A recently constructed pedestrian bridge is expected to be an important safety feature for Snowy Hydro staff to access a mini-hydro power station at Talbingo.
The bridge, which was completed around mid-year, runs from the Jounama Dam wall to the power station.
The station silo has been difficult for staff to access previously and has often necessitated a boat trip when water levels were high with a climb up and down steep stairs.
Although construction took 18 months from schematic design to completion, work was often dictated by Blowering’s fluctuating water levels.
Completed at the start of September, the 76m-long bridge with handrails and stairs to the dam wall provides 24/7 all-weather staff access to Jounama Power Station.
The construction project took more than 8,000 personnel hours of planning and execution.
The head contractor selected for the bridge construction – SRG Global – has strong ties to the region, after being established in 1961 when the company founder provided Swiss-made post-tension rock anchors during construction of the Snowy Mountains Scheme.
In addition, a range of regional businesses provided services and materials for the bridge, including excavation for footings which were carried out by Machell Brothers, Tumut, bridge sections assembled onsite by Tumut’s Roddy Engineering and LED lighting in the handrails installed by Sturt Electrical Services. Bridge platform sections, stairs and handrails were also fabricated and galvanised by DJ Lynch in Gundagai.
The bridge is designed for long-life, with about 280 cubic metres of concrete used for the piers and 25 tonnes of steel reinforcing.
Each of the three bridge spans are about 25m long and weigh 13 tonnes.
Snowy Hydro’s Lower Tumut Area Manager Guy Boardman said the reason the bridge hadn’t been constructed previously was because Snowy Hydro didn’t have control of the water level – which is constantly fluctuating and controlled by Water NSW. He said this had to be taken into account for the bridges construction.
“We were unsure how long it would be an island, which was why construction took some time. There is quite a period of time where it is surrounded by water and the only way to access it for my team is by boat,” Mr Boardman said.
“When the dam becomes full, the power station becomes an island surrounded by water which is the reason why the concrete silo is as high as it is – it had to be the same height as the Blowering dam wall.”
Work carried out at the station on a regular basis consists of general maintenance activities and general inspections.
Work teams had typically accessed the station by boat, and at times a dangerous task, especially when machinery and equipment was needed to be transported to the site.
“The safety risks of multiple people getting in a boat was always problematic. It was a significant amount of money to install the bridge but Snowy Hydro has safety as it’s number one priority and we spend what we have to ensure the safety of personnel,” Mr Boardman said.
“The risks were many, not only in terms of boat safety being an issue but the simple fact that Blowering is still an alpine waterway and in winter it would be freezing,” he said.
“Whenever we had to take parts of machinery, doing that by boat was a more significant safety issue, not to mention the risks of needing to go there at night.
“This bridge now gives us much greater flexibility as a regional team to access the power station and we now have safe access to the power station 24/7.”
Mr Boardman said the company prided itself on having employed local businesses for the construction of company assets such as the new bridge.
“We very much turn to getting local business involved,” he said. “In terms of negotiations, we always wanted to support local businesses in insuring they have a stake in the game. We take our local industry very serious,” he said.