He was responsible for the railway's early locomotive successes, such as the Iron Duke Class, and for establishing Swindon railway works.[143] James Grierson - Goods Manager (1857–1863), he then became the general manager (1863–1887) from which position he saw the railway through a period of expansion and the early gauge conversions.[61] Frederick Hawksworth - The last GWR Chief Mechanical Engineer (1941–1947).[3] Henry Lambert - The general manager (1887–1896) responsible for managing the final gauge conversion in 1892.[61] James Milne - General manager (1929–1947) who saw the GWR through World War II.[61] Sir Felix Pole - As general manager (1921–1929) he oversaw the Grouping of the South Wales railways into the GWR following the Railways Act 1921, and promoted the use of 20 ton wagons to bring efficiencies to the railway's coal trade.[61] Charles Spagnoletti - The GWR's Telegraph Superintendent (1855–1892) patented the Disc Block Telegraph Instrument that was used to safely control the dispatch of trains.