 This left him with a double-engined four-wheel—drive tractor capable of producing more power and outperforming any of the conventional tractors on the UK market at the time.Local Fordson dealers Ernest Doe & Sons agreed to build an improved version, the first one was completed in 1958 and called the Doe Dual Power, later changed to Doe Dual Drive and abbreviated to Triple-D.The first Doe Triple-D used two Fordson Power Major units producing , the later Triple-D 130 used two Ford 5000 tractors increasing the power output to over and the Triple-D 150 was based on Ford Force 5000 tractors producing .