AHC: Wank the Spitfire

Spitwank.png

1939 Spitwank.
 
Size comparison between the important 'flying guns' of ww2: picture. Please note that Oerlikon FF is the size of the Browning HMG, and half the length of the Hispano 404, that was about as long as the 30mm MK 103. The Japanese Type 99-2 was the offspring of the Oerlikon FFL, that was between the FF and FFS/Hispano 404 power- & size-wise.
The later Hispano V was shorter, lighter, and fired at greater rate (~800 rpm vs. ~600), at a price of a slight decrease in muzzle velocity.

About the more users part: the Canadian Spitfire might've used the UK-made parts initially, later switch to the Packar Merlins like it was done with Hurricanes produced there. Perhaps install V-1710 until the Packard's prodution ramps up - should've been faster than P-40 of the era, at least as fast as P-39 with same generation of engines, while comfortably out-climbing those. Later install the 2-stage V-1710 for 400++ mph, perhaps alos as a retro-fit to the USAF Spitfires Mk.V.
The radial-engined Spitfire - initially as an insurance if RR lines are bombed, later used by FAA (with Hecules) and as a fighter-bomber, perhaps also by Australia (with Twin Wasp).


Tempest's wings and, obviously, undecarriage, Mustang-inspired radiator & ram air intake set-up, Griffon with counter-rotating props, bubble canopy, all connected by Spitfire fuselage - basically the best the Allies can throw in. Excellent, and too bad such a Spitfire didn't existed in OTL.
 
Size comparison between the important 'flying guns' of ww2: picture. Please note that Oerlikon FF is the size of the Browning HMG, and half the length of the Hispano 404, that was about as long as the 30mm MK 103. The Japanese Type 99-2 was the offspring of the Oerlikon FFL, that was between the FF and FFS/Hispano 404 power- & size-wise.
The later Hispano V was shorter, lighter, and fired at greater rate (~800 rpm vs. ~600), at a price of a slight decrease in muzzle velocity.

About the more users part: the Canadian Spitfire might've used the UK-made parts initially, later switch to the Packar Merlins like it was done with Hurricanes produced there. Perhaps install V-1710 until the Packard's prodution ramps up - should've been faster than P-40 of the era, at least as fast as P-39 with same generation of engines, while comfortably out-climbing those. Later install the 2-stage V-1710 for 400++ mph, perhaps alos as a retro-fit to the USAF Spitfires Mk.V.
The radial-engined Spitfire - initially as an insurance if RR lines are bombed, later used by FAA (with Hecules) and as a fighter-bomber, perhaps also by Australia (with Twin Wasp).



Tempest's wings and, obviously, undecarriage, Mustang-inspired radiator & ram air intake set-up, Griffon with counter-rotating props, bubble canopy, all connected by Spitfire fuselage - basically the best the Allies can throw in. Excellent, and too bad such a Spitfire didn't existed in OTL.

Not having having a go 'but'.....on this forum I often see something like this "lets build this in case that got bombed etc" - the thing is factories did get bombed in WW2 particularly in Germany and in many cases were often up and running within weeks if not days - so in this case I would suggest that all efforts are thrown at the core design be continually improved with the Merlin then later the Griffon engines etc.

As for the HS 404 it was firing a round that had a much higher MV than the other cannon and while the MK 103 was the same length as the HS 404 it was a lot 'fatter' and nearly 4 x the weight (43 kgs vs 141 kgs) and the 103 was mounted 1 per wing in Gondola pods. The lighter less powerful MK 108 is probably a better comparison.
 
Not having having a go 'but'.....on this forum I often see something like this "lets build this in case that got bombed etc" - the thing is factories did get bombed in WW2 particularly in Germany and in many cases were often up and running within weeks if not days - so in this case I would suggest that all efforts are thrown at the core design be continually improved with the Merlin then later the Griffon engines etc.

There is probably no doubt that Merlin and later Griffon seemed like tailor-made for the Spitfire; cancelling out two or 3 other RR engines from the late 1930s/early 1940s makes a situation even better. The suggestions from the post above are not unlike what was proposed eg. for the Hurricane, where we can seed the Dagger, Griffon or even the Centaurus proposed.

As for the HS 404 it was firing a round that had a much higher MV than the other cannon and while the MK 103 was the same length as the HS 404 it was a lot 'fatter' and nearly 4 x the weight (43 kgs vs 141 kgs) and the 103 was mounted 1 per wing in Gondola pods. The lighter less powerful MK 108 is probably a better comparison.

Looks like the Hisso II was at 50 kg (belt feed device upping the weight a bit vs. regular HS 404?), the Hisso V was at 42 kg. Granted, the MK 101 or 103 will be hardly installed within the confines of a wing of a S/E fighter, even if we try with the Corsair's thick wings.
The reason I've mentioned the short length of the Oerlikon FF was that it would've probably fit fully within the Spitfire's wings, thus stealing less speed than the Hispano II/MS 404 with it's protruding barrel. The lower weight will allow 4 small FF cannons for the same weight allowance as for two Hisso II + 4 .303s, making the target is under twice the number of shells if the pilot has the correct firing solution.
Indeed, the big Hispano was with excellent muzzle weight, thus will have easier time to obtain hits on a more demanding (small, aware, maneuvering, distant, or a combination of that) target. All in all - there is no such thing as a free lunch.
 
... cancelling out two or 3 other RR engines from the late 1930s/early 1940s makes a situation even better.
The trick of course being which engines to cancel. IIRC developments made on earlier engines, including ones that didn't go into production, fed into the development of later ones like the Merlin or Griffon. Just Leo would be the person to ask about that.
 
There is probably no doubt that Merlin and later Griffon seemed like tailor-made for the Spitfire; cancelling out two or 3 other RR engines from the late 1930s/early 1940s makes a situation even better. The suggestions from the post above are not unlike what was proposed eg. for the Hurricane, where we can seed the Dagger, Griffon or even the Centaurus proposed.



Looks like the Hisso II was at 50 kg (belt feed device upping the weight a bit vs. regular HS 404?), the Hisso V was at 42 kg. Granted, the MK 101 or 103 will be hardly installed within the confines of a wing of a S/E fighter, even if we try with the Corsair's thick wings.
The reason I've mentioned the short length of the Oerlikon FF was that it would've probably fit fully within the Spitfire's wings, thus stealing less speed than the Hispano II/MS 404 with it's protruding barrel. The lower weight will allow 4 small FF cannons for the same weight allowance as for two Hisso II + 4 .303s, making the target is under twice the number of shells if the pilot has the correct firing solution.
Indeed, the big Hispano was with excellent muzzle weight, thus will have easier time to obtain hits on a more demanding (small, aware, maneuvering, distant, or a combination of that) target. All in all - there is no such thing as a free lunch.

As we are improving the Spitfire then surely the obvious answer would be to buy the rights as well as plans etc for the shorter barrelled HS 404.

The version the British originally had was the one that was designed (as I understand it) to be fired through the Prop Hub of an aircraft necessitating a long barrel - this is obviously not required in a wing mounting.

It staggers me where the Brits saved a pittance requiring them to expend so much time lives and effort later on

So fitting a pair of shorter 'wing' HS 404s on each side should and did resolve this issue - just a lot earlier
 
IIRC the Air Ministry wanted to order 389 Hawker Hotspurs from Avro in the summer of 1936. All 389 aircraft were to be delivered by 31st March 1939. Then there would be 126 aircraft in 9 squadrons of 14 with the rest in reserve. These squadrons were intended to be the fighter element of the Air Component of the British Expeditionary Force.

Unfortunately Avro's factories didn't have the capacity to build them plus the Ansons and 1,000 Bristol Blenheims that they produced IOTL.

Therefore the Air Ministry had to order the other contender to Specification F.9/35 the Defiant. However, the first 87 production Defiants were not ordered until 28th April 1937 and the first production aircraft did not fly until 30t July 1939. It seems that the second production contract (for 389 aircraft) was placed in January 1939, followed by 202 in February 1938 and 161 three months later. [Source Aircraft of the Few, buy Michael Bowyer, I think February 1938 must be a typo for February 1939.]

I want Boulton Paul to build Spitfires in place of the Defiant. Therefore I think it is reasonable for the Air Ministry to order 389 Spitfires from that firm in the summer of 1936 instead of the planned order of Hotspurs from Avro. With a head start of 6-9 months I think that the first Boulton Paul built Spitfire would fly at the end of January 1939 and possibly as early as the end of October 1938.

According to a Cabinet Paper dated October 1937 the estimated costs of the Spitfire and Defiant were £8,000 and £10,500 which if correct means building more Spitfires instead of the Defiant would save some money as well as lives.
 
What? - I'm sorry I...I had no idea. I feel so foolish. Consider my original statement withdrawn in that case.
At October 1937 prices £2,500 is saved for every Spitfire built instead of a Defiant. Even at 2017 prices that buys a lot of tea and buns. At October 1937 prices £2,500 might have bought a few Hispano currant buns.
 
According to a Cabinet Paper dated October 1937 the estimated costs of the Spitfire and Defiant were £8,000 and £10,500 which if correct means building more Spitfires instead of the Defiant would save some money as well as lives.

Estimated costs may vary from correctness. I do recall reading that a Hurricane cost 10500 pounds, which seems counter-intuitive.

There were some figures in the enginehistory article on ramp-head Merlins suggesting that it cost 6000 pounds for a prototype engine and 3000 pounds for a production engine and Rolls Royce blew 582,000 pounds on an engine dead-end to 1938 which meant dry scones for quite some time. This is a Spitfire wank, not a Merlin wank, but the engine development is a considerable aspect of Spitfire wankitude.
 
Estimated costs may vary from correctness. I do recall reading that a Hurricane cost 10,500 Pounds, which seems counter-intuitive.

There were some figures in the enginehistory article on ramp-head Merlins suggesting that it cost 6,000 Pounds for a prototype engine and 3,000 Pounds for a production engine and Rolls Royce blew 582,000 Pounds on an engine dead-end to 1938 which meant dry scones for quite some time. This is a Spitfire wank, not a Merlin wank, but the engine development is a considerable aspect of Spitfire wankitude.
You once wrote that I wrote like a non-engineer. That's because I'm a bookkeeper. One of the basic principles of accounting is consistency...
The consistency principle states that, once you adopt an accounting principle or method, continue to follow it consistently in future accounting periods. Only change an accounting principle or method if the new version in some way improves reported financial results.
I suspect that the differences in cost are due to not applying the consistency principle. The costs from the Cabinet Paper are the estimated costs complete. That is...
The figures of cost (which, for the latter types, are estimated only) shown includes airframe, engine(s), aircraft equipment (instruments, &c.) and armament, other than bombs and ammunition.
The only other type powered by a single Merlin in the list was the Fairey Battle and the cost of that was £11,750, which as that type was actually in production in October 1937 was likely to have been the actual unit cost not the estimated unit cost.
 
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The trick of course being which engines to cancel. IIRC developments made on earlier engines, including ones that didn't go into production, fed into the development of later ones like the Merlin or Griffon. Just Leo would be the person to ask about that.

I'm not sure that Exe contributed anything to the Merlin, nor Griffon, being an air-cooled X-24 engine, with sleeve valves and master+articulated rod assembly vs. the classic fork and blade rod assembly. The Peregrine was a later design than the Merlin, even if we discount the ramp-head early versions. And even as such it was not able to beat RPM of the Merlin (desite being of smaller stroke), let alon the boost the Merlin was capable for.
RR can try to militarize the R engine in order to have the high power V12 engines for the needs of the RAF.

As we are improving the Spitfire then surely the obvious answer would be to buy the rights as well as plans etc for the shorter barrelled HS 404.
The version the British originally had was the one that was designed (as I understand it) to be fired through the Prop Hub of an aircraft necessitating a long barrel - this is obviously not required in a wing mounting.
It staggers me where the Brits saved a pittance requiring them to expend so much time lives and effort later on
So fitting a pair of shorter 'wing' HS 404s on each side should and did resolve this issue - just a lot earlier

The picture of the shorter cannons was depicting the Hispano V, the British development of the belt-fed variant of the Hispano II, that was a sight modification of the HS 404. Or, in other words, there was no short barrel Hispano in service before 1944.
The reason I've proposed the Oerlikon cannons was not that they were any better than the Hispano, but that their timing was far more suitable for the needs of the RAF (that was also noted by another poster on this thread). RAF was even testing the belt-fed Oerlikon S cannon (muzzle energy comparable with HS 404) in the late 1920s/early 1930s, but nothing came out of it.
There was also the Oerlikon FFL (or just L), power-wise between the light FFF and powerful FFS, that weighted 34 kg and fired at 490-500 rpm, 750 m/s by 1930s. Japanese used the 100 rd drum, before introducing the belt feeding. Article by Tony Williams: link; article at lonesntry.com: link.
 
I've a kit somewhere of the Hotspur and it's a BIG aircraft that's nearly twice the size of a Hurricane. Not building them was probably a blessing in disguise.
 
I've a kit somewhere of the Hotspur and it's a BIG aircraft that's nearly twice the size of a Hurricane. Not building them was probably a blessing in disguise.

That's not true. Try taking a closer look. There are a couple different wingspans given in sources, neither near twice as big, and the length is just inches.
 
Estimated costs may vary from correctness. I do recall reading that a Hurricane cost 10500 pounds, which seems counter-intuitive.

There were some figures in the enginehistory article on ramp-head Merlins suggesting that it cost 6000 pounds for a prototype engine and 3000 pounds for a production engine and Rolls Royce blew 582,000 pounds on an engine dead-end to 1938 which meant dry scones for quite some time. This is a Spitfire wank, not a Merlin wank, but the engine development is a considerable aspect of Spitfire wankitude.

I suspect that the higher figures quoted could be cost/numbers, so its the plane, engine, propeller (surprisingly expensive), guns, other supplied equipment, and possibly spares. Its terribly difficult to say, because its rare to see a full breakdown. Maybe because everyone 'knew' what the cost referred to, so didn't bother to record it?

Either that or its the precursor of the creative cost accounting we know and love(?) in todays defence industry...
 
I suspect that the higher figures quoted could be cost/numbers, so its the plane, engine, propeller (surprisingly expensive), guns, other supplied equipment, and possibly spares. Its terribly difficult to say, because its rare to see a full breakdown. Maybe because everyone 'knew' what the cost referred to, so didn't bother to record it?

Either that or its the precursor of the creative cost accounting we know and love(?) in todays defence industry...

I don't profess to know beans about bean-counting, and my knowledge of accountants is limited to Arthur Pewty, who wanted to be a lumberjack. However, the same chaps who were estimating the cost of a Spitfire in 1937 were probably also estimating it based on production at Supermarine, where it was at a standstill, waiting for cost estimates on revision to the wing leading edge of thicker gauge due to flutter, and expected from production at Castle Bromwich, one of the greatest money pits of the era. If you can't estimate production, how can you estimate cost?
 
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