Wellington-Longburn portion of the New Plymouth Express). After the acquisition of the WMR, the Napier Express was re-routed to the quicker west coast route in early 1909 and the Wairarapa Mail was introduced to provide a regular service through the Wairarapa to Woodville. In 1936, RM class Wairarapa railcars were introduced; these were designed to operate at speed over the Rimutaka Incline and provided a much quicker service to Wellington and local Wairarapa services. They originally augmented the Wairarapa Mail but replaced it in 1948. Carriage trains operated only at peak times of the year when the railcar capacity was exceeded; in 1955, the Incline's closure meant the Wairarapa railcars were withdrawn and 88 seater railcars were introduced, boosting capacity at off-peak times. One Wairarapa railcar has survived and is currently under restoration by the Pahiatua Railcar Society. Mixed trains also operated until the 1950s. In the 1950s, the Hutt Valley line was electrified using the 1500 V DC system already operating from Wellington to Johnsonville and Paekakariki. The electrification was opened to Taitā on 12 October 1953 and Upper Hutt on 24 July 1955, allowing for a more intensive suburban commuter service to Wellington. Originally operated by DM/D class electric multiple units and carriage trains hauled by ED and EW class electric locomotives, the carriage trains and many of the DM/D units were phased out upon the introduction of the "Ganz-Mavag" EM/ET class units in the early 1980s. The "Matangi" FP/FT class was introduced on the Hutt Valley Line in 2011–12, initially relegating the Ganz Mavag units to peak services only before being completely replacing them from 2015. Railcar services were withdrawn in 1977, and carriage trains were re-instated progressively from early 1964. Until 1963, a railcar service operated on Friday evenings between Masterton and Woodville, and in December that year the decision was taken to replace the morning railcar to Wellington with a carriage train as over 200 passengers wished to use the railcar service that had a capacity of just 176. The final railcar service was replaced by carriage trains in December 1977; some of the carriage trains from this point until the mid-1980s were made up of de-motorised former 88-seater railcars known as "grassgrubs" in New Zealand railfan jargon. Passenger services through the lowly populated northern Wairarapa survived due to the poor roads in the area, but as they were improved, demand for the trains declined.