 However, the locomotive was found to steam poorly under load using the system and was converted back to weir burner operation, with no further locomotives converted.By the late 1960s the J class was largely relegated to shunting at various country yards, with many losing their cowcatchers and gaining shunter's steps on the tender sides.The introduction of the Y class diesel electrics saw the J class superseded in this role, and in November 1967, J523 became the first J class to be scrapped.