 In 1906 E 66 was built for the Incline but did not prove as successful as the six H locomotives and was retired in 1917.When the Rimutaka Tunnel opened in November 1955, the Wairarapa Line became the first in New Zealand to be fully dieselised as steam locomotives were unable to pass through the tunnel.Initially, DE and DG class diesels were employed, and they were soon joined by the DA class.