Subscribe to RSSNew Arahura Bridge Opens - Separates Road & Rail
It’s been one of the largest and complex bridge projects on the New Zealand rail network in recent times.
And the new replacement South Island road - rail bridge, which opened today, has three excellent approaches going for it:
- It removes the railway line from vehicle traffic by separating road, rail and pedestrian/ cycle traffic. The new structure has two lanes with separate road and rail bridge spans next to each other. The new design will also have a combined footpath cycle way.
- For the first time in the southern hemisphere, a rubber panel system was used in the roundabout level crossings. This provides a rubber section which compresses and rebounds as trains travel over the crossing but at other times provides a flat crossing for motorists and cyclists.
- It has river guidebanks to protect the bridge and reduce flood and erosion risks, an issue in that region.
Those of us in the North, fixated on Auckland and Wellington’s metro improvements, have probably not been closely following the project, which is important not just for providing a single track railway, a two-lane road and a path for alkers and cyclists.
It’s a very big deal for the south, or at least the West Coast. The 220-metres-long $25 million Arahura road-rail bridge opening today was several months ahead of schedule. It’s a joint Kiwirail and NZTA project.
The Arahura Bridge is an essential link over the Arahura River for State Highway 6 and the Hokitika Branch Railway Line. It’s is the only direct route between Hokitika and Greymouth for road traffic.
NEW: Replacement after 120 years | NZTA
You can’t complain the area didn’t deserve it.
The present wooden, single-lane road-rail bridge has lasted for more than 120 years, providing that crucial link. The old bridge was built in 1887 and is 204m long and 3.2m wide.
OLD: Past its used by date | NZTA
Kiwirail Chief Executive Jim Quinn, said this wasn’t a typical rail bridge project. ”We’ve created a single-track railway, a two-lane road and a pedestrian / cycle way all on the same foundations.”
The old bridge was nearing the end of its life so securing this vital transport link for the future was important for the West Coast.
Around 3,500 vehicles use the bridge each day which meant one of the main requirements of this project was to keep State Highway 6 operational while the new bridge was built around it and construction was also staged to manage both the whitebait and dairy dry seasons.
The Arahura is an important whitebait fishing river. Where possible, bridge construction work was completed from the dry areas of the riverbed to minimise disturbance. During the whitebaiting season from September to November each year, major construction in the active watercourse stopped.
Normally, two to four trains a day travel to and from Westland Milk Products. However during the dairy dry season, which is three months each year, the use of the Hokitika Branch Railway Line is minimal.
The bridge contains 750 tonnes of reinforcing steel and 16 kilometres of post-tensioning strand, weighing 125 tonnes. 540 tonnes of structural steel was used in the rail bridge. 600 metres of new rail formation, ballast and sleepers were required. A total of 840 metres of rail was required for the length of the rail works and 730 new timber sleepers fitted on the rail bridge.
Rail was used to transport heavy construction materials to the site. All of the 99 road beams were made in a pre-cast factory in Rangiora then railed to the bridge site where they were lifted by crane directly onto the new piers. Steel elements of the rail bridge were manufactured in Napier before being railed to the site where they were assembled and installed.
Each pile is 25 metres long and driven 20 metres into the riverbed. The piers are 20 metres long and the spans 24 metres.
A single span from that original bridge has been retained to be used in a small heritage park nearby, which will be completed and opened around January.
About 100 mainly locals attended the ceremony. Heavy rain meant the transport minister couldn’t fly in.
5 Comments
Hey, your “new” bridge photo seems to also be that of the old bridge?
Yes didn’t look very modern did it Andrew! LOL Thanks for the wakeup!
Ummm, so the old historic bridge has been removed/demolished?
“A single span from that original bridge has been retained to be used in a small heritage park nearby” Grrrr. No historians consulted evidently.
And what is meant by:
“The old bridge was nearing the end of its life…”? Unable to be repaired * maintained at lower costs than replacing, or was older than the arbitrary 80 year life Ontrack tagged on bridges when they were created a few years ago?
I ask the awkward question again - what is the BCR for this low traffic bridge replacement? This project is another ‘we have to separate rail from road because it’s part of our rules’ mindlessness. A snip at a mere $25m. And people wonder why PT projects can’t get funded - that could have paid for the cycleway pver Auckland harbour bridge. Just saying.
Yes I agree 100% about replacing the State Highway 6 Arahura Bridge
with a more modern bridge that carries 4 different types of transport
which accomodates to all needs. I have also heard that the NZTA is
about to undertake a 15-year Single-Lane Bridge Replacement
Programme to do just that replace every one of the last 150 so single
lane bridges and structures in New Zealand. This is a must regardless
of those BCRs or blockages of progress because this is New Zealand not
an African, Asian or South American nation. I also think that these
people who complain about these road projects especially on the State
Highway Network do not want NZ to progress in terms of the economy,
socially, culturally, politically and the most important of all for this
nation. Bring these projects and programmes that benefit everyone.
Thanks very much
While Arahura has gotten all the PR, just up the road the Taramakau is still a single lane road rail, and there appears to be no real desire on anyone’s behalf to replace it.
The West Coast (south of hokitika)is resplendent with a large number of single lane bridges of considerable length. For NZTA to replace them all over the next 15 years, would probably be a $1 billion project.
I do know that TA are planning to spend $28 million to replace the Gates of Haast bridge in the next few years