Two major reasons were the impetus for the construction of the Hutt Valley Branch between Petone and Waterloo: first, the Petone Workshops had reached the end of their useful life; second, with increasing traffic demands on the line between Petone and Haywards and the lack of room to double-track the line on its existing route meant a new mainline had to be built. The line was surveyed between 1924 and 1925, with a short industrial branch leaving the Hutt Valley Branch at Woburn to serve the new Hutt Workshops. On 26 May 1927 the rails reached Waterloo, which was then in the middle of open fields. This station was the terminus of the Hutt Valley Branch line until an extension north to Naenae was opened in 1946. The station was opened with automatic, three-aspect colour light signals which had been standard since 1924. It was always intended that Waterloo would one day serve a major population centre which, in the years following World War II and the population boom that ensued, was proved correct. Significant urban development of the Hutt Valley in the 1940s led to the decision in February 1946 to commence electrification in 1949 and to operate electric train between Waterloo and Wellington from August 1953. Until the connection of the Hutt Valley Branch to the Wairarapa Line and its opening as the new mainline on 1 March 1954, Waterloo served only suburban passenger services, with Upper Hutt and Wairarapa trains continuing to use the old line between Haywards and Petone on the western side of the Hutt Valley. In 1986, as a result of the Hutt Valley Transport Study, Waterloo was designated an interchange for bus and rail services in preference to Woburn, which had previously had this role. It was felt that Waterloo was a more logical choice as it was closer to centres of residential and commercial interest, had sufficient room for bus platforms to be installed, and was not burdened with other operational requirements such as Woburn being the junction with the Gracefield Branch, with its loops and sidings. The new interchange facility at Waterloo was opened on 26 November 1988 and fully integrated with all the new public transport routes and timetables by the following March.
Services
Rail
, on behalf of the Greater Wellington Regional Council, operates Hutt Valley Line electric suburban services between Wellington and Upper Hutt via Waterloo. It also operates the Wairarapa Connection diesel-hauled service between Wellington and Masterton via Waterloo. The basic daytime off-peak timetable is:
3 trains per hour Hutt Valley Line services to Wellington, stopping all stations.
3 tph Hutt Valley Line services to Upper Hutt, stopping all stations.
Two Wairarapa Connection services to Wellington, stopping Petone only.
Two Wairarapa Connection services to Masterton, stopping all stations from Upper Hutt.
The basic morning peak timetable is:
6 tph Hutt Valley Line to Wellington, split:
*3 tph stopping all stations to Petone
*3 tph non-stop
2 tph Hutt Valley Line to Upper Hutt, stopping all stations
Three Wairarapa Connection services to Wellington, stopping Petone only.
Bus
bus routes 121, 130, 150, 160 and 170 serve Waterloo.
