Redhen railcar (originally, Red Hen) was the nickname given to the 300 and 400 classes of diesel-hydraulic railcars designed and built by the South Australian Railways’ Islington Railway Workshops between 1955 and 1971. The class remained in service until 1996 and remain a nostalgic part of South Australian culture; some are operated by the SteamRanger Heritage Railway and other railway preservation entities. Configuration The Redhens comprised two designs: 300 class had a driving cab at one end of each railcar. These needed to run in two-car formations. 400 class had driving cabs at both ends as well as guard units at the B end, and could be used as a single car when needed, or in multiple with other railcars to make up longer trains. In addition, there were a number of unpowered trailer cars, the 820 and 860 classes. These had been modified from steam-era suburban carriages and were used with the Redhens between 1955 and 1987. History Construction The first Redhens were introduced by the South Australian Railways in October 1955 to replace ageing suburban steam locomotive hauled trains in Adelaide. Construction of Redhen vehicles continued until 1971, when the latest examples were built to supersede 1920s-era diesel railcars. The Redhens were built in three batches. The overall design of the railcars was very similar, but there were differences in detail between the batches. Several railcars in the 300 class were re-numbered later in life, taking on the numbers of written-off or modified units. The exterior of the units was always painted red, with variations in the colour of roofs and bogies over the years. The interior design and layout remained largely unchanged throughout their life. Some 300 class units were modified to provide guard's accommodation or space for bikes when the 860 class trailers were withdrawn in 1987. This slightly reduced the seating capacity of these modified cars. Deployment When first introduced, all the 300 class Redhens were formed as 3-car consists, comprising an 820 or 860 class trailer sandwiched between two powered 300 class railcars. In peak hours, two sets were coupled together to form 6-car trains. On rare occasions, at times of heavy traffic demand, trains of Redhens could be up to nine cars long. Instead of building trailer cars to work with the 300 class cars, the South Australian Railways chose to convert existing rolling stock. To operate with 300 to 347, five 800