
This is The East Coast Main Trunk Railway line out of Hamilton. This line originally ran between Hamilton and Taneatua via Tauranga, connecting the Waikato with the Bay of Plenty. The ECMT now runs between Hamilton and Kawerau, with a branch line to Taneatua from the junction at Hawkens. The line is built to narrow gauge of 1067 mm (3 ft 6 in), the uniform gauge in New Zealand.
When the line opened to its terminus at Taneatua, the Taneatua Express ran from Auckland. The service took 12 hours, later reduced to 10½ hours, and ran two or three times weekly. The last train ran on 7 February 1959, and was replaced by a railcar service as far as Te Puke, due to negligible traffic to Taneatua. The railway struggled to compete with private cars and the service was withdrawn on 11 September 1967. Other than special excursions, there were no passenger services until 1991.
In 1991, the Kaimai Express started and ran to Tauranga. Along with the Geyserland Express it used the Silver Fern railcars that had been used on the North Island Main Trunk Line. The first train ran on 9 December 1991, running a morning service from Tauranga to Auckland and afternoon service from Auckland to Tauranga, taking 3½ hours. The times changed in 2000 to enable the introduction of the Waikato Connection commuter service between Hamilton and Auckland. In 2001, it was announced that the service was too uneconomic to continue, and the last service was on 7 October 2001. It is now used for freight only.
Source: Wikipedia