Drone flyover shows big job ahead for repairers of Christchurch's Sumner Rd
Sporadic blasts in the Port Hills herald progress on Sumner Rd, but a drone flyover shows the extent of the work still to be done.
The route over the hills from Sumner to Lyttelton has been closed from Evans Pass since February 2011 due to extensive earthquake damage and geological hazards.
Christchurch City Council (CCC) general manager of city services David Adamson said the repairs were progressing well and the rock stabilisation work was on schedule to finish early next year.
Contractors McConnell Dowell started stabilisation in September 2016, while blasting to break large unstable rocks into a manageable size for removal began two months later.
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Adamson said workers were trying to ensure any dislodged rock was small to minimise damage to the road below.
"They don't want fridges or microwaves falling down, they want things the size of a toaster."
He said stabilisation work would be advanced enough by the middle of the year to allow benching to begin below the Crater Rim Bluffs.
Benching will see a 400 metre-long and 15m-wide "safety shelf" built above the road using explosives and earthmoving equipment.
A 50m bund, a barrier to capture rockfall, will also be constructed in an area known as Double Gully.
Material not being used in the project would be stored in a quarry and used elsewhere at a later date.
The road will be resurfaced once stabilisation is completed, which is expected to be by late February 2018.
Lyttelton Port of Christchurch chief executive Peter Davie said he was pleased the roadworks were underway as the route was an economically important link between the port and the city.
"It also provides an important back-up route for the Lyttelton road tunnel and allows easier access to the port for oversized vehicles and transporting dangerous goods."
Repair costs to reopen Sumner Rd have been estimated at between $40 million and $60m. The New Zealand Transport Agency is footing more than 80 per cent of the bill.
Sumner Rd is one of four projects that make up CCC's Sumner-Lyttelton Corridor Programme, the others being at Wakefield Ave, Moa Bone Point and Shag Rock Reserve. The overall cost of the programme is expected to be $78m.