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Stretching WW2 Designs



 
 
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  #1  
Old August 22nd 04, 05:24 PM
Presidente Alcazar
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On Sun, 22 Aug 2004 09:25:27 -0400, "Lawrence Dillard"
wrote:

Recall that the inline Allison-powered P-40, developed from a radial-powered
predecessor, benefitted from such an aft-fuselage stretch, improving its
fineness ratio, allowing for drag-reduction at the tailfin-rudder interface,
and even allowing for fitment of a low-pressure variant of the RR Merlin.
Had the stretched P-40 been given the Merlin 20 series engine, it could have
become a serious high-altitude competitor.


The P-40F and L had the Merlin 20, and the L the stretched fuselage.
I suspect you mean the Merlin 60 series, but as the first Packard
Merlin 60-series scale production didn't begin until the second half
of 1943, I can't see why the better Mustang airframe would have been
passed over in favour of what everybody was calling an obselete
airframe by 1942. The Merlin 20-engined P40's were out-performed by
the Merlin 45-engined Spitfire V as interceptors to start with, so it
made no sense to miss out on Spitfire IX/VIII production to use the
engines concerned to produce Merlin 60-engined P-40s.

Ballasting was not usually a good solution. In the Spitfire, for example,
ballasting was not very efficient when used in conjunction with the wider
and heavier Griffons, rendering tricky handling and at least one
test-establishment evaluation calling for cessation of production of Griffon
variants for that reason.


That was an early variant of the F.21, where the evaluation
establishment went beyond their remit, and where in any case the
problem was fixed. Meanwhile, two Griffon-engined versions had
previously gone into service, the first (the Mk XII) about eighteen
months beforehand, and the second (the Mk XIV) with great success,
being called the best single-engined fighter tested by the AFDU to
that point.

Gavin Bailey

--

Apply three phase AC 415V direct to MB. This work real good. How you know, you
ask? Simple, chip get real HOT. System not work, but no can tell from this.
Exactly same as before. Do it now. - Bart Kwan En
  #2  
Old August 24th 04, 01:47 PM
Peter Stickney
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In article ,
Presidente Alcazar writes:
On Sun, 22 Aug 2004 09:25:27 -0400, "Lawrence Dillard"
wrote:

Recall that the inline Allison-powered P-40, developed from a radial-powered
predecessor, benefitted from such an aft-fuselage stretch, improving its
fineness ratio, allowing for drag-reduction at the tailfin-rudder interface,
and even allowing for fitment of a low-pressure variant of the RR Merlin.
Had the stretched P-40 been given the Merlin 20 series engine, it could have
become a serious high-altitude competitor.


The P-40F and L had the Merlin 20, and the L the stretched fuselage.
I suspect you mean the Merlin 60 series, but as the first Packard
Merlin 60-series scale production didn't begin until the second half
of 1943, I can't see why the better Mustang airframe would have been
passed over in favour of what everybody was calling an obselete
airframe by 1942. The Merlin 20-engined P40's were out-performed by
the Merlin 45-engined Spitfire V as interceptors to start with, so it
made no sense to miss out on Spitfire IX/VIII production to use the
engines concerned to produce Merlin 60-engined P-40s.


The P-40Fs and P-40Ls were also outperformed by various
Allison-powered P-40 models as well. The single stage Merlins, while
very, very good engines, weren't the leap in performance over its
rivals that the 2-stage (60 series and up) engines were.


Ballasting was not usually a good solution. In the Spitfire, for example,
ballasting was not very efficient when used in conjunction with the wider
and heavier Griffons, rendering tricky handling and at least one
test-establishment evaluation calling for cessation of production of Griffon
variants for that reason.


That was an early variant of the F.21, where the evaluation
establishment went beyond their remit, and where in any case the
problem was fixed. Meanwhile, two Griffon-engined versions had
previously gone into service, the first (the Mk XII) about eighteen
months beforehand, and the second (the Mk XIV) with great success,
being called the best single-engined fighter tested by the AFDU to
that point.


A couple of points here - the Griffon's frontal area wasn't that much
more than the Spitfires, and it was notably wider only at the top of
the cylinder blocks and heads. It wasn't that much longer overall,
either, due to clever relocation of the engine accessories.
While the Griffon Spits may have lost some of the Spitfire's perfect
handling, it didn't lose much. and the Royal Navy was flying them
from carrier decks into the 1950s. I couldn't have been that bad.
(They chose to dump the Corsair and keep the Seafires, after all.)

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster
  #3  
Old August 31st 04, 09:30 AM
Presidente Alcazar
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On Tue, 24 Aug 2004 08:47:13 -0400, (Peter
Stickney) wrote:

The P-40Fs and P-40Ls were also outperformed by various
Allison-powered P-40 models as well.


Mmm, depends on height and chronology, though. Certainly in mid-1942
the Merlin engined variants were preferred for both the USAAF and RAF
on performance grounds over the contemporary Allison models. I think
that's easy to overstate, though. Production availability was the
main determinant. By 1943 there were only Allison variants being
produced, which is when (in the second half of the year) Packard
started to deliver Merlin 60-series engines. The Spitfire, Mosquito
and Mustang were all airframes with a better claim for the increased
performance of the Merlin 60 series than the P-40. Meanwhile, the
1943-vintage P-40s with Allison engines were clearly better performers
at lower altitudes, which is where most of their operational
employment took place, so there was no sense in using Merlin 20-series
production for them in 1943.

The single stage Merlins, while
very, very good engines, weren't the leap in performance over its
rivals that the 2-stage (60 series and up) engines were.


Sure, but I know the RAF specifically preferred the Merlin-engined
variants, and the allocations of USAAF-controlled P-40s indicates that
when Merlin-engined variants were coming off the production lines, the
USAAF wanted them in preference to Allison-engined variants being
produced at the same time, which they directed to lend-lease supply
for Britain, Australia, New Zealand and Russia. I appreciate the
performance differential involved was marginal, but it does seem to
have influenced procurement policy.

Having said that, those decisions were the ones made in early to
mid-1942, and by forces which relied on P-39s and Hurricanes for the
mainstay of their operational fighter strength. When exposed to the
FW 190, by early 1943, senior commanders in North Africa were
demanding better performance fighters than the P-40L and the Spitfire
V which themselves had been the favoured options less than a year
earlier.

A couple of points here - the Griffon's frontal area wasn't that much
more than the Spitfires, and it was notably wider only at the top of
the cylinder blocks and heads. It wasn't that much longer overall,
either, due to clever relocation of the engine accessories.
While the Griffon Spits may have lost some of the Spitfire's perfect
handling, it didn't lose much. and the Royal Navy was flying them
from carrier decks into the 1950s. I couldn't have been that bad.
(They chose to dump the Corsair and keep the Seafires, after all.)


Well, some of that comes down to the exigencies of supply politics,
e.g. the end of lend-lease and the termination of any substantive
dollar-procurement programmes due to lack of dollars. I think the
Seafire was an underestimated carrier fighter, but if I'd had the
option in late 1945 I would have kept the FAA on (certainly) Hellcats
and (possibly) Corsairs.

Gavin Bailey

--

But, first, want speed. Bart not greedy as all know. 250MHz enough.
I attempt use SGI chip in MB. But chip not fit, then I bend pins. Shove in MB hard.
Now apply hammer. Yeah, sit down, ****er! Power on, go BEEEEEP! - Bart Kwan En
  #5  
Old August 31st 04, 03:30 PM
Presidente Alcazar
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On Tue, 31 Aug 2004 10:00:11 +0100, "Keith Willshaw"
wrote:

Trouble is the double decked hangar ships (Implacable and Indefatigable)
didnt have the hangar clearance to operate Corsairs and there were
problems getting enough Hellcats.


There certainly were after September 1945.

In fact the performance of the
Seafires with the BPF in the fleet defence abd CAP role was quite good with
landing accidents being much reduced as they gained experience.


The above was my basic point, albeit in a post-Hiroshima, end-of-WW2
setting.

Gavin Bailey

--

But, first, want speed. Bart not greedy as all know. 250MHz enough.
I attempt use SGI chip in MB. But chip not fit, then I bend pins. Shove in MB hard.
Now apply hammer. Yeah, sit down, ****er! Power on, go BEEEEEP! - Bart Kwan En
 




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