Light at the end of the tunnel

It took 20 years to hack a railway track through the tortuous Manawatu Gorge in the late 1800s, and more than a century later a major upgrade is allowing the same line to carry the modern hi-cube containers that are boosting rail transport’s competitiveness with road.   BY HUGH DE LACY

Wellington-based HRS Construction will this month complete the daylighting of three tunnels at the Woodville end of the gorge so that bigger, 2.9 metre high freight containers can be used on the Wellington-Gisborne line. It’s part of the plan by the government’s line owner OnTrack, recently subsumed into the state-owned Kiwi Rail company, to boost rail’s share of the national transport burden.

The three tunnels being eliminated under HRS’ $3.1 million contract are hard up against State Highway 3, so cutting back the cliffs and opening the tunnels to daylight has involved juggling the work around the necessity to keep both road and rail open to traffic. The project, which involves removing 240,000 cubic metres of rock and spoil, began in early May, and HRS is on schedule to complete it early this month.

The Manawatu Gorge has always presented a challenge to traffic moving between the western and eastern sides of the North Island. The first road was punched through on the south side of the river by contractors Henry McNeil and Clark Dunn in the 1870s. Dunn had the contract to cut the road, while McNeill built the bridge over the river at the Woodville end that brings the road alongside the railway.

The road was a single lane for decades, gradually being opened up to two-way traffic largely in the wake of the clearance of the frequent slips that blocked it.

Building the railway on the north side of the gorge proved no less of a challenge. It was first surveyed in 1871 but work didn’t start until 1886. The project bankrupted the original contractor and wasn’t completed until 1891.

While the road on the other side of the river was gradually widened and improved, the railway line through the gorge remained largely unchanged until earlier this decade when the floors on two long tunnels in the middle of the gorge were lowered to accommodate bigger containers. Lowering the floors was not an option in dealing with the three eastern-end tunnels because they were so close to the road.

In announcing the project earlier this year, OnTrack chief executive William Peet said that the tight Manawatu Gorge tunnels had “long been a block to the movement of goods by rail across the North Island. With the elimination of these three tunnels the last major impediment will be removed. It will be a significant step towards making rail more competitive for the movement of containerised goods.”

The three tunnels being daylighted in the latest work are all relatively short: Tunnel Three and Tunnel Four are each 45 metres long and just 40 metres apart, while Tunnel Five is 60 metres long and 600 metres up the track towards Woodville.

The project originally envisaged the removal of 160,000 cubic metres of spoil, but by the time it’s completed the total will be half that again. The cliff into which the tunnels were originally carved is hard limestone rock, and HRS’ job was to cut them back in a series of 15 metre high steps. The spoil from Tunnels Three and Four went to a crushing plant 300 metres away, while that from Tunnel Five is being used to fill an old quarry hole in the hill above.  

HRS project manager Peter Tangney told Contractor the main ripping work was accomplished with a D9 Caterpillar bulldozer, backed up by a D6, while two 20 tonne and one 30 tonne  Hitachi diggers loaded the spoil onto four 25 tonne trucks for dumping.

Almost from the start of the project Tangney said the road had to be closed for up to 10 minutes every couple of hours, and the line cleared regularly to allow the scheduled rail services through. Huge limestone rocks had to be broken up, and soft spots in the cliff required more spoil to be removed than originally estimated.

HRS was well into the project when, in August, the company announced it had been taken over by Downer EDI Works, though its new owners will continue to operate it under its existing title. What became HRS was started in 1996 by Tangney and a mate, John Forde, though Forde later quit the business.

They started out with eight diggers doing earthmoving and excavation contracts, much of it for building companies and on farms. Six years ago Tangney teamed up with the then Wellington manager for Porter Hire, Terry McGee to form HRS with an eye to targeting rail contracts. Tangney manages the civil construction work and McGee the railways contracts.

The rail network, lines and all, were still privately owned at the time Tangney and McGee formed HRS, but they could see the Government’s mounting frustration with successive American and Australian owners who seemed to show no commitment to the capital development of services to allow rail to compete more effectively against road transport.

By the time the Government bought back first the tracks, and this year the rolling stock and business, HRS had built its rail maintenance work in the lower North Island up to about half its total output, and was operating no fewer than 10 diggers – all Hitachi – on railway wheels. With the Government now poised to spend hundreds of millions of dollars on upgrading the rail network, Tangney says HRS is well positioned to capture a significant chunk of that work.

Even without upgrades such as the Manawatu Gorge project, Tangney, who will continue to manage the company on Works’ behalf, says there’s more than enough maintenance work to keep HRS busy. OnTrack and Kiwi Rail control 4000 kilometres of track, containing six million sleepers, 1787 bridges, 150 tunnels and 12,000 culverts.

Kiwi Rail presently runs 900 freight trains a week and 52 inter-city passenger trains. The biggest rail development on the horizon is the multi-billion-dollar electrification of Auckland’s commuter services, but further down the track the long-held dream of electrifying the entire main trunk line could well become a reality.

In that case, Works’ new acquisition, HRS, could find itself very busily occupied indeed.