‘Power to Timaru’ in Alpine Energy Ltd’s cabling project

‘Power to Timaru’ in Alpine Energy Ltd’s cabling project

Industrial future provided for with major electrical upgrade across Timaru

Timaru is set for a major electricity supply upgrade that will position the central business district, southern city and port for its industrial, commercial and domestic needs of the future.

Electricity supply company Alpine Energy Ltd is preparing to upgrade the current 11 kV supply to 33 kV in a $10 million cabling and switching station project that will cross the city. While the new cable is rated 33 kV, it will run at 11 kV initially, and will be upgraded when a new 33kv supply capability is added by Transpower at its substation.

In a project dubbed Power to Timaru, more than 36 kilometres of 1200 mm2 sheathed alloy cable will be laid in a continuous trench sector by sector from Transpower’s Timaru substation in Old North Road to Alpine’s new switching station in Heaton Street. Six electrical cables will be laid in the trench to provide a double electrical circuit with each circuit having sufficient capacity to operate on its own if the other circuit is out of service for any reason.

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The main trenching work will begin on January 10 next year and at the rate of 600 metres per week is scheduled to take 10 weeks. Some preliminary work will be carried out later this year.

Alpine Energy Ltd chief executive Andrew Tombs said the project, which had been in the pipeline for more than three years, was a forward thinking company approach to providing the region’s existing, new and developing industries within the Port of Timaru, and possible future industries, with a reliable supply.

“Much of this industrial development will be on the southern side of the city and we need to get larger capacity cables into that area to allow industry to grow,” Mr Tombs said.

From Transpower’s Timaru substation, the cable route will take in Old North and Grants Roads, Forth and Andrew Streets, and across parkland, under Selwyn Street, along Leven Street, down Glen Street and Athol Place to Douglas Street, and along to the present Grasmere substation. From there it will snake back through Park Lane, Preston, and Guthrie Streets, along the edge of Lough Park, along Meremere Street, and then takes a right angle south along Le Cren Street, then left on to North Street to Heaton Street via Craigie Avenue.

The total trench length is 6 km. The trenching, at 1.4 metres deep and 1.2 metres wide, will be carried out in 300-metre sections in a stepping stone approach, the company says.

Alpine’s project manager Hayden Darling says this will minimise inconvenience to the public.

He said the project would adopt a multi-company approach with Paul Smith Earthmoving the major trenching contractors, and Hadlee and Brunton involved in boring under areas where trenching was impractical, or too disruptive. The opportunity would also be taken for the laying of an express fibre optic cable duct to allow modern power system control of the new network and switching station, as well as the existing Alpine substations. There will be spare capacity within the ducts that can be used by other ICT service providers.

“Unavoidably, there will be some inconvenience to the public for the short period where the trenches were opened and then later filled on roadways outside private driveways and across bus stops, but we are aiming to minimise that with well posted advisory notices and public information packages as work progresses,” Mr Darling said.

“Some people might return from holiday to find street parking for their caravan or boat more difficult to find, but the disruption should only be for a short time.”

He said the company would observe normal daylight working hours and be sensitive to those for whom access and egress from properties was vital and “those night workers who might be trying to sleep during the day”. The contractors will be working from Monday to Saturday most weeks to ensure they meet their target completion date.

“For this reason we will be signalling our approach to suburbs and places like rest homes well in advance so people have an opportunity to make alternative arrangements if they so wish,” Mr Darling said.

He did not expect major disruption though, or excessive noise.

“It will be a case of normal trenching machinery moving through an area hour by hour. The hole will be opened, ballast (aggregate material to bed the cable) inserted, cables laid and the trench closed in, 300 metres at a time. Most people will not notice undue disruption and apart from the odd spot across footpaths, all work would occur on roadways out from the kerb,” Mr Darling said.

While the travelling excavation project would be well cordoned off from the public as it moved through the city, Alpine would remind people that there would be moving machinery and some potential hazards while the trench was open, he said.

“We would ask the public to respect that.”

ENDS

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