Battle To Solve Manawatu Gorge Slip


NZTA crews have finished cutting a path through dense bush to reach the top of the Manawatu gorge slip, and are clearing bush to establish a safe working platform for the earth moving equipment due to start benching (terracing) the slip early next week.

NZTA state highways manager David McGonigal says while the heavy wind and rain in the gorge this week had not increased the slip noticeably, it had made conditions at the top of the slip difficult.

“We’re very keen to get stuck in to clearing the slip, but we are also very mindful of the safety of our contractors. They are working in difficult conditions and it’s essential that we establish a safe working platform before our drivers move in to start work.”

Manawatu slip | NZTA

Mr McGonigal said a key piece of equipment to be used in the slip clearance was a large Allis Charmers HD16 bulldozer that has had its blade removed and works a high-strength winch. The large machine – known as ‘The Bandit’ - would be vital to the benching process.

“This is a huge machine with extremely good torque and can winch up to 48 tonnes. It’s been used to recover everything from swamp Kauri logs to tipped over trains. It will be half buried in the ground, and it will anchor our heavy machinery when it’s working at the top of the slip face. It’s a key element in our safety controls and has already proved its worth in cutting the track to the top.

“The team also had to enlist the help of a helicopter to get larger items of essential plant and equipment up to the top of the slip (including equipment storage and portaloos). Heavy rain has made conditions at the top of the slip very difficult, so we are working hard to get a safe working platform established before drivers start benching the slip on Monday.”
Meanwhile, one of the three new slow vehicle bays on the Saddle Road is now complete and construction of the other two are well underway.

Crews are continually monitoring the state of this route and making repairs as required. Speed limits of 30km/hr are in place along the alternative routes to calm traffic through difficult sections of road and a work programme is underway to complete the necessary repairs as soon as possible. This includes teams working at night.

Following discussions with the NZTA, Horizons Regional Council has also advised that the stretch of Manawatu River 200 metres either side of the slip will be closed from Monday November 28 until the land above is stable. This is to protect all river users from falling debris that may be dislodged from the earthworks above.




  1. Ian says:

    Rail engineers definitely chose the better side for the rail line all those years ago.

  2. Rob says:

    They weren’t dummies…they could see even back then, that geologically, the southern side was not worth putting either road or rail on.

  3. Kegan says:

    Not true. Both sides are similar geologically. Main difference is that the road has been widened and realigned several times cutting away and destablising the slope. Rail hasn’t been in general (with the expection of daylighting three short tunnels at the eastern end of the gorge).

  4. Rob says:

    Kegan, cheers. I stand corrected. Thanks.

  5. Anthony says:

    They should build a cover and viaduct like they did at Otira.

  6. ingolfson says:

    “They should build a cover and viaduct like they did at Otira.”

    Over the whole length of the gorge??? Or is this only one single danger spot (I suspect not).

  7. brendan says:

    One day the area on the Southern Bank of the Manawatu Gorge will be known as the “Manawatu Flats” .Because the whole Southern Bank will have to be terraced or flattened. I fear for the rate payers , even though the NZTA is picking up the tab , the councils certainly have a had a lot of extra work to do and associated costs .

  8. Matt L says:

    Just last year there was a decent slip on the northern side that closed the rail line for a while, a train even crashed into it but luckily managed the driver wasn’t really injured and the train was not to seriously damaged.

    As for the road, it carries on average just under 7000 vehicles per day so probably hard to justify huge expenditure.


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