Martin XB-33 Super Marauder

XB-33 Super Marauder
XB-33 Super Marauder
	Schematic blueprint drawing of the XB-33.
General information
Type	Medium bomber
National origin	United States
Manufacturer	Glenn L. Martin Company
Status	Cancelled 25 November 1942
Primary user	United States Army Air Forces (intended)
Number built	None
History
Developed from	Martin B-26 Marauder

The Martin XB-33 Super Marauder was a proposed World War II American bomber aircraft. It was designed by the Glenn L. Martin Company as the Martin Model 190 and was a high-altitude derivative of the company's B-26 Marauder. Two different designs were developed, first as a twin-engined aircraft and then as a four-engined aircraft. The four-engined version was ordered by the United States Army Air Forces, but the program was cancelled before any aircraft were built.

Design and development

XB-33

The first version of the B-33 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 (1,814 kg) of bombs. Soon after design of the XB-33 began it became clear that a twin-engined aircraft would not achieve the performance requested by the army. The company moved on to developing a larger four-engined design, the XB-33A.

XB-33A

Following the abandonment of the original twin-engined design, the company continued to design a larger four-engined aircraft, and two prototypes were ordered by the USAAF as the XB-33A; its bombload was to have been 12,000 lb (5,443 kg), as much as that of the B-24 Liberator, the heaviest US bomber flown in combat prior to the B-29.

The original XB-33 design was to have been powered by the R-3350, the redesigned XB-33A was to have used Wright R-2600 engines. The main reason for this was the 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 USAAF placed an order for 400 B-33As, to be built at the government-owned plant in Omaha, Nebraska, operated by Martin. On November 25, 1942, the project was cancelled to allow the Omaha plant to concentrate on manufacturing B-29s.

Variants

XB-33: Prototype medium bomber powered by two 1,800 hp (1,343 kW) R-3350 engines, two ordered and cancelled.^[1]
XB-33A: Prototype medium bomber powered by four 1,800 hp (1,343 kW) R-2600-15 engines, two ordered and cancelled.^[1]
B-33A Super Marauder: Production variant of XB-33A, 400 ordered and cancelled.^[1]

Specifications (B-33A, as designed)

General characteristics

Crew: seven
Length: 79 ft 10 in (24.3 m)
Wingspan: 134 ft 0 in (40.8 m)
Height: 24 ft 0 in (7.32 m)
Wing area: 1,646 sq ft (153 m²)
Empty weight: 85,000 lb (39,000 kg)
Gross weight: 95,000 lb (43,000 kg)
Powerplant: 4 × Wright R-2600-15 radial engines, 1,800 hp (1,300 kW) each

Performance

Maximum speed: 345 mph (555 km/h, 300 kn)
Cruise speed: 242 mph (389 km/h, 210 kn)
Range: 2,000 mi (3,000 km, 1,700 nmi)
Service ceiling: 39,000 ft (12,000 m)
Wing loading: 58 lb/sq ft (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

Notes

^ ^a ^b ^c Andrade 1979, p 51

Bibliography

Encyclopedia of American Aircraft
Andrade, John (1979). U.S.Military Aircraft Designations and Serials since 1909. Midland Counties Publications. ISBN 0-904597-22-9.

[Andrade_1979,_p_51-1] Andrade 1979, p 51

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