The B-26A was externally identical to the B-26 which preceded it. However, there were some significant internal differences.
The B-26 differed from the B-26 primarily in having an extra ferry fuel tank installed in the rear bomb bay. Additional Dural armor-plating was fitted, and Goodyear rubber self-sealing tanks replaced the original Mareng ones. A 24-volt electrical system was provided and a low-pressure oxygen system was fitted. The B-26A also had a shackle for a 22-inch torpedo underneath the fuselage. These changes added 2000 pounds to the weight. A total of 30 B-26As were built, plus an additional 49 which went to the RAF as Marauder I (FK112/FK160).
The first 30 B-26As were delivered with R-2800-5 engines built under license by Ford. However, because of critical shortages in these engines, the Air Force ordered Pratt & Whitney to divert 1850 hp R-2800 S1AG4s to Martin. These engines were redesignated R-2800-39 and were used on the production line starting with 41-7366. These Marauders were designated B-26A-1, but they were otherwise idential to the B-26A. A total of 109 were built. 19 were delivered to the RAF under Lend-Lease as Marauder IA (FK362/FK380).
Weights had increased to 21,741 pounds empty, 32,200 pounds loaded. Ferry range was 2600 miles with 1462 gallons of fuel.
The first B-26A (41-7345) was delivered in October of 1941.
In 1942, many of the earlier B-26s were retrofitted with the extra ferry Tanks introduced on the B-26A, thus being brought up to B-26A standards. Some of the B-26/B-26A had the 0.30-inch nose gun replaced with a 0.50-inch gun.
The name Marauder was assigned to the B-26 in October of 1941. Initially, the name Martian had been seriously considered.
41-7345/7365 Martin B-26A Marauder 41-7366/7367 Martin B-26A-1 Marauder 41-7368 Martin B-26A Marauder 41-7369/7430 Martin B-26A-1 Marauder 41-7431 Martin B-26A Marauder 41-7432/7476 Martin B-26A-1 Marauder 41-7477/7483 Martin B-26A-1 Marauder
Engines: Two Pratt & Whitney R-2800-5 Double Wasp air cooled radial engines, rated at 1850 hp each for takeoff, 1500 hp at 14,100 feet. Performance: Maximum speed 313 mph at 15,000 feet. Cruising speed 243 mph. Service ceiling 23,500 feet. Range was 1000 miles at 265 mph with a 3000-pound bombload. 2600 miles maximum range. Weights: 21,741 pounds empty, 28,367 pounds gross, 33,022 pounds maximum. Dimensions: Wingspan 65 feet 0 inches, length 58 feet 3 inches, height 19 feet 10 inches, wing area 602 square feet. Armament: One flexible 0.30-inch machine gun installed in the tip of a transparent nose cone and operated by the bombardier. Two 0.50-inch machine guns in a Martin-designed dorsal turret located behind the bomb bay just ahead of the tail. One 0.30-inch flexible machine gun was installed in a tunnel position in the lower rear fuselage. One flexible 0.50-inch machine installed in a tail position. The maximum bombload was 5800 pounds.