Stephenson and Dodds Locomotive
1815 This engine was patented on the 28th of February by Ralph Dodds, chief viewer to the Grand Allies Collieries at Killingworth, and George Stephenson, for improvements in locomotive engines.
After the engine had been at work for some time, young Isaac Dodds saw that the method of coupling the wheels was imperfect; he obtained two spinning wheels, and applied a coupling-rod to enable him to work both with one treadle, to do which necessitated a return crank. Having got it to work satisfactorily, he showed it to his uncle, Ralph Dodds, and to Stephenson, who afterwards adopted the coupling-rod.