 Then, just as the bogie appeared to be doomed to extinction on the GER, Holden introduced over the next three years new 4-2-2 and 4-4-0 passenger and 0-4-4 tank classes.Holden continued for thirteen years to fit his engines with stovepipe chimneys, and also with Thomas Worsdell's capacious cab, with its gracefully curved side-sheets.Although for a time he continued with the Worsdell three-ring boiler barrel, with the dome on the middle ring, before long he designed a two-ring boiler with the dome on the front ring, immediately behind the chimney.