They were nicknamed Dreadnoughts, after a powerful British warship of the day, the Sydney press referred to them as Toastracks as all the seats were transverse or crossbench.

[1][2] Between 1918 and 1946, eleven (855, 935, 943, 1007, 1089, 1170, 1241, 1372, 1383 and 1451) were rebuilt to resemble the P-class trams when heavy body repairs were required and reclassified as the O/P class.

In the centre are the four closed sections, accessible to the street via sliding doors and fitted with cross bench timber seats.

On either side of these are the two open compartments, each fitted with two facing cross bench seats with metal armrests.

They were especially suited to venues such as race meetings, sporting matches and the Royal Easter Show as they could be emptied and filled quickly by means of the numerous doorways.