News

SNOWY 2.0 PROJECT UPDATE – APRIL 2024

01/05/2024

Snowy 2.0 is a major pumped-hydro expansion of the Snowy Scheme and at Marica, high in the Snowy Mountains, a very wide and deep surge shaft connecting to the Snowy 2.0 headrace tunnel is being built.

The surge shaft has two key purposes for the operation of a hydro power station: as a water storage and vacuum relief when the power station starts up, and to absorb the momentum of water movement within the headrace when the power station is shut down.

The Marica surge shaft is about 28 metres in diameter and is currently over 80 metres deep.

During its construction the walls of the shaft are supported temporarily by rock bolts and shotcrete and once it is excavated to its full depth of 250 metres, a permanent concrete lining will be installed from the bottom up.

We are excavating the shaft with a number of excavation methods, including using 36-tonne excavators that place loads of material into kibbles. This material is lifted out and dropped into a dump truck.

An integrated work platform and personnel hoist is in the final stages of commissioning to provide worker access now the shaft is becoming very deep.

In the latest project update, civil engineer and Snowy 2.0 project manager, Richard Clarke, details the significant work undertaken constructing Marica Trail to create a new permanent access road into the surge shaft site.

Marica Trail provides safe, all weather access for traffic, including heavy vehicles.

Building in steep terrain was challenging and required specialised rope access workers to install ground support for safety and stability.

The road has been very carefully constructed in a tight envelope. It’s 6.5 km long, with an elevation change of about 320 metres from top to bottom and multiple water crossings have been created, including over the Eucumbene River.

Over at Tantangara, drill and blast excavation to join the intake and gate shaft is underway from both structures. The transition from the intake changes shape as it is excavated to become the connection tunnel to the gate shaft.

At the same time, we have started drilling and blasting from the gate shaft to merge into the headrace tunnel alignment excavated by TBM Florence.

When completed, water will enter the headrace tunnel from the intake, on its way to the power station.

Snowy 2.0 is being engineered to deliver clean and reliable energy storage and generation for the next 150 years. The target date for commercial operation of all units is December 2028, with first power expected in the second half of 2027.

Update – Thursday 2 May

Reports today that tunnel boring machine (TBM) Florence has stopped tunnelling are incorrect.

TBM Florence remains fully operational and is now more than 800 metres into excavation of the Snowy 2.0 headrace tunnel at Tantangara. The TBM has operated successfully since its restart on 8 December 2023 and has moved through identified soft ground into hard rock.

The total distance tunnelled by all three Snowy 2.0 TBMs across the pumped-hydro renewable energy project is approximately nine kilometres.

As provided in evidence at two recent Senate Estimates hearings, Snowy Hydro has been investigating options to de-risk the headrace tunnel construction by excavating from the other end. This work remains ongoing.

News

SNOWY 2.0 PROJECT UPDATE – MARCH 2024

03/04/2024

This month we’ll update you on tunnel boring machine (TBM) Kirsten, which is putting Snowy 2.0 at the forefront of TBM tunnelling innovation, along with the unique concrete segments she will install as part of the inclined pressure shaft excavation and lining.

Damon Miller, Senior Engineering & Quality Manager for Snowy 2.0, works with the design, manufacturing and construction teams to plan and deliver the engineering solutions behind Snowy 2.0, the pumped hydro expansion of the Snowy Scheme.

Building the inclined pressure shaft (IPS) will be a unique and technically challenging engineering feat for the project team

After finishing the 2.9 kilometre Emergency Cable and Ventilation Tunnel, TBM Kirsten has been substantially modified for her next critical role excavating the IPS.

This very steep, 1.6 kilometre, 10 metre diameter shaft forms part of the waterway and will connect the headrace tunnel with the underground power station.

Project director Dave Evans believes the specially manufactured segments being used for this shaft are going to change the world of hydropower. “It means we can do less steel lining, we can move power stations closer to the surface which is what we’ve done here and construct an inclined pressure shaft with a tunnel boring machine which all makes it safer, quicker and the quality a lot better.”

To see the latest Snowy 2.0 project statistics, view the fact sheet here.

To cope with the extreme and fluctuating water pressures in the IPS, the concrete segment rings lining the tunnel require bespoke connectors.

The Force Activated Coupling System or FACS are specially-developed steel couplers with pin and socket elements.

When the segment rings are interlocked, the pre-stressed FACS keep the joint closed when the tunnel experiences sharp changes in pressure from turbine operations and shut downs. It’s like water hammer when opening or closing a tap at home, just on a much larger scale.

This new technology has been developed by Future Generation joint venture partner Webuild and their designer Lombardi, with the FACS segments being manufactured at our precast factory in Cooma.

A large-scale test is being conducted by installing eight FACS rings to link the emergency, cable and ventilation tunnel with the IPS.

Meanwhile, innovative design by the leading TBM manufacturer Herrenknecht has allowed TBM Kirsten to be modified to safely tunnel uphill.

The machine’s working platforms, equipment and operator’s cabins all pivot to remain horizontal and the walkways become steps and ladderways.

A screw conveyor will move excavated rock from the cutterhead. This feeds into a sandwich conveyor that has face-to-face rubber belts to hold the material so it can be transported down the steep slope without spillage.

The IPS is on a 47% incline so a monorail is being installed to transport workers and there is a rack and pinion system for multi-service vehicle access including segment delivery up the steep slope to the TBM.

News

100,000 SNOWY 2.0 TUNNEL SEGMENTS LOCALLY MANUFACTURED

29/02/2024

The Snowy 2.0 Cooma precast manufacturing facility has hit another significant milestone and completed production of 100,000 of the 130,000 concrete segments needed to line 27 kilometres of tunnels for the pumped-hydro megaproject.

More than 230,000m3 (or more than 550,000 tonnes) of concrete has been used to manufacture these seven-tonne precast segments, installed by the three tunnel boring machines (TBMs) used on the Snowy project.

Snowy Hydro CEO Dennis Barnes said it was pleasing for the project to be manufacturing and investing locally, while also providing employment opportunities.

“About 200 people from the 3,000-strong Snowy 2.0 workforce work at the precast factory operated by our project contractor Future Generation Joint Venture,” Dennis said. “The facility supports local employment and also on-the-job training for a number of school-based apprentices from Monaro High.”

The precast facility includes a concrete batching plant and onsite laboratory to check the quality of every segment produced. Many of the raw materials like aggregates are sourced from local quarries at Mt Mary and Nimmitabel.

Careful consideration and design of the concrete mix, which includes waste material, has meant significant reduction in the environmental production footprint while improving the segments’ durability and performance.

Carousels utilising robotics to automate the process of demoulding, cleaning and application of the release agent on the segment moulds have been used in the manufacturing process.

One of the two carousels has now been modified to produce the precast segments for the Snowy 2.0 inclined pressure shaft (IPS). This very steep 1.65km shaft will be excavated by TBM Kirsten and will link the underground power station with the headrace tunnel coming from Tantangara.

The IPS segments involve a world-first force-activated coupling system (FACS) designed to withstand the powerful internal forces of water moving through the 10-metre diameter inclined tunnel.

Installing segments with FACS eliminates the need for a second tunnel lining, thereby improving the quality, safety and the rate of tunnel completion.

The Snowy 2.0 precast factory will produce approximately 9,000 IPS segments, with nine used in each tunnel-lining ring. The first ring prototype has been completed, with mass production expected to start next month.

FAST FACTS

Number produced = 100,000

Concrete used = About 550,000 tonnes or 230,000 cubic metres

Segment weight = 7 tonnes

Installation method = tunnel boring machine

Equivalent rings (nine segments per ring) = 11,111

Tunnel lining length = 22.2 kilometres

News

SNOWY 2.0 PROJECT UPDATE – FEBRUARY 2024

28/02/2024

The new Snowy 2.0 power station will boast the latest in hydro technology, delivered by our expert subcontractor Voith Hydro. In the latest project update, Snowy 2.0 mechanical engineer Mahali Heffner details how quality assurance activities and factory acceptance testing is carried out on each power station component.

Every one of the hundreds of pump-turbine-generator components undergoes rigorous testing before it leaves the Voith factory. This is to ensure they meet high quality standards and will operate reliably when the power station is switched on.

A team of Snowy Hydro and independent assessors recently conducted mechanical and hydraulic dimensional checks on the first Snowy 2.0 runner at the Voith factory in Shanghai, China.

The runner is the heart of a hydro turbine – it’s the rotating element that drives the generator to produce power.

Acceptance testing includes checking the profile of the blades and surface examinations.

Dye penetrant testing is used to identify imperfections on the surface of the 31 tonne, 4.2 metres-wide runner. We spray on a red dye, clean it and apply the developer. If imperfections are present, the dye will make them visual.

Snowy Hydro and contractor Future Generation Joint Venture (FGJV) work with Voith and other subcontractors on a range of quality assurance activities as part of the multi-stage manufacturing process.

At Lobs Hole in the Snowy Mountains, power station components including turbine guard valves, spiral cases and draft tube liners are being progressively delivered to site.

Meanwhile, deep underground, excavation of the machine hall and transformer hall cavern crowns have been completed and we’ve almost finished the final side slashing to widen the structures. Drill and blast works are also continuing in the cross passages and tunnels that are an important part of the power station complex.

At the other end of the project at Tantangara, the intake is really starting to take shape. We are well into stage two of the excavation, now approximately 49 metres below ground level and approximately six metres to go.

We map the cut face to determine what rock support is required and then after the design is confirmed, rock bolts and shotcrete are installed. It’s exciting to see the shape of the transition from intake to tunnel, with the canopy tube rock support in the intake face forming an arch above the tunnel entrance.

Drill and blast of the tunnel excavation is scheduled to start soon and the first milestone target will be to link up the intake with the gate shaft.

News

BREAKTHROUGH MILESTONE FOR SNOWY 2.0

05/01/2024

Snowy Hydro is pleased to announce another major achievement for the Snowy 2.0 pumped-hydro project, with the breakthrough of the final three metres of the power station’s 223-metre long transformer hall cavern crown.

The Snowy 2.0 delivery team began excavating the transformer hall and machine hall caverns in June 2023. The Snowy 2.0 power station will be located approximately 800m underground at Lobs Hole in the Snowy Mountains. When completed, the machine hall will be 251 metres long and 52 metres high and the transformer hall 223 metres long and 46 metres high. Together they will form one of the largest and deepest caverns in the world, big enough to fit the Sydney Opera House inside.

Precise drill and blast methods are used to profile the curved cavern crowns (or ceilings) and break up the rock, which is mucked out and followed by surface scaling to remove any remaining loose rock. The exposed solid rock face is then supported with rock bolts and shotcrete. The excavation sequence of the cavern crowns is carefully planned and executed, as the rock mass relaxes and moves inwards as the excavated void increases. These movements are expected and are closely monitored during the process.

So far, about 17,000 cubic metres of material has been excavated from the central heading of the transformer hall cavern crown. The heading has been advanced in 3-4 metre rounds from either end of the cavern for a total of 77 blasts.

The machine hall cavern crown breakthrough will take place in coming weeks, and widening of both cavern crowns, known as side slashing, is ongoing and planned for completion in coming months. Excavation of both power station caverns is set to continue through 2024.

The breakthrough of the transformer hall cavern crown represents another important milestone for the Snowy 2.0 pumped-hydro project that will significantly expand the existing Snowy Scheme and will provide an added 2,200 megawatts of on-demand power and 160 hours of large-scale renewable energy storage for the National Electricity Market.

Snowy Hydro CEO Dennis Barnes said: “The breakthrough of the transformer hall cavern crown is a really pleasing milestone for the Snowy 2.0 team, reinforcing that we’re making good progress with our underground drill and blast excavation activities. We are well on our way to delivering the largest single project that will help ensure Australia’s secure and reliable transition to renewable energy.”

News

SNOWY 2.0 PROJECT UPDATE – DECEMBER 2023

19/12/2023

In December’s Snowy 2.0 update, Snowy Hydro CEO Dennis Barnes recaps progress and key events throughout the last 12 months.

The review and reset of the pumped-hydro Snowy Scheme expansion project has been a major milestone in 2023.

The reset has put Snowy 2.0 on a robust and sustainable footing, with new contract arrangements in place and a revised cost of $12 billion. The full commercial operation date for the new 2,200 megawatt power station is December 2028.

The focus for the project is prioritising safety and environmental outcomes while achieving construction program targets.

Meanwhile tunnel boring machine (TBM) Florence is underway again at Tantangara after a significant period paused in soft ground conditions after a surface depression formed above the cutterhead. Following an extensive process of ground stabilisation, the project has recently received NSW government approval for a planning modification, enabling the machine to restart tunnelling the headrace adit.

Progress highlights for 2023 include TBM Lady Eileen Hudson being relaunched in July to excavate her second tunnel for the project – she’s now one kilometre into the tailrace tunnel.

There are more than 2,700 people employed on Snowy 2.0 and a total of 20 million hours have been worked to date.

Drill and blast excavation of the power station cavern crowns is well underway from both ends of the machine and transformer halls and we’re seeing large power station components manufactured by Voith Hydro delivered to site.

Senior electrical quality engineer Victor Teo is in Shanghai, China, where Voith is fabricating some of the key electrical components for Snowy 2.0, including stator bars, rotor bars and poles.

The stator bars are bent to a precise shape and highly specialised insulation tape is applied by both machine and technician. These bars are part of the generator which is connected to the transformer to deliver electrical current.

Insulation resistance and short circuit tests are conducted on every bar to ensure compliance with our engineering requirements and Australian Standards.

468 stator bars are needed for each of the six pump-turbine generator units, so over 3,000 of them including spares will be produced.

There is always a member from the Snowy Hydro team in China to conduct quality assurance activities, monitor progress, act as a conduit to close out technical issues and to conduct Factory Acceptance Tests

Snowy 2.0 project manager and environmental engineer Emily Martin is at Tantangara, where TBM Florence is tunnelling in slurry, or closed, mode. This mode utilises the onsite slurry treatment plant and allows the team to pressurise the ground around the TBM to provide additional stability.

The intake excavation works at Tantangara are progressing well, with stage 2 well underway.

This involves another 78,000 cubic metres of drilling and blasting earthworks, along with rockbolt installation and shotcreting.

The intake excavation, which is where water will enter the headrace tunnel, is currently about 35 metres deep and it will be extended to a total depth of 55 metres.

News

SNOWY 2.0 PROJECT UPDATE – NOVEMBER 2023

05/12/2023

Snowy 2.0 is entering an exciting phase as we build the largest single project that will help ensure Australia’s secure and reliable transition to renewable energy.

In this month’s project update Hamish Pryor, construction director for Snowy 2.0, provides an overview of the power station equipment manufacturing that is in full swing.

The bespoke Snowy 2.0 power station components are being fabricated with precision and skill at one of Voith Hydro’s global production facilities in Shanghai, China.

Voith Hydro is partnering with Snowy 2.0 to make the six pumped hydro units that will generate up to 2,200 megawatts of power for Australia’s electricity grid.

Voith has more than 150 years of experience in hydropower systems and its highly skilled team is developing efficient and reliable equipment that will support the 150-year design life of Snowy 2.0.

At the Shanghai factory, every item that is manufactured for the project undergoes comprehensive quality checks and testing before being shipped to Australia.

Voith’s quality, research and development team in Germany works directly with its Shanghai engineering experts on design, manufacturing processes and quality control. The team also collaborates closely with the Snowy 2.0 project team in Australia.

Among the large components being manufactured are the 13 metre-wide spiral cases and the main inlet valves – each weighing 140 tonnes and 2.2 metres in diameter – and the 31-tonne runners.

The runner is the heart of a hydro power turbine – it’s the rotating element that drives the generator to produce electrical energy. Exceptional machining and highly specialised welding skills are used to fabricate the components.

In Voith’s state-of-the-art electrical workshop more than 2,700 stator bars – which will be connected to the transformers to deliver power produced in the generators – are being manufactured.

Snowy Hydro has team members based in Shanghai to conduct quality assurance activities and monitor progress, while specialist mechanical and electrical engineers attend factory acceptance testing.

Recently, the final acceptance test for the first unit runner was completed and celebrated with a photo in the workshop.

In the Snowy Mountains in NSW, the Snowy 2.0 delivery team is also creating water intakes at the Talbingo and Tantangara reservoirs. A 28-metre diameter, 250 metre-deep surge shaft is being built at Marica and will become one of the largest operating shafts in the world.

Tunnel boring machines excavating the Snowy 2.0 tunnels are lining them with locally-made concrete segments – we’ve manufactured almost 90,000 of them at the Cooma precast factory so far. And the underground power station cavern complex is underway, with drill and blast excavation.

News

SNOWY 2.0 PROJECT UPDATE – OCTOBER 2023

08/11/2023

In this month’s project update, we check on tunnel excavation at Talbingo, progress at the upstream surge shaft at Marica, and we hear about the specialised drilling underway to prepare for services such as power and communications between Lobs Hole, Marica and Tantangara.

Will Binsted, Snowy 2.0 Lobs Hole Construction Manager, has been working on the project for four years and is responsible for coordinating both surface and underground works. Will, who lives locally in Tumut, liaises with technical specialists as well as designers and project engineers across the busy worksite.

To see the latest Snowy 2.0 project’s statistics, view the fact sheet here.

A complex task is underway at Lobs Hole to drill boreholes for the pipes that will house power, water and fibre optic cable for communications across three of the Snowy 2.0 sites.

Horizontal directional drilling (HDD) is being used to drill 2.2km-long boreholes from Lobs Hole to Marica. The holes are initially 300 millimetres in diameter and have an elevation difference of 650 metres.

Two drilling operations are underway from top and bottom and will join up to create a continuous borehole before being enlarged to 660 millimetres in diameter.

This type of drilling is used for service lines that cross under waterways or underground structures and requires a high level of skill to maintain directional control while operating a drill string up to 1.8km long. Snowy 2.0 has contracted HDD experts Michels for the project.

The boreholes eliminate the need to construct approximately five kilometres of roads and excavate up to 60 metre cuts in the steep terrain, helping the Snowy 2.0 project team minimise environmental impacts.

HDD techniques will also be used to take services under the Snowy Mountains Highway and waterways across the plateau through to the Tantangara worksite.

At Marica, the 28 metre diameter headrace surge shaft is now one-fifth of the way to its final depth of 263 metres and we’re starting drill and blast activities. There are two hoisting buckets called kibbles with a capacity of 25 tonnes for loading out excavated rock.

Excavators break up the rock with hydraulic hammers before it’s loaded into the kibbles and craned out of the shaft. The kibbles are lowered into hoppers and the rock drops into an articulated dump truck before being removed to a temporary stockpile area.

With the shaft now more than 50 metres deep, an integrated work platform and personnel hoist is being installed to provide worker access. We’ve installed ventilation ducts to manage air quality.

At Talbingo, tunnelling of the tailrace adit is complete. TBM Lady Eileen Hudson is now excavating the tailrace tunnel alignment and heading towards the power station complex. This marks the start of the first power waterway on the Snowy 2.0 project.

Excavation is ahead of schedule, with more than 26 metres recently excavated in a single day. The tailrace tunnel is six kilometres in length, with TBM excavation continuing through to mid-2025.

News

SNOWY 2.0 PROJECT – COMMUNITY INFORMATION SESSIONS IN NOVEMBER

02/11/2023

Interested in the latest updates from the Snowy 2.0 renewable energy mega project?

Snowy Hydro and Snowy 2.0 principal contractor Future Generation Joint Venture are inviting local community members to attend information sessions being held throughout the Snowy Mountains in November.

These in-person events enable locals to be updated about the project, ask questions and provide feedback. Hear from the Snowy 2.0 team about:

the recent project reset
project progress, construction activities and news
traffic management, environment and safety
accommodation, recreation access and other local issues;
local suppliers, jobs and training on Snowy 2.0.

Snowy Hydro CEO Dennis Barnes said with a significant public focus on Snowy 2.0 in recent months, the sessions provided opportunities to find out more directly from project team members.

“We are committed to being open and transparent with you – our local communities – about our large and complex pumped-hydro project. A project of this scale and complexity has, and will, face challenges, but we continue to make solid progress across our construction and manufacturing operations.

“Snowy 2.0 is being engineered to deliver clean and reliable storage and electricity generation for Australians for the next 150 years. It is a project that is generating jobs and significant investment in regional areas.

“I encourage everyone to come along to one of our community information sessions to hear the latest about Snowy 2.0, discuss any local concerns that you may have and ask questions.”

The Snowy 2.0 community information sessions in November will be held in Talbingo, Tumut, Tumbarumba, Cooma and Adaminaby.

There will be some drop-in sessions, with the chance to speak one-on-one with project team members, and events featuring a formal presentation followed by community Q&As.

Community information sessions schedule:

Date	Town and location	Time
Wednesday 8 November 2023 Wednesday 8 November 2023	Talbingo shops Tumut River Brewing Co	12.00pm-2.00pm 6.00pm-7.30pm
Thursday 9 November 2023	Near Tumbarumba IGA, The Parade	12.00pm-2.00pm
Tuesday 14 November 2023	Cooma Car Club	6.00pm-7.30pm
Wednesday 15 November 2023	Adaminaby Bowling Club	6.00pm-7.30pm

News

SNOWY 2.0 PROJECT UPDATE – JULY 2023

28/07/2023

July marked an exciting milestone for Snowy Hydro, the Snowy 2.0 project and for one of its three tunnel boring machines. Tunnel boring machine (TBM) Lady Eileen Hudson was the first machine to start tunnelling on the pumped-hydro mega project, the first to complete a tunnel and is now underway on her second tunnel excavation.

Snowy 2.0 senior project manager, Rodd Brinkman, is onsite at the Talbingo adit, where teams have been preparing to relaunch TBM Lady Eileen into the mountain.

The TBM will excavate the 6km tailrace tunnel to connect Talbingo Reservoir to the underground power station complex. Water used to generate 2,000 megawatts of power from Snowy 2.0 will flow out of the tailrace tunnel. Water also enters this tunnel when the power station is pumping.

After completing the 2.8km main access tunnel (MAT) in 2022, it has been a big task to disassemble and safely extract TBM Lady Eileen and reassemble her with new components before commissioning. The conveyor stacker, grout batch plant, and chiller plant were also relocated from the MAT portal to the Talbingo adit.

Before a TBM begins her journey underground, it is traditional for the machine and crew to be blessed for a safe journey under the watch of St Barbara, the patron saint of tunnelling and underground work. The tradition of blessing is acknowledged at tunnelling sites all over the world.

Local parish priest Father Mark Croker blessed the TBM at an onsite ceremony with many Snowy 2.0 workers in attendance. The machine was then switched on and began cutting the rock face. This is the fourth TBM launch for Snowy 2.0 and a major achievement for the Snowy Scheme expansion project.

TBM Construction Manager Derek Whelan manages all Snowy 2.0 tunnelling activities, as well as the TBM construction personnel. He was on-hand to run through Lady Eileen’s impressive components, including a new 378-tonne cutterhead.

The cutterhead is made up of 70 cutting discs each weighing 290 kilos that will excavate the varying geology of the 11-metre diameter tunnel. At 137 metres in length and weighing 2,300 tonnes, the TBM is a moving factory with many parts working together in a complex operation.

More than 27,000 concrete segments manufactured at the Polo Flat, Cooma, precast facility will be used to line the tailrace tunnel with the segment erector, segment feeder, segment cranes, and sophisticated grouting system all onboard the TBM.

The TBM is also equipped with a guidance system that provides data to the machine’s pilot, to the nearest millimetre. This information is mirrored above ground and monitored by Snowy 2.0’s construction and engineering teams.

Snowy 2.0: Underpinning Australia’s transition to a renewable energy future

News

SNOWY 2.0 PROJECT UPDATE – JUNE 2023

26/06/2023

In the June update of the pumped-hydro expansion of the mighty Snowy Scheme, Snowy 2.0’s Alex Woschitzka explains construction progress at the massive Talbingo and Tantangara intakes. The project’s Quality Coordinator also checks in on the transformation of a narrow fire trail through steep terrain into a road suitable for heavy vehicles.

Significant progress has been made at the Talbingo intake, where water will exit the tailrace tunnel when Snowy 2.0 generates power. This is also where water enters the tunnel for pumping.

Construction teams have moved more than 310,000 cubic metres of earth to date, about half the total amount that will need to be moved. More than 24,000 metres of rock bolts have been installed and 8,300 square metres of shotcrete sprayed to support the wall.

As part of quality assurance, the shotcrete must be tested for compressive strength. Samples are taken from the truck and also cored from the face to ensure it meets the intended strength requirements. For the rock bolts, pull-testing is conducted to ensure they have been correctly installed, and meet the design and quality requirements.

When completed, the total height of the Talbino intake excavation will be 104 metres, with about 31 metres of that below the water level. The concrete intake structure will be an impressive 50 metres in height.

Construction is well underway on an internal access road through mountainous terrain. With the help of Snowy 2.0 subcontractor Leed, a narrow fire trail will be widened into a six-kilometre road to enable heavy vehicles to access a rock emplacement area on Talbingo Reservoir.

Works began from both ends across very challenging terrain, achieving a major milestone recently when the two pioneering fronts joined across the Middle Creek cliffs. A temporary bridge with a 36-metre span has been installed across Middle Creek and is capable of supporting a fully-loaded 80-tonne dump truck.

In another milestone achieved in June, stage one earthworks have now been completed at the Tantangara intake. The first stage involved excavation of about 205,000 cubic metres of earth with a further 78,000 cubic metres of drilling and blasting earthworks expected in the next stage.

To support the excavation, more than 18,000 metres of rock bolts have been drilled and installed, and approximately 6,100 square metres of shotcrete sprayed. The excavation is currently about 26 metres deep and will be extended to a total depth of 55 metres.

Tantangara intake is where water will enter the headrace tunnel when the Snowy 2.0 power station is in generation mode. When in pumping mode, water will exit through the intake and fill Tantangara Reservoir.

News

SNOWY 2.0 PROJECT UPDATE – MAY 2023

30/05/2023

May was a milestone month for the Snowy 2.0 team with the completion of the emergency, cable and ventilation tunnel, or ECVT – another vital step in the construction of Snowy Hydro’s new pumped-hydro expansion megaproject.

Snowy 2.0 senior project manager Rodd Brinkmann explains the next stage of the project from his base at Lobs Hole, as preparation for excavation for the underground power station cavern gets underway.

The ECVT is a 2.93 kilometre tunnel that runs adjacent to the main access tunnel and provides alternate access to the site of the underground power station. Tunnel boring machine (TBM) Kirsten recently completed excavation of the ECVT and will soon start tunnelling the inclined pressure shaft. This very steep shaft links to the headrace tunnel from Tantangara Reservoir.

TBM Kirsten will need to undergo modifications to excavate the 25-degree incline, including installation of a screw conveyor to extract excavated rock from the cutterhead to a sandwich conveyor system. With such a steep incline, construction of the 1.45km shaft with its concrete segment-lined tunnel, will be a world first.

In the main access tunnel, or MAT, construction of cross passages and construction access tunnels is well underway with 850 metres of drill and blast tunnel excavation completed. Of the five cross passages linking the MAT and the ECVT, two are fully excavated and waiting on breakthrough into the ECVT. Key construction tunnels are also being excavated to provide access to the machine hall, transformer hall and the top of the tailrace surge shaft.

Workers have reached the main cavern areas from both ends and will soon commence excavation and support of the cavern crowns or ceilings of the power station halls. The excavation sequence of the cavern crowns is critical, as the in situ rock mass will relax and move inwards as the excavated void increases. These movements will be closely monitored during the process. Geotechnical drilling and plate load tests will measure and confirm the characteristics of the rock geology around the power station.

Dynamic 3D models of the power station caverns are also being used. 3D models are created using digital engineering to transform 2D design drawings and are displayed in the state-of-the-art immersive theatre at Snowy Hydro’s Discovery Centre in Cooma, where Snowy 2.0 engineers can collaborate with power station design experts from around the world. Once construction is complete, the detailed 3D models will be a valuable tool for asset maintenance.

With so much activity in the tunnels, the current Snowy 2.0 underground workforce will increase by another 200 people in the coming months.