Why the heck did they design it that way?

[pbehn]

It is a bit difficult trying to condense several hundred pages worth of aviation fuel history into a few paragraphs. but yes, it was extremely difficult. It got much harder as the demand for fuel skyrocketed and choices had to be made about allowable levels of both lead and aromatic compounds in fuel as opposed to the amount of steel and building requirements needed by refineries to manufacture the needed fuel, one change in lead allowed was supposed to have saved enough steel to build ten destroyers if I remember right. The piping in refineries being a higher grade steel than freighter hulls.

Anda s most planners, they were trying to think 6 months to year ahead and not react to a shortage this week or next.

I fully understand the concept if not the detail S/R, I worked for years on mechanically and metallurgically bonded oil/gas pipes. These cost much more than plain high yield carbon steel, but save a fortune on corrosion inhibitors, putting them in and taking them out. It is all much much more complicated than a single post can explain.

 

[michael rauls]

Another interesting pick for"why the heck did they design it that way" is the p47 and its limited range. I know extra fuel is extra wieght and therefore degrading of performance but it seems if ever there was a plane with the space, need, and a little performance to spare especially at high altitude it was the p47. This one is a real head scratcher for me.

 

[MiTasol]

The British air ministry (or the dolt in charge of propellers) should have been summarily shot for either treason or criminal malfeasance.

Years ago (about 1973) I bought a book on the history of the guns of the RAF. I have been trying to find a replacement copy for the last ten years.

According to it many of the directives regarding aircraft guns were made, not by the RAF experts but by Army experts. And that these experts grounded all the canon armed Spitfires for a few days early in the BoB until Hispano could prove that the breach was locked when the gun fired because the army prohibited the use of blowback weapons.

One of the lines I remember from the book is that these very modern up to date policy wonks made the statement "there is a place for cavalry in modern warfare so long as it is thoroughbreds ridden by gentlemen" in early 1939. These same wonks ensured the 1939 budget contained more money for hay for horses than fuel for vehicles, tanks, etc.

If this is correct it is not surprising that the RAF were against constant speed props and other non-British inventions. Don't forget the original Spitfire had fixed landing gear.

To quote Wiki In 1931 the Air Ministry released specification F7/30, calling for a modern fighter capable of a flying speed of 250 mph (400 km/h). R. J. Mitchell designed the Supermarine Type 224 to fill this role. The 224 was an open-cockpit monoplane with bulky gull-wings and a large, fixed, spatted undercarriage powered by the 600 horsepower (450 kW), evaporatively cooled Rolls-Royce Goshawk engine.[5] It made its first flight in February 1934.[6] Of the seven designs tendered to F7/30, the Gloster Gladiator biplane was accepted for service.[7]

Across the pond Donald Douglas started design of the DC-1 at the same time and the prototype made its maiden flight on July 1, 1933 - eight months before the Supermarine 224. The DC-1 had all metal structure, retractable gear and variable pitch props and was only 40mph slower than the 224 - and also carried 15 persons in a fully enclosed cabin. Boeing's competing model 247 was also all metal, retractable and fitted with variable pitch propellers.

Britain's top line fighter chosen that year was the fixed gear, fixed pitch and fabric covered Gladiator biplane.

 

[Shortround6]

Another interesting pick for"why the heck did they design it that way" is the p47 and its limited range. I know extra fuel is extra wieght and therefore degrading of performance but it seems if ever there was a plane with the space, need, and a little performance to spare especially at high altitude it was the p47. This one is a real head scratcher for me.

It is not a head scratcher, it is a change in operational requirements. The P-47 was NOT designed as a long range escort fighter.
And with the original 305 gallons internal the P-47 could fly roughly twice as far as a Spitfire or 109 at similar speeds and altitudes.
It turned out that when the plane went into service nearly 3 years after initial design work started even that range was nowhere near enough.
The P-47 could fly roughly the same distance at the same speed and altitude as a P-40 with the P-40 having a full behind the seat tank which was an overload tank. Not to be fully filled when doing maneuvers.

 

[pbehn]

Another interesting pick for"why the heck did they design it that way" is the p47 and its limited range. I know extra fuel is extra wieght and therefore degrading of performance but it seems if ever there was a plane with the space, need, and a little performance to spare especially at high altitude it was the p47. This one is a real head scratcher for me.

Is there an aeroplane whose range was satisfactory, one that the P-47 should have been designed to match?

 

[Shortround6]

Years ago (about 1973) I bought a book on the history of the guns of the RAF. I have been trying to find a replacement copy for the last ten years.

According to it many of the directives regarding aircraft guns were made, not by the RAF experts but by Army experts. And that these experts grounded all the canon armed Spitfires for a few days early in the BoB until Hispano could prove that the breach was locked when the gun fired because the army prohibited the use of blowback weapons.

One of the lines I remember from the book is that these very modern up to date policy wonks made the statement "there is a place for cavalry in modern warfare so long as it is thoroughbreds ridden by gentlemen" in early 1939. These same wonks ensured the 1939 budget contained more money for hay for horses than fuel for vehicles, tanks, etc.

If this is correct it is not surprising that the RAF were against constant speed props and other non-British inventions. Don't forget the original Spitfire had fixed landing gear.

To quote Wiki In 1931 the Air Ministry released specification F7/30, calling for a modern fighter capable of a flying speed of 250 mph (400 km/h). R. J. Mitchell designed the Supermarine Type 224 to fill this role. The 224 was an open-cockpit monoplane with bulky gull-wings and a large, fixed, spatted undercarriage powered by the 600 horsepower (450 kW), evaporatively cooled Rolls-Royce Goshawk engine.[5] It made its first flight in February 1934.[6] Of the seven designs tendered to F7/30, the Gloster Gladiator biplane was accepted for service.[7]

Across the pond Donald Douglas started design of the DC-1 at the same time and the prototype made its maiden flight on July 1, 1933 - eight months before the Supermarine 224. The DC-1 had all metal structure, retractable gear and variable pitch props and was only 40mph slower than the 224 - and also carried 15 persons in a fully enclosed cabin. Boeing's competing model 247 was also all metal, retractable and fitted with variable pitch propellers.

Britain's top line fighter chosen that year was the fixed gear, fixed pitch and fabric covered Gladiator biplane.

I can forgive the Supermarine type 224

as at the time nobody else was using retractable landing gear either except the Russian I-16 and the Russians weren't talking.
While this flew in 1932 it wasn't placed in Squadron service until 1935.

In the case of the Supermarine aircraft we have another case of officials screwing things up. The AIr Ministries "preferred" engine was the RR Goshawk. From wiki so usual disclaimer.
"Specification F.7/30, which was formally issued to the aircraft industry in October 1931, called for an all-metal day and night fighter armed with four machine guns, a high top speed and rate of climb, and a landing speed of less than 60 mph. The importance of a good view from the cockpit was made clear. Although the use of any power plant was permitted, the Air Ministry did express a preference for the evaporatively cooled Rolls-Royce Goshawk then being developed."

The Goshawk engine was a Kestrel that was modified for 'evaporative cooling'. The water was allowed to turn to steam and was then condensed back to water.
This was supposed to allow for a lighter, more effective cooling system but it never worked and doomed any plane that used it to either failure or major rebuild.
The Choice of the Gladiator was the result of the 4 aircraft using the Goshawk engine all failing. That and the Gladiator could be built using some of the tooling from the Gauntlet so it could be produced quickly after the long delay in coming up with a replacement for the Bristol Bulldog.

First flown 1927, into service in 1929 and still equipping 8 of the RAFs 14 fighter squadrons in Jan 1935.
If they had let the designers/manufacturers use a normal Kestrel things might have gone quicker.

 

[michael rauls]

Is there an aeroplane whose range was satisfactory, one that the P-47 should have been designed to match?

No not nescesarily. Just a curiosity hence the question. I guess the answer in the case of the p47 is more that the need for more range sprang up later and wasn't know at the time of development as opposed to the bf109 and spitfire which were a combination of this and space, wieght limitations, and possibly cog/stability issues with a larger tank if I understood everyones responses corectly.
That's what's interesting, at least to me, the why of why were things designed the way they were. That is why I started this thread. To satisfy the curiosity of those of us who don't know or think we may know but aren't sure and provoke interesting conversation and debate among those of you more knowledgeable.
It's also just a coincidence my two original and this pick involve range. Could be any feature, good or bad and I would truly love to here some others ideas or questions of why things were thhe way they were. That's one of thee things that make this all interesting. At least in my opinion.

 

[michael rauls]

Hey look everyone, paragraphs. I found the enter button at last .

 

[Shortround6]

No not nescesarily. Just a curiosity hence the question. I guess the answer in the case of the p47 is more that the need for more range sprang up later and wasn't know at the time of development as opposed to the bf109 and spitfire which were a combination of this and space, wieght limitations, and possibly cog/stability issues with a larger tank if I understood everyones responses corectly.
That's what's interesting, at least to me, the why of why were things designed the way they were. That is why I started this thread. To satisfy the curiosity of those of us who don't know or think we may know but aren't sure and provoke interesting conversation and debate among those of you more knowledgeable.
It's also just a coincidence my two original and this pick involve range. Could be any feature, good or bad and I would truly love to here some others ideas or questions of why things were thhe way they were. That's one of thee things that make this all interesting. At least in my opinion.

I also like finding out why things were done the way there were done.
Fighter aircraft, especially in the late 1930s were pretty tight aircraft in the design sense. There is not a lot of extra weight to fool around with even if there was extra volume in the fuselage. You have to have the center of gravity right. To get good speed and climb you have to keep the payload small.

A really good designer ties to anticipate future needs/growth rather than make a plane too tight but their crystal balls only work so well.
Somebody was smart enough on the Spitfire to put ballast weights in or on the engine mounts of the planes with the two blade wooden propellers so when they were changed to to the variable pitch props the weights could be removed and the plane's CG stayed pretty much the same,. One reason for NOT sticking fuel tank/s behind the seat on the early planes.
By the time you get to the MK IX with the two stage Merlin the Spitfire was carrying five 17.5lb weights in the tail to help balance the heavier engine and prop, this is addition to the bigger radiators/intercoolers being mounted just behind the CG.
Of course this means the MK IX was carrying 87.5 lb of pig iron that did nothing for strength or endurance or firepower or.............

Other planes did some similar things. Bf 109s with wooden tail components got thicker oil cooler armor to help keep them in balance.

We can sit at our computers/smartphones and talk about adding this or subtracting that but it was often a lot harder in real life if you want the plane to fly safely.

 

[michael rauls]

I also like finding out why things were done the way there were done.
Fighter aircraft, especially in the late 1930s were pretty tight aircraft in the design sense. There is not a lot of extra weight to fool around with even if there was extra volume in the fuselage. You have to have the center of gravity right. To get good speed and climb you have to keep the payload small.

A really good designer ties to anticipate future needs/growth rather than make a plane too tight but their crystal balls only work so well.
Somebody was smart enough on the Spitfire to put ballast weights in or on the engine mounts of the planes with the two blade wooden propellers so when they were changed to to the variable pitch props the weights could be removed and the plane's CG stayed pretty much the same,. One reason for NOT sticking fuel tank/s behind the seat on the early planes.
By the time you get to the MK IX with the two stage Merlin the Spitfire was carrying five 17.5lb weights in the tail to help balance the heavier engine and prop, this is addition to the bigger radiators/intercoolers being mounted just behind the CG.
Of course this means the MK IX was carrying 87.5 lb of pig iron that did nothing for strength or endurance or firepower or.............

Other planes did some similar things. Bf 109s with wooden tail components got thicker oil cooler armor to help keep them in balance.

We can sit at our computers/smartphones and talk about adding this or subtracting that but it was often a lot harder in real life if you want the plane to fly safely.

All truly fascinating info.
With reference to your last paragraph, I know many things are easier said than done and didn't mean this thread so much to be a criticism of designers for lack of foresight but more of a honest discussion of why things were the way they were.

 

[pbehn]

No not nescesarily. Just a curiosity hence the question. I guess the answer in the case of the p47 is more that the need for more range sprang up later and wasn't know at the time of development as opposed to the bf109 and spitfire which were a combination of this and space, wieght limitations, and possibly cog/stability issues with a larger tank if I understood everyones responses corectly.
That's what's interesting, at least to me, the why of why were things designed the way they were. That is why I started this thread. To satisfy the curiosity of those of us who don't know or think we may know but aren't sure and provoke interesting conversation and debate among those of you more knowledgeable.
It's also just a coincidence my two original and this pick involve range. Could be any feature, good or bad and I would truly love to here some others ideas or questions of why things were thhe way they were. That's one of thee things that make this all interesting. At least in my opinion.

There was an astonishing number of people who held beliefs that defied all the evidence before them. Someone said "The more enemy fighters are sent up the more we will shoot down" or similar and he was talking about the Wellington. Despite the Germans and British switching to night time bombing even in 1942 to early 43 the suggestion that the B17 couldn't get through was considered heresy to some. Escorting US bombers was not considered to be possible or actually needed until it was demonstrated to be.

 

[pbehn]

With retracting undercarriage you need somewhere for the wheels to retract into and a hydraulic or pneumatic system to power the system. The first Spitfires used a manually pumped system. system

 

[Shortround6]

All truly fascinating info.
With reference to your last paragraph, I know many things are easier said than done and didn't mean this thread so much to be a criticism of designers for lack of foresight but more of a honest discussion of why things were the way they were.

It is a very complicated subject. Sometimes politics and military considerations play into things as well as just the technical designs.
Picking on the RAF again (simply because I am lazy and have the figures at hand) they went from 12 fighter squadrons at home (British Isles) in 1925 down to 10 in 1930 and up to 14 in 1935 and then to about 54 in Jan 1940 (British Isles and France).
This vast expansion needed some sort of planes and waiting for the latest and greatest might very well mean no new planes (or very few) had fighting broke out in 1938 or very early 1939.
Again sticking with the British the Merlin I,II, III, X was available but the only other engines that were available in quantity were the Bristol Mercury and Pegasus.
The Perseus was by the handful and the Hercules was still experimental (ditto for Taurus) as were the Vulture and Sabre. less said about the A-S Tiger the better.
Without buying engines from abroad (unthinkable until about 1938) the designers, even without air ministry interference were in something of a bind. There were a lot of designs in 1937-38-39 for the "new" engines but most were placed on hold or canceled as the new engines proved a lot harder to sort out than thought.
Not to pick on the British, the Wright R-3350 was placed on hold about this time and essentially started over again with a fresh sheet of paper before it made it into the B-29 and even then things were not as desired. The continental XIV-1430 has already been mentioned.

We also have to be careful when reading some of the old requirements not to look at them with modern eyes. Like the specification for the fixed landing gear Supermarine 224. It called for a day and NIGHT fighter. This was Westlands entry into the same competition.

They really took the part about good view from the cockpit to heart and foreshadowing the P-39 got the exhaust well out of the pilots view for night fighting.
Off course with top speed of about 185mph it's chances of catching any sort of monoplane bomber were about nil.
Night fighting at the time had nothing to do with radar or any other sensor except the MK I eyeball. It had to do with being able to take-off, fly around for a while and land on the ground without crashing into anything.

 

[michael rauls]

It is a very complicated subject. Sometimes politics and military considerations play into things as well as just the technical designs.
Picking on the RAF again (simply because I am lazy and have the figures at hand) they went from 12 fighter squadrons at home (British Isles) in 1925 down to 10 in 1930 and up to 14 in 1935 and then to about 54 in Jan 1940 (British Isles and France).
This vast expansion needed some sort of planes and waiting for the latest and greatest might very well mean no new planes (or very few) had fighting broke out in 1938 or very early 1939.
Again sticking with the British the Merlin I,II, III, X was available but the only other engines that were available in quantity were the Bristol Mercury and Pegasus.
The Perseus was by the handful and the Hercules was still experimental (ditto for Taurus) as were the Vulture and Sabre. less said about the A-S Tiger the better.
Without buying engines from abroad (unthinkable until about 1938) the designers, even without air ministry interference were in something of a bind. There were a lot of designs in 1937-38-39 for the "new" engines but most were placed on hold or canceled as the new engines proved a lot harder to sort out than thought.
Not to pick on the British, the Wright R-3350 was placed on hold about this time and essentially started over again with a fresh sheet of paper before it made it into the B-29 and even then things were not as desired. The continental XIV-1430 has already been mentioned.

We also have to be careful when reading some of the old requirements not to look at them with modern eyes. Like the specification for the fixed landing gear Supermarine 224. It called for a day and NIGHT fighter. This was Westlands entry into the same competition.
View attachment 502786

They really took the part about good view from the cockpit to heart and foreshadowing the P-39 got the exhaust well out of the pilots view for night fighting.
Off course with top speed of about 185mph it's chances of catching any sort of monoplane bomber were about nil.
Night fighting at the time had nothing to do with radar or any other sensor except the MK I eyeball. It had to do with being able to take-off, fly around for a while and land on the ground without crashing into anything.

Yes it does seem to be a complicated subject. One of the reasons it's so fascinating. At least to me.
One of the general themes that seems to be emerging here, at least as it pertains to design features that may look questionable with the benefit of hindsight years later, is the constant oposing dynamics of wanting the best performance posible but needing something at least utilitarian right now/soon and in needed quantity.
As a Soviet general once said( can't remember the name right now just the quote)" quantity has a quality all its own"

 

[pbehn]

Yes it does seem to be a complicated subject. One of the reasons it's so fascinating. At least to me.
One of the general themes that seems to be emerging here, at least as it pertains to design features that may look questionable with the benefit of hindsight years later, is the constant oposing dynamics of wanting the best performance posible but needing something at least utilitarian right now/soon and in needed quantity.
As a Soviet general once said( can't remember the name right now just the quote)" quantity has a quality all its own"

The answer to most things is "it's complicated"...….. I found out reading stuff here. In general the more power you have the more you can do. Planes like the P-47 and Typhoon had the power and weight of what were considered medium bombers just a few years before like the Do-17. The Bf 109 was so small it was restricting to tall and broad pilots while P-47 pilots joked that they could take evasive action by running around the cockpit.

 

[fastmongrel]

contained more money for hay for horses than fuel for vehicles, tanks, etc.

Which is very odd seeing as the British Army had sold all it's draught horses in 1937 and most of it's Cavalry horses apart from ceremonial mounts went in 1938. The main buyer of ex Army horse's was a little known Army called the German Army.

The Indian Army still had draught and Cavalry horses in 1939.

 

[pbehn]

The common use of Barbed wire thought Europe meant that horses were of little use.

 

[KiwiBiggles]

Which is very odd seeing as the British Army had sold all it's draught horses in 1937 and most of it's Cavalry horses apart from ceremonial mounts went in 1938. The main buyer of ex Army horse's was a little known Army called the German Army.

The Indian Army still had draught and Cavalry horses in 1939.

Some people just have a real problem thinking of the UK as an industrial powerhouse, with the most completely-mechanized army in the world, and the world's biggest aircraft industry. There is a lingering perception of Britain as a bucolic idyll, populated by Colonel Blimp types and muddling by on machines built of canvas and straw.

I note that the only reference for his assertion is "I think I read in a book once".

 

[pbehn]

Some people just have a real problem thinking of the UK as an industrial powerhouse, with the most completely-mechanized army in the world, and the world's biggest aircraft industry. There is a lingering perception of Britain as a bucolic idyll, populated by Colonel Blimp types and muddling by on machines built of canvas and straw.

I note that the only reference for his assertion is "I think I read in a book once".

There were 113,000 universal carriers produced, how many have been seen in a WW2 movie? 26,00 Lloyd carriers too. There were 3 time as many Jeeps produced but 100 times more appeared in movies.

 

[Shortround6]

The common use of Barbed wire thought Europe meant that horses were of little use.

Horses may have been of little use in a cross country cavalry charge but EVERY European power except England relied on horses for the movement of goods on public roads and their armies relied on them for the movement of guns and supplies whenever and wherever the railroads could not be relied on or were overloaded.