 In 1943 the US Navy invited proposals for a new multi @-@ purpose bomber and selected four designs in September : the Curtiss XBTC , Douglas XBT2D Skyraider , Kaiser @-@ Fleetwings BTK and the Martin XBTM . Martin was tasked to provide a back @-@ up to the Curtiss design which had been selected as a replacement to the Curtiss SB2C Helldiver . Due to the US Navy 's concern that the Curtiss design was overly complex and that the company 's record was particularly poor during the Helldiver 's development , Martin was instructed to create an " unexperimental " design that would be a reliable platform for the Pratt & Whitney R @-@ 4360 Wasp Major radial engine that powered both aircraft . Two prototypes were ordered from Martin on 31 May 1944 with the internal designation of Model 210 . 
