The establishment of a new locomotive depot allowed for assistant engines to be attached there (instead of Penrith) for the climb to Katoomba. The engines at Valley Heights not only piloted over the longest distance in NSW, but also had the distinction of having to operate over the longest continual and most steeply graded mainline in Australia. During the peak of the steam era an average of 30 trains during any 24 hour period required a pilot engine from the depot. From 1913, Valley Heights became an important railway centre and most of the buildings that exist in the depot date from the opening and early period; the ten stall sector roundhouse, a 60' turntable and new offices and sidings were built in 1913, followed by a Station Master's residence and a night-officer's house in 1914. The depot also includes a water tank and archaeological remains of various structures. The depot continued in operation as a steam locomotive depot until February 1957 when electric locomotive running commenced. The change to electric traction (46 class locomotives) was associated with the electrification of the Main Western line to Lithgow which was completed in late 1957. While the role of the depot in providing pilot engines remained unchanged, the now redundant steam servicing facilities were removed. The pilot engine role of the depot continued into the early 1980s until the placing in service of more powerful electric locomotives (the 85 and 86 classes). Over the intervening years the role of the depot had expanded to include servicing, repair and overhaul of electric locomotives and also goods wagons. In 1989 the depot was closed and was used to store and service track maintenance material until 1993 when the State Rail Authority (SRA) vacated the site. In 1994 the Blue Mountains Division of the New South Wales Rail Transport Museum established the Valley Heights Locomotive Depot Railway Museum with the aim of preserving the depot to provide historical, educational and recreational facilities and opportunities for the benefit of the Blue Mountains community and visitor to the region. The Valley Heights Steam Tramway was established in 1997 by the Stream Tram and Railway Preservation (Co-Op) Society Limited. The locomotive depot continues to be occupied by the NSW Rail Transport Museum. Valley Heights has one island platform with two sides. It is serviced by NSW TrainLink Blue Mountains Line services travelling from Sydney Central to Lithgow. The station precinct comprises a type 11, initial island/side platform brick station building, erected in 1902; a brick lamp room/store, erected in 1902; a signal box, erected in 1910.