Hello All :
To Mr. TomFromCornwall :
Thanks for offering an opinion and correcting the correction re aircraft held by Eastern
Seaboard Command. I don't want to head down a rabbit hole here, but were long range ASW aircraft
converted from bomber aircraft transferred to the USN or retained and used by US Army Air Corps units
in an ASW role like the British RAF Coastal Command (BTW apologies to my Americans colleagues if I
keep saying USAAC when it should be USAAF - I'll go away and look that up!).
The first group of B-24s supplies to Britain were, like the first group of B-17s, the P-39s, and the P-38s,
delivered to Britain WITHOUT TURBOCHARGERS .
The reason that the prototype XB-24 was slower than it's contract airspeed, as Mr. Anderson has noted,
was because it HAD NO TURBOCHARGERS !
When the Turbochargers were installed on the second prototype,
it made it's designed speed, along with it's designed ceiling, designed range, and designed payload capability.
This was also true for the Boeing B-17. The prototype, the Boeing Model 299, had no turbochargers, and as
a result, was powered by four Pratt-Whitney Hornets that put out only 762 hp each, far less than later,
For this reason, the USAAF ( THE AIR FORCE !
) ordered the B-24 into production. However, there
was a fly in the ointment. To understand this, we have to go back to the 1920s-1930s. The 'salad days'
of the U.S. Military. Poverty Row. No money. During this period, the most famous aircraft in the USAAC
were the Boeing P-26 Peashooter, the Martin B-10, and the Curtiss A-8 / A-12 Shrike ground attack aircraft.
The total numbers of these aircraft built for the USAAC were 139, 166, and 61, respectively.
Now, starting the in middle 1930s, the USAAC began putting out contracts for an entirely new suite of
aircraft, all to be powered either by the Allison V-1710 or by either a Curtiss-Wright or Pratt-Whitney
radial, and ALL to be turbocharger equipped. These included the Curtiss P-37, Lockheed P-38, Bell P-39,
Seversky P-43, the Boeing B-17, and the Consolidated B-24.
During the period, turbochargers were made almost exclusively by the General Electric Corporation. So,
at some point in late 1939 / early 1940, there was a board meeting at G.E., and the question came up,
" The Army is going to want turbochargers. What do we have to do to make sure we get this business ? "
" Well, How many of these turbocharger gadgets will they want ? If we build a huge plant, and they
only order a few, then we have to amortize the cost of building, facilities, equipment, and manpower
among only a few turbochargers. It might be better if we build the factory based on how MANY
turbochargers the USAAF is going to want. "
" Well, let's see. They are going to use them in the B-17, the B-24, the P-37, the P-38, the P-39, and
the P-43. Let's assume they order one hundred of each airplane - after all, that's a LOT of airplanes,
right ? So, that's 400 for the B-17s, 400 for the B-24s, 100 each for the P-37s, P-39s, and P-43s, and
200 for the P-38s - how many is that ? "
" Uhhhhhhhhhh .......... that's 1300. "
" Well, let's assume we have to make a few spares. Like, a total of say, 1500 turbochargers. And, if
they will want them all by the end of 1942, that means that, assuming we spend a year getting the factory
ready, we wil have two years to make 1500 Turbochargers. Hmmmmm........ 750 per year. Thats about
15 per week, or about three per work day. O.K. So, we will need six lathes, six milling machines, one
big forge, two surface grinders, six drill presses, six bench grinders, two annealing ovens, and some what-not.
No Problem. "
And that was the problem. When the time came, the USAAF ordered THOUSANDS of B-17s and B-24s and P-38s
and everything else. And that meant, there weren't enough turbos to go around. Which meant that somebody
would have to go to bed hungry. First, the USN was out of the picture. " NAVY ? NO TURBO'S FOR YOU !!!! "
Then came the P-37. Cancelled. build the P-40 instead, with no turbo.
P-39 ? No Turbo's for YOU !
P-38 ? Well, we have enough to equip the P-38s for the USAAF, but the one's ordered by Britain...." England ?
NO TURBO'S FOR YOU ! "
The same applied to the B-17s and the B-24s ordered by Britain. " NO TURBO'S FOR YOU ! " Which was why
the British B-24s were converted to coastal patrol ( low level flying ) and LB-30 transports ( No bomb or gun
turret load ) The RAF tried to use the B-17s without turbo's on a few missions, and gave it up. And, when
the first P-38s and P-39s without turbo's showed up, they got rejected. The RAF flew the P-39s for about
a month, and realized they were a lost cause. They cancelled the order, and the USAAF took them on as
P-400s and sent them to MacArthur in New Guinea. The P-38s without turbo's were rejected without even
testing them, and the USAAF branded them ' P-322 s " and used them to train P-38 pilots. Who called them
All through 1941 and 1942, G.E. was working like slaves in hell to both build enough turbochargers and
also build extra manufacturing plant to make LOTS MORE turbochargers, with the result that, by the beginning
of 1943, the shortage was pretty much over.
But, that still meant a lot of lousy P-400s being shot down in New Guinea ( the pilots said that a P-400
was a P-40 that came equipped with the Zero already on it's tail ! ) and, more importantly for our discussion,
a lot of B-24's that couldn't carry the weight of guns, bombs, and fuel to 25,000 feet over Germany. But,
they could carry a load of bombs at 5,000 feet over the Atlantic, or the Caribeean, and make life miserable
for the Kriegsmarine.
For a visual clue, if you see a B-24 with round ( circular ) engine cowlings, it is non-turbocharged. If it has
oval cowlings, ( wider than they are tall ) it is probably turbocharged. Now, the B-24s supplied to THE NAVY !
were redesignated PB4Ys, in various sub types, and were flown on both sides of the Atlantic by U.S. naval
aviators, USAAF pilots, and RAF types. Usually the markings and paint schemes can tip you off as to who is at the controls.
And now the rabbit is kicking everyone out of his hole. After all, He is Late for a Tea Party !
Paul R. Ward