With the Upper North Island Supply Chain Study (UNISCS) starting to show results, I thought it would be a good time to examine some of the possible implications; constraints and opportunities, for the Auckland rail network, of an increased freight task to and from Northland.
This is not a post discussing the merits of any such move but rather a look at a possible resultant scenario for the city’s rail network. I am writing this in advance of the completion of the Study’s work so it’s pretty broad brush.
Any move of port operations at scale to NorthPort will require a substantial upgrade to rail infrastructure there and in Auckland. Only rail can serve a port at such distance efficiently to its main markets.
The general plan is to complete the rail line to port connection: The Marsden Link. And the North Auckland Line (NAL) itself needs a major upgrade as it’s in a very poor state, with many undersized tunnels, rickety bridges, and sections of wobbly track. Then an inland port somewhere on the outskirts of North Western Auckland is planned, where freight to and from the port can be marshalled, some distributed directly from there by road to West Auckland and North Shore destinations. The remaining freight is then to be trained through the Auckland network at night, when Metro services are not using it, to distribution centres in South Auckland and the rest of the North Island. The addition of a rail fed inland port in the North West enables logistics companies to serve their West and North Shore markets without having to drive through the congested isthmus. A critical pinch point for all transport services.
The key here will be to time the transfer of port tasks north with not only the necessary port infrastructure but also the required rail network improvements:
- Marsden Link
- NAL upgrade
- NW Depot
There is both the ability to stage these investments, as well as some quite serious limits to that. Certainly building the Marsden Link would have the immediate effect of enabling Northland bulk goods like logs and milk powder to be trained northwards to NorthPort instead of south through Auckland to the port there or Tauranga for export, as they do currently. So it is likely that this connection alone may enable more efficient and more frequent ship visits to NorthPort, but without improvements to NAL even this may be of only marginal value. And there are no doubt effective ways to stage the NAL upgrade overtime, but, any move of major tasks currently undertaken at Ports of Auckland, especially the container trade, would require all three investments along with considerable investment at NorthPort itself.
There may be opportunities to shift individual sectors north, say like the car trade, but any whole sector will require the depot and fairly serious work on the NAL. Presumably we will see more detailed discussion of this when the indicative business case drops soon.
In order for a substantial increase in night trains through the existing Auckland Network to be socially acceptable, and to further increase environmental benefits, it seems likely that electrification will need to be extended north to the depot (though this is probably dependent on further electrification projects, especially closing the gap between Auckland and Hamilton). Happily this also means that extension of Metro services to Waitakere, Kumeu/Huapai, even Waimauku, depending on development, would be able to follow this work too. Perhaps this would require double tracking as well? So possibly we can add:
- Double tracking and electrifying from Swanson to Kumeu and/or new depot, plus resultant station works.
Under this scenario, a fair bit of work will also be required on the rest of the Auckland Network to accommodate these growing freight volumes from Northland and Bay of Plenty/Waikato. Particularly in the context of the coming boom in Auckland Metro services; ridership is expected to double fairly quickly on the back of major investments in the network, particularly the CRL (and bus network improvements; as these systems are integrated). Train paths will also need to be found for reviving Intercity services. Already there is a growing need for additional track especially on the main trunk between Wiri and Westfield, as this is also the busiest Metro path and the necessary Intercity one; separating freight and Metro paths is an ideal way to increase network capacity and reliability for both. At least four tracks will be needed here, with six at important stations like Ōtāhuhu and Puhinui. Largely there is space for this along the NIMT spine. Some of these are in planning now, including electrification to at least Pukekohe.
At some point (and depending on how big NorthPort gets) the volume of freight traffic north will outgrow overnighting through Auckland. Then there is the much more difficult problem of expanding the line through west Auckland. There has long been a designation between the Westfield Junction and the Western Line (NAL) next to the Mt Albert Pak n Save, called the Avondale-Southdown Line (ASL), which was designed to create a bypass around the Newmarket junction for west-south trains. However any detailed look at this ancient relic shows that it is all but unworkable as a surface line, would be very expensive, and critically, doesn’t solve the problem.
A key difficulty with this route is that wiggly central section that winds through dense suburbia crossing many streets (18 by my count on this section alone) and houses, before joining a much more straightforward section alongside SH20. But worse than that is the fact that it rejoins the existing line still east of both the troublesome level-crossing plagued Avondale incline, and worse still, the two track only New Lynn trench. So while it does bypass Newmarket and the very inner section of the Western Line, it doesn’t bypass enough.
Never fear. There is a much more elegant solution that avoids all these issues and probably costs no more that this suboptimal historic work-round: A dedicated freight tunnel direct from the Onehunga marshalling yards to some point west of the New Lynn trench (I favour a point west of the West Coast Rd overbridge). It avoids the steep grades, built up suburbia, and the worst of the western line; so ditch the poor ASL and go for the Mega Freight Tunnel:
12km of curiously flat, hill and human avoiding, rail tunnel. Yes at ~12km it would be 50% as long again as our longest current tunnel, Kaimai, interestingly the very thing that makes Ports of Tauranga competitive in the Auckland market. If electric and freight only it can be bored and run relatively cost effectively. Tunnelling, while never cheap, is not the most expensive part of underground rail networks; stations and passenger systems are much more complex than actual tunnel boring. So by dedicating this to freight only it can be a considerably more straightforward build. And as the western line right of way is much less constricted west of New Lynn (or more accurately west of Fruitvale Station) even a single track tunnel combined with a new third west from its portal to Henderson or Swanson would provide an entirely grade separate dedicated freight railway through West Auckland, connecting directly to the Onehunga yards, and so on south. Completing a 24 hour available dedicated and direct freight railway linking the North Island Main Trunk and the North Auckland Line free from competition with Auckland Metro services. If all major freight is moved from the current downtown port, leaving cruise ships and local vessels only, then Kiwi Rail’s freight business would have little need to use the current central city sections of the rail network (though that would still be available when necessary). This would enable current lines to be used entirely by Metro and other passenger services, like Kiwi Rail’s returning Intercity programme:
Such an outcome would enable all sorts of improvements; especially the space to meet the rapid Metro service growth post CRL, increased ‘Metroisation’ of urban rail services; higher frequency, longer span, and even automation. It would also free up train slots for increasing Intercity services, and of course enable a more efficient and higher capacity freight route (currently KR run 22 trains day through the single track Kaimai tunnel).
All of this would be very expensive, but then so are the alternatives. At some point separating urban passenger and freight services will be needed in Auckland if both are to continue to grow. And whether that is done by duplicating existing paths or building whole new routes is going to need to be evaluated and considered. Already we are doing both; adding additional track to existing paths, and whole new task specific routes (eg CRL). Dedicated freight lines are nothing new either.
Below is a description of the Landside Freight Task for Ports of Auckland from the Port Future Study:
If major port operations stay at downtown Auckland then the Eastern Line will need at least tripling, which while relatively straightforward between Ōtāhuhu and Glen Innes would be punishing from there down to the port, if possible at all across Hobson Bay (consenting risk).
Having our biggest and fastest growing city astride the narrowest pinch point in the nation’s physical geography is going to increasingly require innovative transport solutions. Shifting the port from downtown Auckland will free up current city transport systems- road and rail- for other tasks, whereas leaving it there will require very expensive and disruptive expansions of motorways and railways through the dense centre of our biggest city, in order to accommodate increased freight arriving downtown.
If some considerable part of Auckland’s port operations is to head north via the rail network, the necessary rail infrastructure investments look like an opportunity to sort out some of the historical complications in the interlined Auckland rail network; to devolve parts of it into a super efficient two track Metro, and others into a dedicated freight railway. To the advantage of both systems.