Truckers at risk crossing Mt Ruapehu bridge with 'severe' defects

An engineer's report found the bridge has broken running boards and broken cross beams that rate as "severe" defects.
An engineer's report found the bridge has broken running boards and broken cross beams that rate as "severe" defects. Photo credit: Supplied

By Phil Pennington of RNZ

A century-old wooden bridge full of holes that carries masses of the country's potatoes and carrots is jeopardising truckers' safety and farmers' livelihoods.

But Government funding changes make it less certain the local council can get the bridge, on a back road on the slopes of Mt Ruapehu, replaced.

Between a 10th and one-fifth of the washed carrots and potatoes used in the North Island come across the one-lane timber Mangateitei rail overbridge near Ohakune.

There is no other public road out from the farms.

But a new engineering report has surprised and dismayed the Ruapehu District Council.

It rates the bridge's load-carrying ability as a "four" - this means it has "severe" defects including cracks and decay, and it is "peppered with core holes".

None of the repairs recommended in a 2019 investigation were done because the bridge needed replacement, not just repair, the consulting engineer's report shows.

Alarmed, the council has cut the allowable weight to 60 percent of what it should be for a Class 1 bridge.

That's enough to bear the weight of Dave Hammond's truck - so long as he puts none of his contractor equipment on the back.

"They've taken 75 percent of my payload away, to come across legally," Hammond said.

"So I can only take about three tonne on my truck where I can take about 12. It renders the bridge useless to us. We can't unload gravel, for instance, on one side and reload it on the other."

He is among local contractors and growers who have made an urgent appeal to the district council to not force them to risk their safety, or be criminalised.

Council chief executive Clive Manley said: "You cannot get produce across safely anymore."

The engineers suggested trucks had damaged the 113-year-old, 17.4 metre-long bridge.

Mayor Don Cameron said the problem was indicative of a "bow-wave of ageing bridge stock" facing rural councils.

'We're having to break the law'

Hammond had not changed what he was doing since weight restrictions dropped to 60 percent.

"We're having to break the law, exceeding the bridge limits."

The council is now installing cameras that can read number plates to spot loaded trucks at this bridge and another old bridge on the edge of Ohakune, at Ruapehu Rd, that is not on a vital agricultural route.

Scott Young's family company grows most of their vegetables on the rich volcanic soils up Mangateitei Road.

They cart up to 150 tonnes a day across the bridge for four months of the year.

"We have a dangerous bridge here that's jeopardising lives and livelihoods that NZTA hasn't wanted to replace - or hasn't actually got funding to replace," Young said.

The council was hoping that due to the threat the weight restrictions had to "disrupt the supply of produce nationwide, it will be seen as a special case and treated with urgency", Cameron said in a statement.

But Ruapehu, like councils everywhere, faces a lack of ways and means to readily replace even dangerous bridges.

Ruapehu Rd bridge.
Ruapehu Rd bridge. Photo credit: Supplied

Local bridges no longer have their own funding category at the New Zealand Transport Agency - Waka Kotahi, but must jostle with other demands for scarce maintenance dollars, an ironic upshot of the Labour government prioritising regional roading.

Waka Kotahi was expected to decide in June if it would put up its share - 75 percent - of the multimillion-dollar bridge costs.

However, Manley feared it might take until August - and even then, it would take a long time to build a replacement.

"At the moment there isn't an alternative," Manley said.

"We will have to do it ... but it will be a huge burden on our community if we don't get government subsidies."

Waka Kotahi "has not said no, they just haven't been able to say yes" and that was partly down to changes in how local bridges were funded, he said.

"It is more uncertain."

Cameron said funding criteria had prevented them unlocking the co-investment subsidy "despite the [two] bridges now being functionally useless to the freight movement critical to our agricultural economy".

Cameras versus collapse

As for policing the bridge, Manley said cameras were not primarily to sting truckies.

"The prosecution is irrelevant. It's the safety that's paramount.

"Having the bridge collapsing, there's electrified rail underneath - we do not want anyone to be hurt or harmed."

The engineers' report found parts of the bridge superstructure were "between deteriorating and seriously deteriorating".

One crack was a metre long and 18mm deep.

The inspection was an intensive one done on bridges every six years; a less detailed check is made every two years.

Young said it was dangerous, but people would keep using the bridge as it was their livelihoods at stake.

His family had a makeshift alternative - a $100,000 private road they put in a year ago across their farm to clear a forestry block, because logging trucks were too heavy for the bridge.

But it took longer to drive, and though the council had broached the idea of others using that road, that was a no-go for security reasons and because rates and road-user charges were in place to provide local roading, Young said.

"There is a lot of food that comes off that rail bridge. You'd really want to fund main artery routes for that. I don't know why they wouldn't want to be all for changing a rail bridge to supply that produce and meat."

'341 aged bridges'

NZTA said it was talking with the government about getting more money though revenue overall was up - in part to address the three-year roading plans that councils nationwide were now drawing up.

"Waka Kotahi is aware of the issues concerning Mangateitei Bridge and we are working closely with the Ruapehu District Council," its director of regional relationships Emma Speight said in a statement.

It had been telling councils for over a year that there were "significant funding constraints" for the 2021-24 National Land Transport Plan, she said.

Council bids for funding were a fifth higher than for the previous three-year plan.

Cameron said the national situation was grim.

"In our case, we have a significant stock of 341 aged bridges including large culverts, the majority of which were built around 100 years ago, across a 350km road network of which two thirds is unsealed."

Using debt only to fund bridge replacements such as Mangateitei was not on, he said.

Young and Hammond questioned if local and central government knew how to run a proper maintenance plan and depreciate assets given there had been talk for years that the old bridge had to go.

A district councillor known of by Young had spoken 10 years ago of plans to replace the bridge.

"We still haven't seen anything," he said.

The council said it had already set aside $1.2 million for the two bridges.

"We do rate for depreciation at a level that is considered appropriate which is audited by Audit NZ, however, this only covers repairs and maintenance and our 25 percent local share with Waka Kotahi," the council said.

The locals said the best solution would be to put in a level crossing 100 metres south of the bridge, on the edge of Rangataua settlement.

But KiwiRail had safety rules that meant in order to add a level crossing it must close another one somewhere else. KiwiRail has been approached for comment.

The engineers advised against trying to repair the bridge, as it was made of old timbers and that would require protecting the piers and raising the road at least another metre to meet rail clearances.

And Ruapehu District Council faces other hurdles.

"Without further government assistance, our debt level over the 10 years of our new Long-Term Plan is already projected to grow to an uncomfortable $100m, driven mostly by the mandated water quality reforms," Cameron said.