WAGR Ja class
The Ja class resulted from the rebuilding of the J class at Midland Railway Workshops in 1907 to improve performance, fitting them with Q class boilers left over from Qa class conversions, the frames of the J class having to be extended to accommodate for the boilers. In this form, the locos steamed better and reportedly did good work on mixed trains. By 1913 the Ja designation was abolished reverting back to the J class as all original locos had been converted. All were withdrawn in early 1924 and after repairs were sold off into the timber industry.