Talk:North Island Main Trunk

Gosh I didn't realise that so many stops had been chopped, and it is still on going. ThanX for the ammendments... NevilleDNZ Wed Apr 27 11:14:38 SGT 2005

yes its interesting how once the backbone of leased land containing the fibre optic communications network across NZ was sold, the transport function was sold off and left to shrink away. We need some info about how much that electrification cost, (wasnt it $1200 Million?) and how much the whole thing was sold for. we could also do with some idea of who bought it, what their communications and entertainment interests were and are, and how they are interrelated, and who has bought and sold the various parts since. personally i think it was really dumb, but it was one answer to a big set of issues facing nz at the time.moza 09:59, 29 April 2006 (UTC)Reply

Well, with the price of fuel going through the roof, it will be interesting to see if some of the "Think Big" schemes dreamt up during the original "Oil Crisis" will suddenly save NZ's collective butts. Yee gads.... petrol is still cheaper then Cocacola. NevilleDNZ 10:18, 29 April 2006 (UTC)Reply

Quick question - is it 1500 V DC overhead from Wellington to Paraparaumu, then non-electrified to Palmerston North, and 25kV AC to Hamilton, with the rest (to Auckland) unelectrified ... ??? Pickle 18:43, 1 July 2006 (UTC)Reply

• Crazy as it sounds, that's correct. The proposals to electrify the Auckland suburban system (if they ever go ahead) only extend so far as the system currently operates - which of course is only just south of Auckland. In Wellington the proposals are to extend the electrification north a couple of Kms... so maybe in 100 years they'll meet up! --Lholden 02:20, 2 July 2006 (UTC)Reply

• Yes, and most diesel-hauled trains go right into Wellington are diesel-hauled over the electrified section north (since the track was dropped in the tunnels north of Pukerua Bay to accomodate higher containers and the DA diesels) and from the Wairarapa via the Hutt suburban electric section. Suburban electrification to extend to Waikanae (?) with new stations at Raumati, Lindale. Hugo999 05:09, 13 January 2007 (UTC)Reply

• PS: The 1500 V DC lines got north as far as Paraparaumu in 1983 and Waikanae in 2011. But the section from Wellington to Paekakariki was electrified in 1940 because of the long Tawa No 2 Tunnel; that's long before 25kV AC at mains frequency was thought of! South of Auckland the 25kV AC is to go south to Tuakau soon so lessening the gap to Hamilton! Hugo999 (talk) 13:21, 6 April 2020 (UTC)Reply

• Hah, this is a funny reminder of a 2006 comment. How things change - Auckland electrification went ahead, now it's going to be extended south to Pukekohe, and hopefully further south again. There's an active campaign for electrification to be extended north from Waikanae to Otaki and maybe even Levin... and perhaps Palmerston North. Just need some of these to run AC/DC... --LJ Holden 20:21, 6 April 2020 (UTC)Reply

• Yes but those Japanese locomotives are for two AC voltages (25 kV and 20 kV (50 or 60 hz) as used on Japanese narrow-gauge lines (ie not Shinkansen high-speed). Like the British locos with 6.25 kV or 25 kV AC before they relaxed the required clearances (eg British Rail Class 81). What would be needed are dual-voltage AC/DC locos like the JR Freight Class EH500 or the British Rail Class 92. Doubt if extension of electrification to Otaki or Levin is likely; with different EMUs with toilets required for a trip of over an hour. The Capital Connection to Palmerston North is only one train daily, unlike the Wairarapa Connection. The GWRC proposals for electro-diesel hybrids (diesel/overhead) to replace those two trains was turned down (only $415k!). And with electrification of the section Papakura-Pukekohe proposed, the ACC has dropped the proposal to buy battery/overhead EMUs from CAF Spain and will get more CAF EMUs instead. PS: We looked at the Matangi depot in Wellington when a second batch was announced to replace the Ganz-Mavags and someone asked whether they would have got 25 kV AC Matangis if there had been one big order for them (but probably too many clearance problems). With an all-Matangi fleet the voltage was increased from 1600v to 1700v to increase the power available. Hugo999 (talk) 04:33, 10 April 2020 (UTC)Reply

Sorry wrong Japanese locos. I knew it was EH something. Is there any reference anywhere for the increase in voltage? I've seen it mentioned but never read anything "official" that could be cited. --LJ Holden 09:01, 10 April 2020 (UTC)Reply

• 1600 and 1700 volts are both well within the normal tolerance for a nominally 1500-volt traction supply. Likewise, the mains voltage in New Zealand is nominally 230 volts, but 220 volts and 240 volts are both within normal tolerance. Therefore, the exact voltage doesn't matter.Lcmortensen (mailbox) 03:49, 11 April 2020 (UTC)Reply
• Ok, but user:Hugo999 seems to be saying that the nominal voltage in Wellington was 1600v and was increased to 1700v. There must be a technical reference for that somewhere? The tolerances must've increased. LJ Holden 05:19, 11 April 2020 (UTC)Reply

• 1500-volt traction equipment is designed for a maximum continuous voltage of 1800 volts. I don't believe they build traction substations for nominal 1700 V; if they did, it would be a special order and prohibitively expensive. I presume the traction substation transformers are fitted with tap changers, so increasing the nominal voltage would be as simple as changing to a different tap. Lcmortensen (mailbox) 05:43, 11 April 2020 (UTC)Reply

• Will look for a reference for the working voltage (at the substation) for the Matangis being raised from 1600V to 1700V when I can access magazines in libraries again! I think the minimum voltage was 1200V for earlier rolling stock, but doubt if 1800 V was the upper limit; an old NZR file in Archives for the Otira locos (also English Electric) suggested that 1600V was tried but was too much for some auxiliary loco items eg blowers. Re the 230V supply; not sure about the exact NZ limits but a 1953 British textbook (Starr) says the limit there was raised from +/- 4% to +/- 6% "in order that rural lines may be erected at a reasonable cost" (ie the lower limit is more important). Hugo999 (talk) 22:11, 13 April 2020 (UTC)Reply
• Tracksafe^[1] and Kiwirail still refer to it as 1500v,^[2][3] but TAIC,^[4] NZTA^[5] and Treasury say 1600v.^[6] Maybe change the 1600v and 1500v figures to 1500v nominal? Johnragla (talk) 02:05, 28 November 2021 (UTC)Reply

I've just added a link to a new feature on our NZHistory.net.nz website. The feature was written by a professional historian who is writing a history of New Zealand Railways at the Ministry for Culture and Heritage.

I hope this is acceptable - please let me know if there is a problem with my adding this.

Jamie Mackay 09:43, 25 September 2006 (UTC)Reply

I like the new map,

but the old one;

usefully showed the sections that were and weren't electrified (its an interesting main line with its two systems separated by large section of diesel running) - not being a graphic artist can the excellent new one be edited to show this ??? Pickle

I provided a new diagram with different colors for different sections. I hope, this meet the desires. Greetings --Jörg Müller 14:00, 8 February 2007 (UTC)Reply

Absolutely marvellous, thanks Pickle 16:18, 8 February 2007 (UTC)Reply

Excellent work Jorg. --Lholden 20:55, 8 February 2007 (UTC)Reply

I've just put up the Route Map of the NIMT. If anyone has the Akl - Wgtn distances, their addition would be much appreciated. --Lholden 08:56, 17 June 2007 (UTC)Reply

If distances are indeed measured from Wellington to Auckland, shouldn't 0km be at Wellington? Or is this method of measurement peculiar to Wikipedia? 202.89.152.202 07:26, 11 November 2007 (UTC)Reply

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Makohine viaduct redirects here. I found this photo.of it but not sure if it's helpful. FloridaArmy (talk) 13:12, 4 August 2019 (UTC)Reply

Height & Length

Mangaweka 288 m or 945 ft 48 m or 157 ft

I suspect the height and length numbers need to be swapped. There's no way that old viaduct was 288 metres tall.

StuZealand (talk) 03:59, 20 November 2019 (UTC)Reply

This source says the viaduct was 288m long. Akld guy (talk) 00:22, 21 November 2019 (UTC) So does Pierre.^[1] Hugo999 (talk) 07:38, 13 April 2020 (UTC)Reply

The North Island Main Trunk goes through four regions and the railway station buildings are classed in the region categories for “buildings and structures” and for “rail transport in”. Several station articles do not have these categories or categories for station opened in (year) and if needed station closed in (year); will add them: Hugo999 (talk) 13:41, 9 April 2020 (UTC)Reply

• Wellington Region = Wellington to Otaki
• Manawatū-Whanganui Region = Manukau to Waimiha
• Waikato Region = Poro-O-Tarao to Tuakau
• Auckland Region = from Buckland to Auckland