Pratt & Whitney T34

This article is about an aircraft engine. For other uses, see T34.

The Pratt & Whitney T34 (company designation PT2 Turbo-Wasp^[2]) is an American axial flow^[2] turboprop engine designed and built by Pratt & Whitney. Its only major application was on the Douglas C-133 Cargomaster.

T34 Turbo-Wasp
A B-17 Flying Fortress testbed for the T-34 turboprop engine. This aircraft was later flown on airshow circuits as the Liberty Belle.[1]
Type	Turboprop
National origin	United States
Manufacturer	Pratt & Whitney
First run	ca. 1950
Major applications	Douglas C-133 Cargomaster

Design and development

In 1945, the United States Navy funded the development of a turboprop engine. The T34 was produced from 1951 to 1960, but never used in U.S. Navy aircraft production.^[3]

The YT34 engine with three wide-bladed propellers was made for two Navy Lockheed R7V-2 Constellation (C-121s) variants, for testing. Flight tests were on 1 September 1954.^[4]

In September 1950, a testbed Boeing B-17 Flying Fortress flew with a T34 turboprop mounted in the nose of the bomber. The first application for the T34 was the Boeing YC-97J Stratofreighter, which later became the Aero Spacelines Super Guppy. The next application for the engine was the Douglas C-133 Cargomaster.^[3]

Variants

The Douglas C-133 Cargomaster was the largest aircraft to use the T34.

T34-P-1

5,700 shp (4,300 kW) equivalent.

T34-P-2

Similar to -1.

T34-P-3

6,000 shp (4,500 kW) equivalent.

YT34-P-5

5,229 shp (3,899 kW) equivalent^[5]

T34-P-6

5,531 shp (4,124 kW) equivalent^[6]

T34-P-7

T34-P-7W

7,100 shp (5,300 kW) equivalent, w/water injection

T34-P-9W

7,500 shp (5,600 kW) equivalent, w/water injection

T34-P-12

YT34-P-12A

5,500 shp (4,100 kW) equivalent^[7]

PT2F-1

5,500 shp (4,100 kW) equivalent, unbuilt civilian version planned to power the Lockheed L-1249B.^[8]

PT2G-3

5,600 shp (4,200 kW) equivalent, unbuilt civilian version planned to power the Lockheed L-1449 and possibly the L-1549.^[8]

Applications

The experimental Douglas YC-124B Globemaster II powered by four Pratt & Whitney YT-34-P-6 turboprops

Lockheed R7V-2 Constellation

• Aero Spacelines Super Guppy
• Boeing YC-97J Stratofreighter (YT34-P-5)^[5]
• Douglas YC-124B Globemaster II^[9]
• Douglas C-133 Cargomaster
• Lockheed R7V-2 Constellation (YT34-P-12A)^[10]
• Lockheed YC-121F Constellation (T34-P-6)^[6]

Engines on display

• T34-P-3: National Air and Space Museum^[11] (NASM) in Washington, D.C.
• T34-P-6: Travis Air Force Base Heritage Center in Fairfield, California
• T34-P-7W: NASM^[11]
• T34-P-7WA: Pacific Coast Air Museum (PCAM) in Santa Rosa, California

Specifications (T34-P-3)

Data from Jane's All The World's Aircraft 1961–62.^[12]

General characteristics

• Type: Turboprop
• Length: 156.8 in (3,983 mm)
• Diameter: 33.75 in (857 mm)
• Dry weight: 2,590 lb (1,175 kg)

Components

• Compressor: 13-stage axial compressor
• Combustors: annular combustion chamber with eight flame tubes
• Turbine: three-stage axial-flow
• Fuel type: JP-4
• Oil system: closed circuit

Performance

• Maximum power output: 5,500 shp (4,103 kW) plus 1,252 lbf (5.57 kN) thrust, 6,000 ehp (4,476 kW) (take-off power)
• Overall pressure ratio: 6.7:1
• Power-to-weight ratio: 2.32 ehp/lb

See also

Related development

• Pratt & Whitney T57

Comparable engines

• Allison T56
• Allison T61
• Rolls-Royce Tyne

Related lists

• List of aircraft engines