The first 30 7-carriage trains, known as the first series, were constructed in the United Kingdom by Gloucester Railway Carriage and Wagon Company, and delivered between 1956 and 1959.
The first series of "T" and "BT" trailers were built by Comeng (the first 10 in Sydney, the rest in Melbourne), and finished by Martin & King, with the remainder built at the Newport Workshops [REF].