Kapiti Line

Metlink's Kapiti Line^[2][3] is the electrified southern portion of the North Island Main Trunk Railway between New Zealand's capital city, Wellington, and Waikanae on the Kapiti Coast, operated by Tranz Metro on behalf of Greater Wellington Regional Council.^[2] Trains run frequently every day, with stops at 16 stations. Until 2011 it was known as the Paraparaumu Line.

Construction

The Kapiti Line was constructed by the Wellington and Manawatu Railway Company as part of its line between Wellington and Longburn, south of Palmerston North. It was built by a group of Wellington businessmen frustrated with the indecision of the government about the construction of a west coast route out of Wellington.^[4] Construction of the line began in September 1882 and followed a circuitous, steep route via Johnsonville. It was opened to Plimmerton in October 1885, and on 3 November 1886 the line was finished, with the final spike driven just north of Paraparaumu, at Otaihanga.^[5]

On 7 December 1908 the government acquired the Wellington and Manawatu Railway Company, and incorporated it into its national network as the southern portion of the North Island Main Trunk line.

Deviation and electrification

In 1928, work began on a deviation to avoid the difficult Johnsonville section of the line. This deviation had two significant tunnels between Kaiwharawhara and Tawa. It opened to freight on 24 July 1935 and to passengers on 19 June 1937. The Johnsonville section was retained as the Johnsonville Line.^[6]

The line from Wellington to Paekakariki was electrified from 24 July 1940 ^[7], primarily to avoid smoke nuisance in the new deviation's lengthy second tunnel, and to provide extra tractive effort on the Paekakariki Hill between Pukerua Bay and Paekakariki. Paekakariki was thus established as a major station where trains swapped from steam (later diesel) to electric motive power, and it was the northern terminus of the commuter line for many years. Electrification was extended to Paraparaumu on 7 May 1983.^[1]

Double track from Porirua to Mana was opened on 7 November 1960, with the line no longer following the curves of the shoreline bays north of Porirua. A new station and bridge at Paremata were required.^[8]

Operation

From electrification until the 1980s, the majority of commuter services on the line were operated by DM/D electric multiple units, with some carriage trains hauled by ED and EW electric locomotives, particularly at peak periods. ED and EW locomotives also hauled freight trains over this section until the tunnels between Pukerua Bay and Paekakariki were lowered in 1967 and DA diesel locomotives could be used into Wellington.

From 1982 the new EM/ET electric multiple units were delivered. They had been ordered to replace the wooden carriage trains hauled by electric locomotives on commuter services and largely displaced the DM/D units on the Paraparaumu Line.

By the 1980s, the ED and EW electric locomotives were not required for either freight trains or for commuter trains. They were retired due to age and lack of use, the EDs by 1981 and the EWs by 1988. From 2010 the introduction of the Matangi EMUs will provide extra passenger capacity, and enable the remaining DM/D EMUs to be withdrawn.

A proposal to extend the electrification to Waikanae was approved by the Greater Wellington Regional Council on 8 May 2007. This project included the double tracking of the single track line between MacKays Crossing (between Paekakariki and Paraparaumu) as far as the rail underbridge and river bridge south of Waikanae. The $90 million project started in December 2008, and was completed in 2011, with the first commuter trains to Waikanae on 20 February.^[3] Completion of the project was delayed to 2011 to minimise commuter disruption by working in the quiet end-of-year holiday period, according to ONTRACK program director David Gordon. The project involved 50 workers and 20 machines installing 600 traction poles in eight or nine metre deep holes, and laying 30 km of rail and 30,000 sleepers. The project allows commuter services from Waikanae every 15 minutes.^[9] The new Matangi electric multiple units will be used on the Kapiti Line from mid 2011.^[2] Paraparaumu and Waikanae stations were upgraded at a cost of more than $1 million each. Upgrading Waikanae station rather than moving it south of Elizabeth Street or providing a road underpass has been criticised locally, as frequent closing of the Elizabeth Street level crossing south of the station may increase traffic congestion in Waikanae.^[10]

The future

Proposals for new stations at Raumati, between MacKays Crossing and Paraparaumu, and Lindale, north of Paraparaumu near Otaihanga, are on hold, to be reconsidered after 2010, as it was claimed that there were problems affecting a station at Raumati (the provision of access to SH 1 and park-and-ride facilities) and an unstable hillside behind the line.^[11][12][13]

Further extension of the electrification 15km north from Waikanae to Otaki remains a possibility. A group known as "Save Kapiti" is actively campaigning for the extension.^[14] The Otaki Community Board also supports the extension of electrification.^[15] Provision has been made during road earthworks north of Waikanae for a future crossing loop between Peka Peka and Otaki.^[16]

The section between Pukerua Bay and Paekakariki may also be double tracked or replaced by a less steep deviation during the first half of the 21st century, although the present proposal is to daylight only the northernmost (No. 7) tunnel which is through rock, and have double track north from there.^[17]

See also

• List of Wellington railway stations

References

External links

• Auckland-Wellington Express between Porirua and Paremata, c1932
• Photo of Paraparaumu station and commuter parking
• Photos of Takapu Road station
• Photos of Redwood station
• Photos of Tawa station
• Photos of Linden station
• Ontrack: Kapiti Line upgrade project 2009-11