Johnsonville Branch

The line was built in the 1880s as part of the private Wellington and Manawatu Railway Company line to connect Wellington to Longburn. Construction started in 1879, and the first section, to Paremata, opened on 24 September 1885. The line became part of the North Island Main Trunk when the government bought the WMR in December 1908.

The line was used by railway workers from the Tarikaka Settlement in Ngaio, including early shift workers who needed to fire up steam locomotives at the Wellington depot.

Two experimental RM class railcars were briefly used on the line as NZR sought to develop economically viable railcar technology. The Westinghouse railcar was introduced in 1914 and served through to 1917. The Thomas Transmission railcar was introduced in 1916 and operated sporadically into the early 1920s. Both railcars struggled on the steep grades and revealed that further advances were needed to make railcars suitable to New Zealand's conditions. Trains going north often used banking engines on the steep grade from Lambton to Ngaio and sometimes when going south from Johnsonville to Raroa.[3]

The line became a branch when the Tawa Flat deviation of the NIMT opened to passengers in 1937, and was sometimes called The Hill (in NZR jargon). The line was electrified at 1500 V DC overhead supply, and the new service with the new English Electric DM/D class electric multiple units service started from Monday 4 July 1938, after an opening ceremony on 2 July. The units normally operated as two-car motor/trailer sets, or four-car sets in peak hours. Additional DM/D class units were ordered for the line in 1942 and supplied in 1946.

The line was terminated in Johnsonville, about 100 m beyond the end of the current line: the State Highway 1 motorway on-ramp follows the route of the old line. Ngaio and Khandallah stations already had crossing loops, and new stations at Awarua Street and Simla Crescent plus a third crossing loop (without passenger platforms) at Wadestown between No. 3 and No. 4 tunnels were added. The two new stations had been used by steam trains from 10 January 1938, although only some local trains stopped there (on request). Even with two additional stops the time to Johnsonville was now 19 minutes either way; previously with steam operation trains took 25 minutes up and 21 minutes down.[4] [5]

Stations were added at Raroa (1940), Box Hill (1956) and Crofton Downs (1963).

The line was reviewed in 1984, 1993 and 2006–07 to consider either closing or upgrading it, without any significant changes being made.

A half-hourly service runs daily, augmented to a quarter-hourly service at peak periods.

The line has been passenger-only since the termination of livestock trains for an abattoir in the Ngauranga Gorge. The livestock were originally driven on foot through Johnsonville streets from a stockyard adjacent to the station, but after protests sidings near Raroa were opened on 2 February 1958. The livestock traffic ceased about 1973, though the sidings at Raroa were not lifted until about 1982. Because of the sharp curves on the line, EW class electric locomotives were used for livestock trains instead of the earlier ED class locomotives, which were hard on the track with their long rigid wheelbase.

The line is single track through very steep terrain rising 150 m above sea level in its 10 km length, with the highest point (152 m) at the north end of Kaka Tunnel. The ruling grade is 1 in 36, with long sections from Wellington to Crofton Downs and Khandallah of 1 in 40. There are seven narrow tunnels, six bridges, and three passing loops There are three level crossings with half-barriers; at the Simla Crescent and Khandallah stations, and at Fraser Avenue between Khandallah and Raroa stations (the Fraser Avenue crossing was last to get barriers as well as bells, in 2009). There is a private rail crossing to a house immediately south of the Fraser Avenue crossing; and a pedestrian crossing from Burma Road to Poona Street, Khandallah between the Khandallah station and the Rangoon Street road overbridge. Pedestrians can also cross the line at the Ngaio station.

The signals were operated by the trains, a standard SLA Absolute Block System; the first train at a crossing station or siding (Wadestown, Ngaio and Khandallah) claimed the next block (if two arranged simultaneously the up train got priority as there was a 5 second delay for the down train). The system was revised in July 1969; the second platform siding at Johnsonville was removed and the goods yard (since removed) became a switch-locked siding. Signal boxes were initially retained at Ngaio and Khandallah. Up to 1984 when the line was truncated and the station was moved to accommodate the mall, the station had two sidings either side of the station platform and the preferred platform was alternated every 12 hours to equalise usage.[6]

The Wellington City Council let a $1.7m tender to replace the Rangoon Street single-lane overbridge of c1906, which crosses the Johnsonville line, with a two-lane bridge.[7][8] Work commenced in June 2008 and was completed by December 2008.[9]

Three traction substations along the line take electricity from Wellington Electricity's 11,000-volt distribution network and transform and rectify it to 1500-volt direct current for the overhead traction lines. The substations are located at Wellington (shared with the Kapiti and Hutt Valley Lines), Ngaio and Khandallah.

The names of the tunnels and their length in feet[10] and metres[11] are:

A southbound DM class EMU just south of Raroa Railway Station on the Johnsonville Line in 2007. The last of the DM class EMUs was withdrawn from the line in February 2012.

Due to significant mechanical difficulties being experienced by Tranz Metro in keeping the DM/D EMUs in service, several units were withdrawn from service in February 2012. Buses were added to supplement the remaining service capacity pending the planned introduction of the FT/FP "Matangi" EMUs on 19 March 2012.[22] The first Matangi service was the 11:02 departure from Wellington, which passed the last English Electric service on the line at Ngaio station.[23]

The new Matangi EMUs struggled on the Johnsonville Line with rail track squeal and to maintain the schedule used for the English Electrics especially in wet conditions.[24] To improve schedule reliability, the Johnsonville Line timetable was initially changed to a longer morning peak journey time of 22 minutes to Wellington and 26 minutes to Johnsonville[25] and it is now 23 minutes and 28 minutes.[26]

The proposed redevelopment of the Johnsonville Town Centre was to include improvements to the rail and bus terminal at Johnsonville; the terminal is now referred to as the Johnsonville Hub.

The Broderick Road overbridge immediately south of the Johnsonville Railway Station was upgraded by widening and lengthening in 2015 to include cycle lanes and extra road lanes over it. [27] Provision is made for dual tracks underneath (formerly one track) into the station, as requested by the Greater Wellington Regional Council for future double-tracking. [28]

Proposed infrastructure upgrades for the line include overhead line and mast replacement, sleeper replacement in tunnels and stabilisation of high risk slopes; to be completed in 2022.[29][30]

• New and old units on the Johnsonville Line, 19 March 2012
• Photo of Main Trunk express starting the climb from Thorndon with a banking engine in 1909
• "Photos of stations on line, 1938". The Evening Post in Papers Past. 2 July 1938.
• "Photo of unit in Ngaio Gorge, 1949". Archives NZ. 1949.
• "Wellington power supply upgrades (2009–2011)". KiwiRail. Retrieved 19 February 2012.
• Johnsonville Line: Photos, Signalling
• Photo of one of the last main line trains to enter Johnsonville c1938 from The New Zealand Railways Magazine as republished by the NZETC
• Photo of arrival of the first unit at Johnsonville 1938 from The New Zealand Railways Magazine as republished by the NZETC
• Photo of Johnsonville units at Wellington station c1939 from The New Zealand Railways Magazine as republished by the NZETC
• Photo of multiple unit on the line c1940 from The New Zealand Railways Magazine as republished by the NZETC
• A flashlight photo of passengers inside a unit c1938 from The New Zealand Railways Magazine as republished by the NZETC
• Scene from a loco cab running downhill from Johnsonville c1930 from The New Zealand Railways Magazine as republished by the NZETC
• North Wellington Public Transport Study
• Railways of New Zealand: Wellington & Manawatu Railway
• Invitation to Opening (NZR Publicity picture)
• "Views from a train on the new line (photos)". The Evening Post in Papers Past. 20 May 1939.