P-47 thunderbolt Throttle Quadrant Placard

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T Bolt

Colonel
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Mar 24, 2010
Chicago, Illinois
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Does anyone know what is written on the placard mounted on the throttle quadrant mounting bracket on the P-47 Thunderbolt? I need to reproduce it and I have several pictures shown below but they show only the right ½ of the placard or not clear enough to see.
 
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These might help. Piecing the pics together, it looks like"WARNING. This airplane has a supercharged engine. Take-off and operation must be in accordance with 'Operation Instructions' in Form 1"
 

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D**m that was fast service Andy 13 minutes!!! THIS FORUM IS AWESOME!!!
Thanks a million! That was exactly what I needed now have the whole text!
 
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All of 'em as far is I know. Turbo-supercharger to be exact.

Yes that's right the Thunderbolt was built around the Turbo-supercharger starting with the P-43 Lancer which was a Turbo-supercharged version of the P-35 and from which the P-47 was developed. You can see the family resemblance below:

P-35
P-43 Lancer
P-47B Thunderbolt
 
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In a turbo supercharger, the supercharger is driven by a turbine which is powered by exhaust gasses from the engine. With straight supercharger such as in the Mustang or Spitfire the supercharger is geared directly to the engine.

In the Thunderbolt the turbo supercharger was located in the lower rear fuselage and ducting lead the exhaust gasses back to the turbine and spun it, which spun the supercharger which compressed air and sent it back forward to the engine carburetor. The air return ducts can be seen in the side walls of the cockpit in some pictures. The speed of the turbo was controlled by exhaust waist gate valves located on both sides of the fuselage just behind the cowl flaps in front of the wing roots. When the valves were open the exhaust would be directed out at that point and the tubro would not operate. As the valve would open the exhaust would be directed back to the tubro. The farther open the valve the faster the tubro would spin. there was an indicator light on the control panel that would blink when the tubro was operating at optimum speed. the light would go steady when the tubro would reach max speed and the pilot would have to back it off until it was blinking again. It seemed to be a case of constant adjustment as the plane climbed to altitude.
 
It was once explained to me that the name 'Turbocharger' came from the combination of terms describing the workings of a supercharger driven, or assisted, by exhaust gasses. The words 'themal' and 'turbulence' being used, refering to to the hot turbulent air ducted or drawn from the exhaust, hence 'Turbo', and then added to the Supercharger word, making 'Turbo-charger', commonly refered to as 'Turbocharger'.
 
In layman's A&P terms - if it's engine driven, its a supercharger - If it's driven by exhaust its a turbocharger.
 
In layman's A&P terms - if it's engine driven, its a supercharger - If it's driven by exhaust its a turbocharger.

Yes thats it in a nutshell.

Supercharger = The device that compresses the air being fed into the carburetor, either engine or exhaust driven, but when referred to as just "Supercharger" is usually engine driven.

Turbine = The device attached to the supercharger that catches the exhaust gasses and powers the supercharger.

Turbo Supercharger =The turbine and the supercharger together are called the "Turbocharger", "Turbo Supercharger", or just "Turbo" for short. Andy posted an excellent picture of the Turbo Supercharger above.
 
The thing to watch in a turbocharged aircraft was not to overboost during take off and I think that was the purpose of the placard. I've flown Turbo Cessna 210s and it took some getting used to not to slam the throttle full forward rapidly during take off.
 
Supercharger = The device that compresses the air being fed into the carburetor, either engine or exhaust driven, but when referred to as just "Supercharger" is usually engine driven.

Turbo Supercharger = The turbine and the supercharger together are called the "Turbocharger", "Turbo Supercharger", or just "Turbo" for short
I'm happy with how both techniques work
I was wondering at what point in history that silly term crept into the vocabulary when 'turbocharger' said it just fine
 
I have a DVD of the P-47 training film from 1943 and in it the instructor explains the operation of the "Turbo Supercharger", many times when he is referring to it he calls it the "Turbo" I'm sure that some time later the term "Turbocharger" came in as it was somewhere in between the two other terms. My father who flew on B-24's from 1943 to 1945 used the term "Turbocharger"
 
I knew someone would catch that! :oops: I had to edit that line out or the placard would not have fit on the available space I had to mount it in the throttle quadrant bracket. I think my bracket is not as deep as it should be. It was one of the hardest parts to dimension from photos and then to make so I'm just going to have to live with it.
 

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