A Ngaio Gorge cycleway

30 01 2011

This post is a thought for the future, being a little ahead of the curve. After we’ve built the Great Harbour Way and we’ve built the bike lanes across the Cake Tin concourse, and Wellington is a city of trams and ferries and bicycles we might like to consider developing this idea.

At the moment Trelissick Park is for pedestrians only, and is a nice place for a hike, so close to the city, and yet quite wild in places. I’m not encouraging anyone to cycle up there at the moment.

The idea is to build a quality shared cycle and pedestrian way through Trelissick Park, up the Ngaio Gorge, ending the cycle path in the bottom of the gorge beneath Crofton Downs station. Crofton Downs station would then have the train station for the Johnsonville trains, an elevator (like the one in Durie Hill in Whanganui) from the bottom of the gorge to the station level, plus there’d be an aerial gondola from Trelissick Avenue in Ngaio (giving people at the southern end of Kenya Street bit of Ngaio, easier access to the Johnsonville Line). Crofton Downs was put forward as one of the TODs for a redevelopment of the railway station area, and this could be a part of that. The elevator, the station and the station end of the aerial gondola could be manned by as few as one or two people if sufficiently automated.

On this map the dashed red line is the current Northern Walkway, the green line is an aerial gondola. The red circle is the elevator, and the red line is the path of the bikeway. And yes the red line through the hill is a tunnel. This plan is nothing if not ambitious. More on the tunnel below:

So if you’re on a bicycle you could ride up the waterfront, over the Cake Tin concourse, up the cycle path through the area currently all rail yards, to behind the Interislander terminal then up the waterfront Great Harbour Way for a short distance, then ride over the railway lines around Kaiwharawhara and up the Ngaio Gorge, all the way to Crofton Downs, and all the way from Oriental Bay without ever once having to ride your bike on a road, or even have an at grade road crossing. Then at Crofton Downs you put your bike in an elevator and ride it up to the station and then continue riding on cycle lanes on Churchill Drive and Waikowhai Street, or you put the bike in a gondola cabin and fly over the gorge to Ngaio and ride from there, or you put your bike on the train and ride to Johnsonville, or it was a bike share bike so you put it into a rack and catch the train back to Wellington.

The Kaiwharawhara end is a bit of a shambles, but that could be fixed with a rebuild of the Kaiwharawhara station environs, and linking the existing tracks in Trelissick Park which run past the ruins of the magazine buildings with the Great Harbour Way, with some combination of going over and under Hutt Road, the motorway and the railways, following the creek, School Road and past the oil tanks.

In Trelissick Park at it’s eastern end the existing path is quite wide:

The track remains flat and gets a little narrower. There seems to be at least two generations of buried sewers buried under and beside the existing tracks. I’d widen and flatten a couple bits of it, but where there is still room I’d build a paved (and lighted) cycle path. Looking westwards (as if riding towards Crofton Downs) the creek is on the left, some of those photos are looking backwards:

where the trail has started to thin out, where it could be widened a little, and where the sewer pipes are under the trail:

And here is were I’d start the tunnel (just past the gated entrance to the sewer tunnel):

So a tunnel? I must be a crazy. Firstly there are already other tunnels in the park. There are a couple of sewer tunnels, and there is a tunnel that carries the Kaiwharawhara Stream under the Johnsonville Line. The Trelissick Park Group (a friends group of the park) even suggest making that tunnel open to pedestrians. I went down and had a look. From the outside it looks unpromising:

But with a stoop, and a torch it is kind of walkable, albeit not that comfortable. My general impression was that it isn’t a good idea to send people walking through the tunnel. I ended up with a cut head, as so too would a lot of other people. Here’s the inside.

The cycleway tunnel would only have to be 300 metres long which is only half the length of the Summit Tunnel on the Rimutaka Rail Trail. (I know the Summit Tunnel was built for trains, not cyclists, and building a tunnel for cyclists may be nearly a world first, but if it is in the public interest then why not? The 3 other nearby tunnels show geotechnically it wouldn’t be that difficult). West of the cycleway tunnel then a couple of the small wooden bridges over the Korimako Stream may need some realignment.

This photo shows the small hill where the Crofton Downs elevator would go. From near the grassed area at the bottom of the gorge to the rail line, which runs across the photo at the height of the white roofed hardware store. The existing station is the little red roofed building. There are walking tracks to get up the hill, but they’re not suitable for bikes.

And this is a photo showing where the aerial gondola station would go on the Trelissick Ave side. It is a straight line route only about 400 metres long across the gorge, which would angle down to the station just to the right of the white roofed hardware store again:

Well it’s a better view of the future than widening the motorways and not fixing up the areas they run through.

Also after a comment I received, I’d like to point out that  the cycleway as envisioned from Kaiwharawhara to the bottom of the elevator at Crofton Downs would be near enough to flat  for the whole of it’s distance. The tunnel is necessary, as the gorge itself where the tunnel bypasses it, is narrow, no place for a bike, and quite picturesque.




3 responses

4 04 2011
Micro-ferries for Porirua Harbour « Wellington Region Cycleways

[…] 6 trains an hour instead of the current 2*. It’s a bit like the aerial gondola suggested on this post between Ngaio and Churton Park. It puts more people within walking distance of a part of the linked up network, and keeps people […]

3 12 2011
Te Araroa Trail opening « Wellington Region Cycleways

[…] talked about keeping on going over Tinakori Hill, Ngaio Gorge, over Mt Kaukau and into Johnsonville and then we shortened it to just Crofton Downs station, then […]

9 07 2012
Please help the NZTA with understanding Petone to Ngauranga « Wellington Region Cycleways

[…] It’d also be a mighty fine idea to link it to the Ngaio Gorge cycleway. […]

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