Restoring six SH1 bridges damaged in the Kaikoura quake involved a very complex heavy haulage programme to get over 100 concrete beams from the North Island to the South in a few short months. By Mary Searle Bell.
IN LATE 2016, a 7.8 magnitude earthquake rocked Kaikoura, devastating the landscape. State Highway 1 between Seddon and Cheviot was badly damaged – the NZ Transport Agency estimated that close to one million cubic metres of rock and debris fell onto the road and adjacent railway line. In particular, the highway north of Kaikoura required months of work to repair.
However, on December 14, 2017, one year, one month and one day after the earthquake, following a tremendous effort by the North Canterbury Transport Infrastructure Recovery (NCTIR) alliance partners, the road was reopened.
HEB Construction is part of the NCTIR alliance and has been responsible for rebuilding and repairing a number of bridges damaged in the quake. These included the seven-span Irongate Bridge, north of Mangamaunu, six debris flow bridges (three road and three rail), Bridge 908 south of Ward, and the 480-metre rail bridge across the Clarence River.
Construction of the new bridges required 144 concrete bridge beams. Because of the time and supply constraints of the project, the majority of these beams were manufactured in the North Island – about 80 percent in Rotorua, more in Hastings and at HEB’s plant in Mount Maunganui, and just 11 in Christchurch.
“Only a few places could manufacture beams of this size in time,” says haulage project coordinator, Darryl Holden of HEB Construction Heavy Haulage. “The plan was to get the beams to a storage site near the project and have them ready and waiting for the bridge builds.”
The beams all had the same dimensions, and were 21.95 metres long. Most weighed 32 tonnes, however the outer beams (about 10 percent of the total) were far heavier, says Darryl, weighing 39 tonnes each – these ones were manufactured in Hastings.
The timeframe for delivery was August to November 2017.
“It was a logistical nightmare getting all 144 beams down there,” says Darryl. “First, we had to analyse the road to work out how we were going to get them to site, then we had to liaise with the NZTA regarding having so many 30-metre-long loads on the road between August and November – we knew we would be flooding the road with heavy gear, and this was a road already under pressure because of the closure of State Highway 1.”
From the North Island, the beams travelled across to Picton then down the alternate Picton-to-Christchurch highway via the Lewis Pass before heading north up the inland road to Kaikoura. The option of travelling north from Kaipara was ruled out – the loads couldn’t go through the tunnels on this route as the containers holding the slips back meant the beams couldn’t get around the corners.
“We had to do a feasibility study, and look at all the bridges on the route, including a number of Bailey bridges. We also had to consider ferrying the loads across the Cook Strait – we didn’t want to have too many beams on a ferry, nor overload the road from Picton.
“In addition, Wellington Harbour had also suffered quake damage, so a few fences had to be realigned so the beams could be loaded onto the ferries.
“Then we had to chat to our concrete precast suppliers as they could manufacture the beams faster than we could load and take them away, but they didn’t have room to store them for us.”
Darryl says they created a load-out programme, which entailed the beams being placed in the yards in a specific order so the right ones could be accessed at the right time.
“We had limited resources so the only way we could get all the beams to site on time was by engaging subcontractors,” says Darryl.
In addition to the HEB heavy haulage crew, teams from five different haulage firms were subcontracted to move beams. NZ Heavy Haulage Association chief executive Jonathan Bhana-Thomson describes it as a great piece of collaboration.
“Six individual members of the association were involved in sharing the transport of these beams,” he says. “I don’t think there’s been a project quite like this before in the history of the organisation.”
Regardless of who was doing the move, all the loads were configured the same. They each had a truck on the front and a jinker behind. The tight corners and the bridges going into Kaikoura ruled out the use of trombone trailers.
Due to the nature of the traffic on the road from Picton to Kaikoura (tourist traffic in particular), the loads were escorted by three pilot vehicles over this stretch.
The first beam started its journey to Kaikoura on August 22, with the last beam arriving from the North Island on November 8. HEB then started feeding the bridge sites from the laydown site.
“We were able to use trombone trailers for the lighter beams as the corners weren’t so bad,” says Darryl. “We had two HEB units on it, and later added a third.”
The final beam was delivered on December 5, and Darryl was finally able to catch his breath.
“I celebrated when we finished,” he says with a laugh. “We couldn’t have done it without the support of all our subcontractors. And you have to remember that they all had previous projects booked that had to be accommodated – their normal work had to continue; Kaikoura had to be squeezed on top.”
These additional jobs had to also be factored into this load-out programme, further complicating the already complex schedule.
“We had a weekly programme that detailed exactly what was happening. We were always within two to three hours of this,” says Darryl. “The hiccups happened when snow or an accident occurred, then a beam would catch up with the one in front of it, so we’d have to delay the second truck to ease the load on the road.”
The police and NCTIR constantly monitored the transport project, and of the 144 beams shifted, only one – the second to last – garnered a negative comment from a member of the public, who said the load should have pulled over earlier to let their vehicle pass.
But if that is the only piece of negativity in this logistically complex project, then Darryl, the HEB team and their heavy haulage subbies can be very pleased with themselves.
This article was first published in Contractor‘s March issue.