, the racing of airplanes, that by the late 20's, spurred the early development of things such as all metal monoplanes with cantilever wings, monocoque fuselages.

As for the "safety" ideas that Junkers and others designed into aircraft, these were developed for other reasons than their adoption in motor racing. Once airplanes became "aerobatic" as fighter planes in WW-I, capable of flying inverted and level, something had to be provided to keep the pilot in his seat while upside down (not a cool thing to roll your plane on its back, only to fall out!), so the rudimentary seat belt was born--at first, simple leather belts, with buckles very much like the buckles that hold the belts together that keep our pants from falling down--the quick-release buckle came later.

The so-called "rollover hoop" installed on early aircraft was more to enable the pilot to extricate himself from an upside-down aircraft in case of nosing over in a bad landing as anything else--after all, surrounded by probable leaking gasoline tanks, an unfortunate pilot needed the cockpit pylon to give him a chance to escape--but it wouldn't have been of much help (and in fact, they weren't much protection at all) in a high-velocity crash, simply because airplanes seldom roll over in the manner of an out-of-control race car.

In race cars having minimal bodywork, or having a fairly large cockpit opening, absent seatbelts, the chances of the driver being crushed under his car in a crash were greatly lessened by his being pitched free and clear of a flipping, tumbling machine--of course, only to face other, potentially greater injuries.

In racecar construction, the tubular space frame, as built by Junkers in 1918, may well not have withstood the much higher vibration, not to mention possible impacts, in a race car, simply due to the welding technology of the day, which was also in its infancy. Even if the joints had been brazed, then the most common method of creating high-strength joints between metal parts without rivets or bolts, has its limits as well. The stresses on a plane flying at no more than perhaps 150mph, even when dog-fighting, surely pale in comparison to similar stresses in a race car at speed, certainly on the rough race courses predominant back then, outside of the smooth as glass board speedway. Add to all of this, even in the 30's and 40's that welding by most metal workers was still a bit of a "black art", even exotic, until trained expert welders graduated from the various war industries at the end of the Second World War.

Anyway, it's always good to look back, and say "why not", and then take a hard look at the history, and see why the "not" almost had to be.

Art

[Wuzak]

Who created the first production monocoque car and when?

I have a vague recollection that Lancia made its first monocoque production car in around 1919. Is this correct?

[dosco]

Originally posted by Arthur Anderson
You wisely point out the infancy of the light alloys available in the 1920's, along with the continued reliance on wood as a material for framing up aircraft wings and fuselages. What is forgotten by so many, however, is the simple fact that during most of the 1920's, the aircraft industry, certainly in the US, was hampered extremely by the ready availability of WW-I surplus planes, such as the Curtiss JN4 "Jenny", and the DeHavilland DH4, both of which were in greater supply than pilots to fly them for a fair number of years.

Military development, which might have spurred civilian offspring, was nearly non-existent, both here in the US and abroad--Germany forbidden to have an aircraft industry building powered aircraft, France & Britain exhausted physically and financially from the Great War, and the US Government convinced there would never be another war, at least not in the foreseeable future (and seeing aircraft as expensive playthings).

Interestingly, it was racing, the racing of airplanes, that by the late 20's, spurred the early development of things such as all metal monoplanes with cantilever wings, monocoque fuselages.

Good points - hadn't thought of the surplus problem.....although there were many planes designed and built in the late 20s/early 30s, it may be fair to say the surplus market could have had an influence on the industry as a whole.

Another excellent point is the military - little to nothing was being done by the US military in these years.....hell, Billy Mitchell had one heck of a time convincing anybody in D.C. that strategic bombing was of any worth.

I'm not sure it's fair to say that Germany was out of the picture after WW1, though - they developed all kinds of military aircraft under the guise of "civilian transport" - the aircraft were then tested during the Spanish civil war.

In racecar construction, the tubular space frame, as built by Junkers in 1918, may well not have withstood the much higher vibration, not to mention possible impacts, in a race car, simply due to the welding technology of the day, which was also in its infancy.

I'd have to take issue with that.

The mass of a rotary engine is far greater than any racing engine back in the day (or any modern engine save a racing truck or diesel locomotive - LOL). Additionally, the fact that the crank was affixed to the fuselage meant that a rather large gyroscopic force was applied to the aircraft as a reaction to any flight maneuver. Also, the rotary engines didn't have any throttling, so they were "on/off" affairs which undoubtedly put harsh stresses on the fuselage.

The stresses on a plane flying at no more than perhaps 150mph, even when dog-fighting, surely pale in comparison to similar stresses in a race car at speed, certainly on the rough race courses predominant back then, outside of the smooth as glass board speedway.

You can pull several "Gs" in many WW1 aircraft (a SPAD 13 could safely dive at well over 250 mph), Can you do the same in a vintage race car?

I'll give you the rough roadway part, though....

[soubriquet]

Originally posted by Wuzak
Who created the first production monocoque car and when?

I have a vague recollection that Lancia made its first monocoque production car in around 1919. Is this correct?

From memory, the first Lancia to have a monocoque was the Lambda. From the early 1920s.

Cheers
S

[Arthur Anderson]

Originally posted by soubriquet


From memory, the first Lancia to have a monocoque was the Lambda. From the early 1920s.

Cheers
S

Come to think of it, while not a production car per se', wasn't the 1904 Stanley Land Speed Record car (the "wogglebug") essentially a monocoque body?

It seems that I have some pictures around here someplace, of the car before and after it's horrific crash at Ormond Beach, and no evidence of any separate frame? I could be wrong, but it seems to me that it appeared to have been built from wood, with the boiler installed inside, and the steam engine/rear axle and front axle with springs attached to what was essentially a unit body.

Can anyone confirm this?

Art

[Macca]

Regarding WW1 aircraft; IIRC the German Junkers company were the first to come up with a metal-skinned cantilever low-wing monoplane (as opposed to cantilever high-wing or parasol-wing aircraft with wood-frame or tubular fuselages) but the metal skin had to be corrugated to give enough strength. Maybe they had it patented, so with no German aircraft in the 1920s no-one else could copy it, or maybe it was just a dead-end.

The main, if not the first, monocoque fighting aircraft of WW1 was the Albatross D-series of fighters which had two layers of staggered or crossplied glued veneer ('double-diagonal' in boatbuilding terms) which was a common boatbuilding technique for racing yachts even then, although the glue wasn't much good and didn't last (WW2 was when modern durable glues were developed, and used in the Mosquito aircraft).

Again maybe it was a dead-end with the technology of the time, or the durability was limited which meant it was only suitable for the limited life of a front-line fighter in a war situation, or maybe it was too difficult to maintain or repair (eg bullet-holes).


Paul M

[Arthur Anderson]

Originally posted by Macca
Regarding WW1 aircraft; IIRC the German Junkers company were the first to come up with a metal-skinned cantilever low-wing monoplane (as opposed to cantilever high-wing or parasol-wing aircraft with wood-frame or tubular fuselages) but the metal skin had to be corrugated to give enough strength. Maybe they had it patented, so with no German aircraft in the 1920s no-one else could copy it, or maybe it was just a dead-end.

The main, if not the first, monocoque fighting aircraft of WW1 was the Albatross D-series of fighters which had two layers of staggered or crossplied glued veneer ('double-diagonal' in boatbuilding terms) which was a common boatbuilding technique for racing yachts even then, although the glue wasn't much good and didn't last (WW2 was when modern durable glues were developed, and used in the Mosquito aircraft).

Again maybe it was a dead-end with the technology of the time, or the durability was limited which meant it was only suitable for the limited life of a front-line fighter in a war situation, or maybe it was too difficult to maintain or repair (eg bullet-holes).


Paul M

Paul,

I would imagine that during WW-I, molded plywood would have been fairly durable, especially if it had been adapted to marine use--it's immersion in water that is a real enemy of laminated, glued wood. However, weren't most racing yachts still built with more conventional "plank on frame" through the eve of the Great War? As for it being "failed technology" see the next paragraph. I suspect that it was more an attempt to build a tougher, even faster airplane than was possible with the then-conventional fabric covering over wood framing. Also, aluminum was still a metal in fairly short supply, the industrial base for producing it in vast quantities only beginning to develop by 1914, and certainly Germany, given the blockade of maritime commerce, would have found it difficult to obtain bauxite (aluminum ore) in any great quantity, given that most of that would have come from either Africa or Central-South America. Britain faced similar obstacles during WW-II, but not to the extent that Germany would have.

I wouldn't forget the Lockheed Sirius (low-wing monoplane with cantilevered wing) and the Lockheed Vega (high-wing version of the same aircraft), both of which were built with laminated veneer. The biggest problem with this material, beyond maintenance, probably was cost--hand-laid "molded plywood" had to have been labor-intensive. Lockheed's idea (was probably was Junkers' as well) was to build, first of all, a wing with a consistent airfoil, which wasn't truly possible with the then-conventional "fabric over rib" construction, given that the fabric sags between the wing ribs.

William B. Stout, in the mid-1920's, began building a series of high-wing monoplanes, culminating in the famous tri-motored Ford 5-AT series, which also used corrugated aluminum on all surfaces, save for the controll surfaces, which were still fabric covered. Junkers, at about the same time, began construction of their famous tri-motored planes, which culminated in the Ju-52. Douglas Aircraft Company also used corrugated wing and tail surface covering in their series of observation aircraft, and the TBD-1 Devastator torpedo plane of tragic history at Midway. Martin used corrugated aluminum wing skin on the B-9 and B-10 twin engine bombers of the mid-1930's.

DeHavilland, did they not, created the Mosquito out of molded plywood, primarily due to the shortage of aluminum in Britain during the war?

Art