Martin XB-48

The Martin XB-48 was an American medium jet bomber developed in the mid-1940s as a backup in case the Boeing B-47 Stratojet ran into trouble, and it competed with that design. It came from a 1944 War Department requirement for medium bombers and belonged to the transitional Class of 1945, combining the power of turbojets with World War II airframe design, notably unswept wings, with a round fuselage showing the influence of Martin's B-26 Marauder. The low thrust of the turbojets then available meant six engines were needed, carried in two unusually wide three-engined nacelles. The B-47 proved the superior design, the XB-48 never saw production or active duty, and only two prototypes were built.