The 1016 Class consisted of sixty double framed 0-6-0 saddle tank locomotives designed by George Armstrong and built at the Wolverhampton Works of the Great Western Railway between 1867 and 1871. Like the earlier 302 Class of Joseph Armstrong, the 1016s had 4 ft 6 in (1.372 m) wheels and a 15 ft 6 in (4.72 m) wheelbase, dimensions that would remain traditional for the larger GWR pannier tanks right through to Charles Collett's 5700 Class, and with little change to Frederick Hawksworth's 9400 Class of 1947.