Bridges are built for the long run. Some of them last hundreds of years. However, the old Mangere Bridge was built with concrete and steel in an unforgiving saltwater environment, and also had several run-ins with heavy freighter ships drifting into it during storm or accident.
And it hasn’t been exactly kept up well recently – you can see how it looks on the right. It would probably crumble if a truck drove over it today, which is why it is nice and empty – and pretty great for walkers, cyclists and people fishing.
So now it’s coming to the end of it’s life after a century of service – and NZTA (who for historical reasons still own it) is thinking about what should replace it.
NZTA have already announced a few key criteria they want the new bridge to have:
- be approximately six metres wide to accommodate pedestrians, cyclists and fishing activity
- have safe entry and exit points for cyclists and other users
- include sufficient lighting
- have clear sight lines so people can easily see what is around and in front of them as they cross the bridge
- be in the same general location as the current bridge
- be at a safe distance from the Port of Onehunga
- retain the old bridge’s navigational aids for boats
- allow for boat access underneath it.
With the Manukau Harbour area is becoming such a great place for cycling – with all the works done in recent years, and the new works still to come – do those criteria sound good? Mostly yes – though we have a few comments we’d like to raise. Here are our initial thoughts:
- Six metres sounds pretty good for a bridge without motor vehicles. But the fishermen are switching sides depending on tide AND their rods are long and have barbed hooks… how will the design ensure that there will always be a safe and wide enough (3m+) path left for walking and cycling? The current bridge is 15m wide after all.
- Maybe separate the two uses physically? But in what form – “internal” railings separating the two parts of the bridge might be a bit harsh? A “staggered” bridge with fishing platforms hanging off each side, a bit lower down? Or simply make it wider than 6m?
- What about mopeds? Sure, they are likely to be forbidden to use it (if it becomes signed as a shared path) – but we know in reality, they will. Again, this may require more width.
- How will the boat access work – will the bridge span be high enough, or will it be a lifting section? If not a lifting section, how steep will the gradients be – will it be a gentle rise over the whole length, or a sudden “hump” in the middle (not so good for cyclists…)?
- What surface is intended – with such a great length of bridge, a boardwalk type flooring should preferably be avoided in favour of a smooth riding surface.
- [Update] Lighting – hopefully, the new bridge will provide lights so one feels a bit safer at night there?
So sound out with your own thoughs in the comments field below, and also provide feedback directly to NZTA (online form).