Between 1921 and 1929, 258 P class trams were built by Randwick Tramway Workshops, Meadowbank Manufacturing Company, and the Walsh Island Dockyard.

They were a big improvement over the O-class in that all compartments offered protection from bad weather on both sides of the bodies when running.

[1] The P-class trams were based at all depots on the main system except Rushcutters Bay, but worked to the Sydney Stadium, just past the depot between 1947 and 1959 out of Waverley and Dowling Street for special events, plus out to Watsons Bay for picnic specials.

One tram, 1691, had a narrow corridor cut through the cross bench bulkheads, and was then the sole member of the PR class.

[1][2] Six have been preserved: Media related to Sydney P-Class Tram at Wikimedia Commons