Adelaide's Red Hens

Red Hens seen working the Adelaide Hills line (Ian Thralfall)

Another of the quaint Australian railway motive power items from the 1950s, the Red Hen diesel hydraulic railcars were introduced in October 1955 and used on the Adelaide suburban system;  eventually they replaced even older 1920s-era diesel railcars known as Barwell Bulls.

They were built at SAR's Islington Workshops and there were two variants:
* The 300-class with a driving cab at one end of each car - which needed to run as a minimum of 2-car trains - of which 74 were built, fleet numbers 300–373;
* The 400-class with driving cabs at both ends - which could be used as a single car or in multiple with other cars to make up longer trains - of which 37 were built, fleet numbers 400–436.

All cars were 20 metres (65 ft 7 in) long, 3.05 metres (10 ft) wide, 4.27 metres (14 ft) high and for the 1,600 mm (5 ft 3 in) broad gauge.

There were a number of unpowered trailer cars, designated 820-class or 860-class which had been modified from steam-era suburban carriages and were used with the Red Hens between 1955 and 1987.

The Red Hens were built in three batches with the same general design, but with detail differences. Several of the 300 class were re-numbered later in life, taking on the numbers of written-off or modified units.  The exteriors were 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300-class units were modified to provide guard’s accommodation or space for bikes when the 860-class trailers had been withdrawn in 1987. This slightly reduced the seating capacity of these modified cars.

Engines fitted were:

300-341 and 400-419:
2 x GM model 6/71–6086 inclined 2-stroke diesels, 6.97 litre, 163 kilowatts (219 hp) at 2100 rpm.

342-361:
2 x Rolls Royce model C6SFLH horizontal 4-stroke diesels with supercharger, 12.17 litre, 170 kW (228 hp) at 1850 rpm

362-373 and 420-436:
2 x GM model 6/71–6086 inclined 2-stroke diesels, 6.97 litre, 157 kW (211 hp) at 2100 rpm

The Red Hens were withdrawn and scrapped between 1987 and 1996, except for a few sent to various museums.