B-33 Super Marauder

B-33 Super Marauder
Type	Medium bomber
Manufacturer	Martin
Status	Cancelled 1942-11-25
Primary user	U.S. Army Air Force
Number built	0
Developed from	B-26 Marauder

The Martin XB-33 Super Marauder (company Model 190) was conceived by Martin as a high-altitude derivative of the Martin B-26 Marauder, that might eventually replace it. The design was different in many ways, most notable in its twin tail (the B-26 had a single tail). It also featured pressurised crew compartments.

XB-33

Schematic blueprint drawing of the XB-33.

The first version of the design, the XB-33 was a twin-tailed medium bomber with two Wright R-3350 engines and pressurised crew compartments; its design began in 1940. It would carry around 4,000 lb (1,800 kg) of bombs. Soon after design of the XB-33 began, Martin engineers decided it would be more productive to make a drastic overhaul to the design than continue polishing it. This resulted in the XB-33A. For this reason, no XB-33s were built.

Specifications (as designed):

• Length: 71 ft 0 in (22 m)
• Wingspan: 100 ft 0 in (30 m)
• Height: 22 ft 6 in (6.86 m)
• Engines: 2× Wright R-3350 radial engines of 1,800 hp (1,300 kW) each

XB-33A

As design progressed, it became clear that a two-engine aircraft would not achieve the performance requested by the army. Instead of refining its original design, Martin engineers chose a major alteration of the design, increasing the number of engines to four, and the size of the aircraft was increased to that of the B-29 Superfortress; its bombload was to have been 12,000 lb, as much as that of the B-24 Liberator, the heaviest bomber flown in combat prior to the B-29. This new design, dubbed the XB-33A, was impressive enough that the Army Air Force ordered two prototypes.

Where the original XB-33 was to be powered by the R-3350, the redesigned XB-33A was to use less powerful Wright R-2600 engines. The main reason for this was demand for R-3350s for the B-29, one of the most highly valued projects of the Army Air Forces.

On January 17 1942, the Army Air Force placed an order for 402 B-33A Super Marauders. They were to be produced at the government-owned plant in Omaha, Nebraska operated by Martin. However, the entire B-33 project was cancelled on November 25, 1942, to allow the Martin-operated Omaha plant to concentrate on manufacturing B-29s.

Specifications (B-33A, as designed)

General characteristics

• Crew: 7
• Length: 79 ft 10 in (24.3 m)
• Wingspan: 134 ft (40.8 m)
• Height: 24 ft (7.32 m)
• Wing area: 1,646 ft² (153 m²)
• Empty weight: 85,000 lb (39,000 kg)
• Loaded weight: 95,000 lb (43,000 kg)
• Powerplant: 4× Wright R-2600-15 radial engines, 1,800 hp (1,300 kW each) each

Performance

• Maximum speed: 345 mph (300 knots, 555 km/h)
• Cruise speed: 242 mph (210 knots, 389 km/h)
• Range: 2,000 mi (1,700 nm, 3,000 km)
• Service ceiling: 39,000 ft (12,000 m)
• Rate of climb: ft/min (m/s)
• Wing loading: 58 lb/ft² (280 kg/m²)
• Power/mass: 0.076 hp/lb (55 W/kg)

Armament

• Guns: 8× .50 in (12.7 mm) machine guns
• Bombs: 10,000 lb (4,500 kg)

References

• Encyclopedia of American Aircraft
• USAF Museum on XB-33
• USAF Museum on XB-33A

External links

• XB-33 Blueprint
• XB-33A Blueprint

See also

Related development

• B-26 Marauder

Designation sequence

• XB-30 - XB-31 - B-32 - XB-33 - B-34 - YB-35 - B-36

Related lists

• List of military aircraft of the United States
• List of bomber aircraft

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "B-33 Super Marauder".