The South Australian Railways introduced 36 steel bodied country passenger cars between 1936 and 1941. Of these cars the last 24 built, entered service in 1940/41. They were all of a similar external appearance and the same overall length. 

16 were coded 700 to 715, these were Second class centre aisle cars. 4 were coded 750 to 753, these were Composite class centre aisle cars. 4 were coded 780 to 783, these First class centre aisle cars. 

Originally introduced with frameless full drop windows, they were progressively replaced with half drop chrome plated framed windows from the mid 1950s through to the very early 1960s.

Introduced in Hawthorn green and cream with black roofs up until the mid to late 1960s, when they were progressively repainted into Regal red and Silver to match the newer country stock.

In the early 1970s 4 cars were transferred to standard gauge to work between Broken Hill and Peterborough. Later in the early 1980s several cars were hired to Victorian Railways.

Many 700 series cars also saw service with West Coast Railway in Victoria, Steam Ranger in South Australia, North Rivers Railroad with Ritz Rail in Northern NSW.