Can we put cyclists through Lyttelton Tunnel?

A post currently doing the rounds on Facebook is once again raising the possibility of getting bikes through the Lyttelton Road Tunnel under their own steam. At present, the 52-year-old tunnel only allows bikes that are attached to the racks of the buses that go through. On the very odd occasion, people walking and cycling have been allowed through, most recently to celebrate the 50th anniversary of the tunnel in 2014 – and what a demand there was for that…

2014: A sea of humanity enjoys the Tunnel sans cars

The latest graphic proposes that the ventilation shaft of the tunnel (above the roadway) be re-purposed to also allow people to walk and ride through. This large space (~12 foot high in the middle) is split in two longitudinally; one side pumps fresh air into the tunnel and one side extracts vehicle emissions. The idea of course is to allow people to access the former section where the fresh air is, by creating path links up to each end.

The grand plan: Bike access through the tunnel

I’m not sure who came up with the $1.5 million pricetag but, in the current scheme of things with hundreds of millions being spent on cycleways in Christchurch and around the country, it’s not a particularly outrageous cost (particularly in the context of >$400 million being spent on two motorways near Christchurch this week…).

This is not the first time that this proposal has been considered; in fact 15 years ago, Spokes Canterbury were engaged in discussions with (then) highway operator Transit NZ about options for cycle access. So is it feasible? There are a few things to consider:

  • Halfway along the ventilation shafts are bulkhead doors that allow the fans to work most effectively. So any proposal would have to come up with some way of allowing people through these doors, presumably while still maintaining an effective ventilation system.
  • I could imagine that the ventilation system would be pumping air fairly strongly into the tunnel. Depending on which way you were travelling, that could mean a strong tailwind or headwind. Perhaps not so much of an issue for the Lyttelton half of the tunnel, with the 3% gradient of the tunnel counteracting the opposing air pressure. But it could be a bit trickier in the Heathcote half if you have an uphill gradient and a headwind…
  • In these days of heightened health & safety awareness, an enclosed space like a ventilation shaft introduces new risks that the tunnel owners (NZ Transport Agency) would have to be happy to deal with. I see that the above proposal is suggesting regular alarm buttons and security cameras, but even that might not be enough to please the powers-that-be.

Interestingly, when Spokes looked at it, they acknowledged some of the inherent difficulties with a ventilation shaft route, and suggested using a shuttle vehicle instead – the tunnel operators have to maintain service vehicles for things like escorting large vehicles through the tunnel, so it wouldn’t seem to be a big stretch to fit one with seats and bike racks for an on-demand service. Mind you, this was 15 years ago, when the prospect of the state highway agency doing much for cycling (let alone spending $1.5m on a cycle project) was unheard of – times certainly have changed…

Lyttelton Tunnel under construction, showing ventilation shafts above

It’s an interesting discussion; I’m not sure that the fundamental technical issues can be addressed, but that’s something that others with more expertise than me in this area would need to consider. I guess an interesting parallel is with Auckland’s Harbour Bridge walk/cycle crossing (SkyPath), where various technical and financial objections to it by NZTA have been progressively dealt with by the very persistent campaign group – and it looks like it is almost over the line now. Will Lyttelton Tunnel be Christchurch’s SkyPath?

What do you think about trying to get bikes through Lyttelton Tunnel?

7 thoughts on “Can we put cyclists through Lyttelton Tunnel?”

  1. Hi there. This is something I was keen on about 4 years ago.
    I took the idea to ministry of Awesome, and they liked it. With their help we were able to arrange a walk through the shaft with the tunnel manager.
    He is not keen on the idea, and I must admit, after having a good look around I agreed with him.
    There are a few technical difficulties – not insurmountable, but tricky. There is a large water main running down the side of the shaft – this supplies Lyttelton. When entering the tunnel from the side this will need to be crossed, and the shape of the tunnel makes this really difficult.
    Once in the tunnel it’s good, plenty of room, but then there are other issues. The bulkhead halfway down I don’t think is much of a problem – it just needs a double door airlock type system so there is no loss of pressure. This could easily be done with auto doors.
    I think the main killer for me was the problem with the fumes. If there is a fire the shaft could possibly fill with smoke, or just get really hot. You wouldn’t want to be in there if that happened.
    The trucks passing under are almost scraping the ceiling, and the shaft floor shakes and shudders as they go by. It would be pretty scary and confined for some people.
    Over all I thought that for the expense to get it all working it wouldn’t be worth it for the amount of people who are happy to ride through such a long tunnel. The routes over the top are much nicer, and you can get the bus through if necessary.
    I did think it would be worth investigating an automatic shuttle type thing that maybe just has a docking station at either end, and can be called on demand. It could be unmanned.
    Hope these comments are useful.
    cheers
    Roger

    1. But the main Evans Pass route over the top will not reopen for at least another year. Options are to go round and over Dyers, much longer and tougher (especially when starting in Sumner), up & over Bridal Path (brutally steep both ways) take bike through on bus (uncertain delays, & definite cost), just drive it (easy but not environmentally friendly, & highest cost). I would use the through-tunnel option.

    2. Hi Roger,
      I’m keen to discuss this with you at some point. There is a significant amount of interest either side of the tunnel amongst my friends. I have read your points and keen to see if there are ways to overcome these challanges. Regards Andrew

  2. The Lyttelton Tunnel is an example of shortsighted transport infrastructure built with solely motor vehicles in mind. It would have been sensible to build the tunnel with space for cycleways and footpaths, because it is much more costly and difficult to come back and add cycleways and footpaths at a later date.

    The same sort of thing is especially an issue in the United States where many suburbs were built with no footpaths and it would require more taxpayer funding to come back and install footpaths on these streets, and because of the car oriented transport infrastructure it is often nearly impossible to actually get anywhere without a car anyway. This really highlights the importance of well thought out urban planning in our cities, and actually ensuring that every street in every city that we build has good provision for every mode of transport, not just cars.

  3. Hi,
    I live in Sumner and work in Lyttelton. I currently ride to/ from work via Evans Pass, Summit Road and Bridle Path. Great work out. I’ve discussed a human powered access via Lyttelton tunnel with residents on either side and all very supportive. I understand this has been revisited about 4 years ago and think i appreciate there are challenges to make this happen. I’d like to investigate this further. Any direction to point me in? Regards Andrew

Leave a Reply

Your email address will not be published. Required fields are marked *