In 1927 a new class of all steel open wagon appeared in Western Australia. It was given the redundant K class code previously used for ballast wagons. A total of 375 wagons of this type were constructed in 1927/8. In 1935 nine wagons were converted to carry two cement containers by removing the sides and ends. They became class KC. They were all reconverted to K class standard in 1941. In 1936 K class wagons formed the basis for the JK class tankers. In this conversion the doors were plated over and a wooden roof fitted. This class existed for some time and conversions to and from JK are as listed below. In the early years the same wagons seem to have been involved each time and it may be that they ran as class K with sealed sides and no doors. From 1951 such wagons were classified KC (again) and used for coal traffic. Many former K class wagons were converted from JK to KC rather than back to class K. Eventually they were written off over a long period with one wagon (11102) being converted into an MS class sand wagon.

The photo at right by Peter Hopper shows two KC class wagons at the head of a coal train departing Pinjarra (RHWA collection)

1951	10617, 10626, 10635, 10665, 10688, 10699, 10726, 10752, 10756, 10800, 10835, 10858, 10997, 11002, 11006, 11030, 11067, 11088, 11095, 11101 ex JK
1952	10617, 10626, 10635, 10665, 10688, 10699, 10726, 10752, 10756, 10800, 10835, 10858, 10997, 11002, 11006, 11030, 11067, 11088, 11095, 11101 to JK
1953	10627, 10628, 10634, 10638, 10642, 10643, 10650, 10672, 10679, 10688, 10703, 10711, 10716, 10721, 10734, 10740, 10750, 10752, 10757, 10772, 10800, 10801, 10803, 10816, 10828, 10835, 10850, 10853, 10858, 10863, 10869, 10984, 10985, 10986, 10987, 10999, 11025, 11036, 11052, 11055, 11056, 11058, 11067, 11071, 11085, 11089, 11093, 11095, 11101, 11102 ex JK
1954	10627, 10628, 10634, 10638, 10642, 10643, 10650, 10672, 10679, 10688, 10703, 10711, 10716, 10721, 10734, 10740, 10750, 10752, 10757, 10772, 10800, 10801, 10803, 10816, 10828, 10850, 10853, 10858, 10863, 10869, 10984, 10985, 10987, 10999, 11052, 11055, 11056, 11058, 11067, 11071, 11085, 11101, 11102 to JK
1955	10617, 10627, 10635, 10642, 10647, 10652, 10663, 10672, 10675, 10679, 10688, 10710, 10716, 10721, 10727, 10734, 10745, 10750, 10756, 10757, 10766, 10768, 10772, 10791, 10796, 10798, 10801, 10803, 10816, 10818, 10827, 10828, 10850, 10858, 10863, 10869, 10984, 10985, 10987, 10999, 11005, 11006, 11022, 11024, 11055, 11056, 11058, 11060, 11067, 11071, 11085, 11100, 11101, 11102 ex JK
1956	10630/8, 10713, 10743, 10752, 11030, 11074, 11088 ex JK
1958	10626, 10628, 10631, 10634, 10643, 10644, 10650, 10654, 10695, 10699, 10701, 10703, 10726, 10738, 10740, 10762, 10774, 10813, 10822, 10853, 10867, 10994, 10997, 11002, 11052, 11053, 11057, 11066, 11080, 11081, 11096 ex JK
1959	10665, 10689, 10711, 10800, 11047 ex JK
1961	10627, 10663, 11030 to K
1962	10626, 10638, 10672, 10710, 10791, 10818, 10858, 11022, 11058, 11089 to K
1963	10688, 10734, 10756 to K, 10803 written off
1964	11002, 11101 to K 10628, 10652, 10679, 10695, 10743, 10745, 10766, 10801, 10827, 10999 written off
1965	10798 to K 10647, 10716, 100774, 10835, 10850, 10867, 10985, 10987, 11025, 11032, 11047, 11056, 11081, 11088 written off
1966	10617, 10642, 10644, 10654, 10701, 10703, 10711, 10713, 10726, 10727, 10740, 10796, 10800, 10822, 10828, 10869, 11005, 11053, 11060, 11067, 11080, 11093, 11096 written off
1967	10762, 10772, 10984, 10994, 11006, 11055 written off
1968	10650, 11085 written off
1969	11102 to MS
1970	10635, 10643, 10750, 10757, 10768, 10986, 11024, 11052, 11071 written off
1971	11095 written off
1972	11036 written off
1973	10816, 10863 written off
1974	10675, 10997, 11100 written off
1977	10665 written off
1978	10853, 11074 written off
1979	10630, 10631, 10634, 10689, 10699, 10721, 10738, 10752, 11066 written off

The WAGR outline diagram is shown below.