Due to a shortage of suburban engines in the Sydney area and the availability of surplus
C79 class tender engines, it was decided to experimentally convert one of the tender locomotives to a tank type engine in 1896. The conversion proved successful and a further 19 had been converted at
Eveleigh Railway Workshops by 1902. Following the delivery of
C30 class locomotives from 1903, they were transferred to
Newcastle suburban traffic and when replaced there, were allocated minor roles such as working the
Carlingford,
Morpeth and
Warren branches. Two were sold to East Greta Mining & Railway Company, one to Ashtonfields Colliery,
Thornton and a fourth scrapped. As part of the
1924 reclassification scheme, the remaining 16 were reclassified as the Z13 class and renumbered 1301 to 1316. In later years, their main duties were working of the
Ballina branch, the
Picton to Mittagong Loop line, the
Yass Town branch and school trains on the
North Coast line from
Coffs Harbour to
Kempsey and
Casino to
Border Loop. ==Preservation==