Comments on: Guest Post: CBD rail tunnel concept

By: Dan Carter

Dan Carter — Thu, 15 Apr 2010 21:01:54 +0000

Great stuff!

By: Nick R

Nick R — Sun, 14 Mar 2010 22:35:25 +0000

Thanks Will, it is interesting to note that there has been no discussion or evaluation so far regarding the northern end of the tunnel… it has been assumed from the start that it would be connected to Britomart without and evaluation of any other options.

I guess it is easy to to get blinded by the mere possibility Auckland gets a rail tunnel at all, without thinking about whether the proposal is the most efficient or effective possibility.

By: Willuknight

Willuknight — Sun, 14 Mar 2010 11:05:16 +0000

This is facinating Nick. I certainly think that it needs close attention from the people responsible for finalizing the CBD rail project decide on the full scope of things.

By: Nick R

Nick R — Sat, 13 Mar 2010 05:31:03 +0000

Matt L, one problem with lengthening the trains is that Britomart cannot handle anything longer than a six car set. This is why building new tunnel platforms would be handy, you could build them all to accommodate eight car sets. Otherwise the new CBD tunnel stations will probably get built to the six-car maximum that Britomart has. No point having an eight car long platform at midtown if Britomart can only hold six.
I’ve assumed the trains would be run in six or eight car sets. While having longer trains does boost passenger carrying capacity it does nothing for train capacity… when it comes to having several lines running at quick headways you need to be able to get a lot of trains through, regardless of how long they are. I’m assuming here that it is desirable to have as frequent headways as possible. Obviously in the long run having the longest trains possible running and frequently as possible would provided the greatest capacity, that is what I have gone for here. My modification would allow twenty eight-car sets a hour each way in the tunnel. It looks like the current proposal would be limited to twelve to sixteen six-car sets an hour (once you account for terminating trains).

James, the ARC owns the Ports of Auckland so I’m sure they can manage some temporary arrangements. Most of that will be ‘party central’ before construction would start anyway. The port has indicated it’s intentions to vacate the finger wharves and consolidate at the container terminal. In terms of the political will and funding levels I’d put my money on what always happens in Auckland. A good project gets cut back to a shadow of its former self in order to save ten or twenty million bucks… then a few years later it is revealed to be inadequate and poor quality.

By: James B

James B — Sat, 13 Mar 2010 04:52:23 +0000

Yes I agree that your proposal could have a better cost benefit analysis. Unfortunately the political thinking may be skewed towards the less cost/less benefit side of the scales. Convincing me is easy, convincing Steven Joyce may not be quite as easy. Given the minister’s statements that he doesn’t think the whole project is necessary and you have a situation where trying to get him to open the purse strings wide enough to produce anything other than the cheapest option may be impossible.

One other point that I think would need to be cleared up is getting Ports of Auckland to open up the land on the other side of the red fence for the temporary road that you propose. Given the Port’s attitude to opening up that land before schedule it might be difficult to get them to come to the party.

By: Matt L

Matt L — Sat, 13 Mar 2010 04:36:09 +0000

There is also plenty of capacity in the tunnel if we were to lengthen our existing trains, 6 or 8 car sets would almost double out existing capacity without taking extra slots in the tunnel and most stations are already big enough to handle the 6 car sets with some already big enough for 8.

By: admin

admin — Sat, 13 Mar 2010 04:18:19 +0000

Nick, the flip-side to needing the additional capacity NOW is that we have more pressure to build it ASAP. If Joyce was a huge fan of this project we could have it completed by 2017 I reckon.

By: Nick R

Nick R — Sat, 13 Mar 2010 04:14:18 +0000

James: London’s main stations are on the periphery of the city, but they are also linked by one of the world’s most extensive metro systems. I might also add that London is currently planning tunnels to link its main overground stations via the central city. A better comparison might be the Australian systems which are the same hybrid suburban/metro that Auckland has. In each case like Sydney Central, Melbourne Southern Cross, Brisbane Roma St and Perth Station, the main terminus is in the CBD proper.

I don’t think is would come in cheaper than the current proposal but it might only be marginally more expensive when all is taken into account. While it does involve an extra station and 900m more tunnel, the extra tunnelling is a lot cheaper to do than section under the city and you save money by not having to build the tricky connection to the existing platforms.
You have brought up two good points. If it is simply a case of making things as cheap as possible my modification will obviously lose out. But if it is a case of building a stronger business case then mine might be superior. Remember it should allow twice as much new capacity on the rail system (or three times what we have now) for well less than twice the cost of the existing proposal. Like I’ve said above it might only add 15% cost to gain 100% more capacity plus a variety of other benefits. That might do wonders for the cost-benefit analysis and the business case…. which might make it more attractive to the Minister for Transport who seems to think in such terms.

Admin: That’s about as much as one could ask for however I would just point out two things. It *is* the original alignment, just an extension to it. All the work that had been done so far is still perfectly valid, I’m saying we take it a little bit further from where the current alignment stops. I’m not sure just how much consideration has been paid to the Britomart end so far to be honest, they have been focussing on just getting a preferred route through the CBD. Secondly, I would argue we need the extra capacity of the CBD or Quay St tunnel now, not in ten years or so.

By: admin

admin — Sat, 13 Mar 2010 03:52:10 +0000

Hmmm… I think my official position is going to be to promote the original alignment but to ensure it’s future proofed to link with a parallel line under Quay Street. That way we don’t risk the project as it’s currently proposed going ahead, but also we can get that extra capacity of the Quay Street tunnel/station when we need it.

By: James B

James B — Sat, 13 Mar 2010 03:51:34 +0000

Yes it probably is backwards, but I guess that’s what happens when you build a new station with no thought to the future needs of the network. I would point out that London’s main stations are all on the periphery of the city and they seem to do fine (except when you have to transit through from one station to another, but we don’t have to worry about that yet). I guess my concern is that, with a transport minister who is seemingly hostile to rail, Auckland has to do all that is practical to cut the cost and make this business case as strong as possible. If your proposal worked out cheaper and allowed for a stronger business case then that would be a far better idea, but it may be a case of having to put up with a less than ideal outcome. I also think that any proposal should take into account the idea put forward of having a boulevard along Quay Street and potentially undergrounding a section of road. Maybe we could do a two level cut and cover tunnel with the top level for road and the bottom level for rail. Although this might make the gradiant too steep up Albert Street.