News

SNOWY 2.0 TUNNEL PROGRESS AND CONSTRUCTION UPDATE

01/11/2024

The Snowy 2.0 pumped-hydro megaproject has marked a significant milestone, with one of three tunnel boring machines (TBM), Lady Eileen Hudson, now two-thirds of the way through its second tunnel excavation.

The TBM is approximately four kilometres into the six kilometre ‘tailrace’ tunnel, which will link the lower Talbingo Reservoir with the massive 20-storey underground power station. TBM Lady Eileen Hudson previously completed a 2.85 kilometre main access tunnel, which is now being used by construction teams to reach the underground power station site.

Drill and blast works are also advancing at the Talbingo water intake, creating a new 700-metre tunnel between the intake structure and the tailrace tunnel. The Talbingo intake is located in very steep terrain and following excavation of 570,000 cubic metres of material over two years, the rock face is now 110 metres high.

Snowy Hydro CEO Dennis Barnes said that recent months have been some of the project’s most productive.

“Overall the project is around 60 percent complete and there’s a strong sense of momentum, with good tunnelling progress by TBM Lady Eileen and other two TBMs performing well,” Mr Barnes said.

“Snowy 2.0 is one of the most complex and challenging megaprojects underway in the world. There is an immense sense of pride in what’s being achieved across the workforce of more than 3,000 people.”

Mr Barnes said Snowy 2.0 will be the most significant addition to the National Electricity Market (NEM) since the original Snowy Scheme.

“Snowy 2.0 will have a generating capacity of 2,200 megawatts and an unmatched 160-hour storage capability, meaning it will be able to power around 3 million homes for a week,” Mr Barnes said.

“While batteries and gas are important to store the excess energy from the increasing amounts of wind and solar in the grid, only pumped hydro can offer the long-duration storage needed to keep the lights on and smooth energy price peaks during extended periods without enough sun and wind.”

Snowy 2.0 is on track to be delivered within the $12 billion budget and be complete by the end of 2028.

Across the project, more progress is being made:

In the underground power station complex, the caverns are more than 27% excavated.
- All 196 of the very large brackets that will hold the temporary construction cranes to build the underground power station have been installed in the two power station caverns.
- When fully excavated, the Snowy 2.0 power station will be the equivalent of a 20-storey, 250 metre-long building, located 800 metres underground.
At Marica, the 28-metre wide surge shaft is excavated to 123 metres, or half of its final depth. The shaft will provide water storage when the power station starts up and pressure relief in the headrace tunnel when it shuts down.
TBM Florence is progressing well, excavating the 17-kilometre long ‘headrace’ tunnel that will link the upper Tantangara water reservoir to the underground power station, with more than 1,600 metres excavated. TBM Kirsten is performing to plan and is now excavating the 1.6-kilometre, very steep tunnel that will link the headrace tunnel to the underground power station. Ground conditions ahead of all TBMs are expected to be inconsistent and the performance of the machines will vary as a result.
The NSW Department of Planning, Infrastructure and Housing is currently assessing the planning modification to enable a fourth project TBM, which is required to tunnel through a challenging geological fault zone.
Snowy 2.0 is focused on health and safety above all else. While health and safety performance is encouraging, it is an area in which the project is continually monitoring and looking to improve further:
- The project’s current total reportable injury frequency rate (TRIFR) is 2.42^*. ^*Calculated per million hours worked. Current total work hours are 27.8 million.
- The current lost time injury frequency rate (LTIFR) is 0.92.

News

SNOWY 2.0 CONFIRMS FOURTH TUNNEL BORING MACHINE TO PROTECT DELIVERY TIMELINE

23/08/2024

A new tunnel boring machine will be deployed to help keep Snowy 2.0 on its delivery timeline, subject to approval by the NSW Department of Planning, Housing and Infrastructure.

New ground testing techniques have provided a better understanding of the full extent of a complex fault zone on the route of the 17 kilometre tunnel that will connect Snowy 2.0’s upper reservoir to its underground power station.

Snowy Hydro CEO Dennis Barnes said activating a fourth tunnel boring machine is the right course of action, given that what is now known about the tunnelling challenges ahead has provided the opportunity to mature the design.

“We’ve always known the fault zone was there and I’ve said in the past we will need to take action,” Mr Barnes said.

”While the fault zone is not a surprise, further ground testing since the project reset has revealed it is far more geologically challenging than earlier investigations indicated.

“We’ve carefully considered a range of options to get through the fault zone and overcome the initial design immaturity. Bringing in a fourth machine is the best way to keep the Snowy 2.0 on track for its target completion date of December 2028.”

A modification for Snowy 2.0’s project approval has been submitted to the NSW Department of Planning, Housing and Infrastructure, and will be subject to the Department’s independent community consultation and assessment processes.

The planning modification seeks approval for a change to construction methods within the project’s already approved work zone. There is no proposal to increase approved land clearing areas, surface or groundwater impacts. Local communities will be consulted about relevant changes to construction methodologies.

“We’re mindful that we are building Snowy 2.0 in a precious and protected national park. We have worked diligently to arrive at a proposal that does not step outside our existing construction area or increase our already approved impacts,” Mr Barnes said.

Mr Barnes said he remains committed to transparency regarding the project, given the inevitable challenges ahead.

“Just like the construction of the original Snowy Scheme, this is one of the most challenging and complex megaprojects underway in the world,” he said.

“The fourth tunnel boring machine is an example of adapting to the situation in front of us, so we are doing everything we can to safely meet Snowy 2.0’s delivery timeline.”

While the need for a new tunnel boring machine is driven by new information about the fault zone, Mr Barnes acknowledges that the disappointing performance of Florence, the tunnel boring machine excavating the same tunnel that the new machine will also work on, has contributed to the need to take significant action.

“It’s difficult to say with certainty whether the same action would be needed if Florence had performed as we had hoped. However, it’s likely that the fourth machine would still be needed,” Mr Barnes said.

Snowy 2.0 will help underpin Australia’s transition to renewable energy through its ability to generate enough flexible, fast-dispatch energy to power 3 million homes continuously for a week.

The unmatched scale and duration of Snowy 2.0’s storage and generating ability will effectively provide the network with critical electricity supply insurance against extended periods without enough wind and sunlight. Most other forms of storage, including batteries, can only generate power for a handful of hours.

According to AEMO (the Australian Energy Market Operator), Snowy 2.0 will supply a majority of the National Electricity Market’s storage needs, greater than every other storage asset combined.

“Snowy 2.0 is critical to Australia’s energy future. We need to get this job done,” Mr Barnes said.

Subject to planning approval, the new machine will be tunnelling before the end of 2025.

News

SNOWY 2.0 UPDATE

18/07/2024

The Snowy Delivery team has completed 570,000 cubic metres of excavation of the Talbingo intake. The intake is where water will exit and enter the tailrace tunnel, connecting the lower Talbingo reservoir to the underground power station
Excavation of the Marica surge shaft has reached 95 metres. Mechanical excavation including rock breakers and excavators continues, with drill and blast methods also being used. Once complete, the 28 metre-wide and 250 metre-deep surge shaft will be used for water storage and pressure relief when the power station starts up, and to absorb the momentum. The Marica surge shaft will be one of the largest shafts of its type in the world
Excavation of the gate shaft at Tantangara is complete, with drill and blast work to excavate the transition tunnels linking it and the intake well advanced. The gate shaft is used to stop and start the flow of water into the headrace tunnel and power station for maintenance purposes or in the case of an emergency

Tunnel Boring Machines (TBMs)

Florence

Florence is the TBM excavating the 16 kilometre headrace tunnel, which will connect the underground power station to the upper Tantangara reservoir

Following a seven-week operation to use ultra high pressure water jetting to remove very hard rock preventing the TBM from progressing, TBM Florence restarted excavation on Thursday 11 July

The Snowy delivery team expects highly variable ground conditions to continue ahead of TBM Florence, which will mean progress will continue to vary, particularly as the TBM navigates the curve leading to the main tunnel alignment

Lady Eileen Hudson

TBM Lady Eileen Hudson, which has completed the 2.8 kilometre main access tunnel to the power station, is now excavating the 6 kilometre tailrace tunnel, which will connect the underground power station to the lower Talbingo reservoir

The machine is progressing well and is approximately 3.0 kilometres into the tailrace tunnel

A conveyor belt extension and service modifications have recently been carried out so excavations to join the tailrace tunnel with the Talbingo intake excavation can commence

Kirsten

Kirsten is the TBM excavating the 1.6km Inclined Pressure Shaft (IPS – connecting the underground power station to the headrace tunnel that leads to the upper Tantangara reservoir), having already completed the 2.9km emergency, cable and ventilation tunnel

TBM Kirsten has installed 14 trial tunnel lining rings in the IPS using locally manufactured concrete segments specifically designed for the high water pressures that will be experienced in the IPS

Tunnelling of the IPS will be a pioneering engineering challenge, with the shaft’s incline reaching a steep 47 percent

News

SNOWY 2.0 AND TBM FLORENCE UPDATE – JUNE 2024

01/07/2024

At Tantangara in the NSW Snowy Mountains, we’re building critical infrastructure for Snowy 2.0, the major pumped-hydro expansion of the Snowy Scheme.

In the headrace tunnel, specialist contractors are continuing to conduct hydro blasting work to remove rock pinching on the shield of tunnel boring machine (TBM) Florence.

The Snowy 2.0 team stopped TBM Florence in May when extremely hard and abrasive rock conditions wore down cutter disks on the edge of the cutterhead very quickly as it traversed a curve in the tunnel.

In recent weeks we have moved TBM Florence forward in small increments several times and the machine remains fully operational.

The high pressure hydro blasting breaks up and disintegrates the surrounding rock so TBM Florence can navigate the curve onto the straight headrace tunnel alignment.

In the June project update, Snowy 2.0 tunnel engineer Nick Chapman, who oversees tunnel design and provides technical engineering support for construction activities, highlights progress at the Tantangara Reservoir intake and gate shaft, along with underground works to connect the two.

The gate shaft is one of the key structures in the overall Tantangara intake system, which also includes the intake diffuser, tunnel transitions and headrace tunnel.

The main function of the gate shaft is to stop and start the flow of water into the headrace tunnel and power station for maintenance purposes or in the case of an emergency.

Now the gate shaft is excavated, work is focused on the two transition tunnels either side.

These tunnels are well advanced, with the full length of the top heading complete and excavation to the invert on schedule for completion in July.

The intake is now approximately 45 metres deep – the remaining excavation is being coordinated with work on the third transition tunnel.

The next stage of the intake earthworks will involve the removal of the temporary “rock plug” and excavation into Tantangara reservoir, to allow water to flow through the intake and into the headrace tunnel.

That’s something to look forward to in future updates!

News

TBM FLORENCE UPDATE – 12 JUNE

12/06/2024

High pressure water jetting continues to be used to remove rock impinging on the shield of Snowy 2.0 tunnel boring machine (TBM) Florence at Tantangara.

The TBM was halted by the project team in extremely hard and abrasive rock conditions on 16 May, with specialist contractors commencing on 21 May.

The high pressure water jetting technique to remove the rock is ongoing and working well.

We expect highly variable ground conditions to continue ahead of TBM Florence in the headrace tunnel.

Water jetting device mounted on the TBM cutterhead, with the machine’s shield on the left of the image and the rock on the right. The device directs a high-pressure water stream at the rock, causing the rock to break apart and disintegrate.

News

TBM FLORENCE UPDATE – 30 MAY

30/05/2024

The use of high pressure water jets to remove rock impinging on the shield of tunnel boring machine (TBM) Florence at Tantangara is continuing.

This technique, conducted by specialist contractors since 21 May, is working well, with a device mounted on the cutterhead directing a high-pressure water stream at the rock, which breaks apart and disintegrates.

We halted TBM Florence’s excavation of the Snowy 2.0 headrace tunnel in extremely hard and abrasive rock conditions on 16 May. Cutter disks on the edge of the cutterhead wore down very quickly and this, coupled with a curve in the tunnel, caused rock to pinch on the TBM’s shield.

We made the decision to stop tunnelling to ensure we did not damage TBM Florence.

The Snowy 2.0 project teams are monitoring progress of the rock removal so we can restart excavation.

We expect variable ground conditions to continue ahead of TBM Florence in the headrace tunnel, which will connect Tantangara Reservoir with the 2,200 megawatt Snowy 2.0 power station.

News

SNOWY 2.0 PROJECT UPDATE – MAY 2024

28/05/2024

In this month’s update, discover what it takes to support a huge construction operation like Snowy 2.0, as we build a 2,200 megawatt pumped hydro power station, more than 27 kilometres of waterway tunnels and other infrastructure.

While drill and blast activities, rock bolting and shotcreting continue underground, excavators work on the intakes and specialist crews operate the tunnel boring machines (TBMs), there are hundreds of people providing critically important support services.

Andrea Musacchio, Services Assurance Manager for Snowy 2.0, takes a look at what goes on behind the scenes of Snowy 2.0.

A major project component is managing truck and light vehicle logistics.

This includes thousands of road safety inspections annually, more than 260 bus trips taking workers to and from site each week and about 780 heavy vehicle movements, such as the distinctive segment trucks carrying locally manufactured tunnel lining segments for the TBMs.

The security team work at the gatehouse controlling site access and scan more than 6,000 people and 3,000 vehicles each week.

There are 20 heavy vehicle convoys a day at Lobs Hole, all managed by traffic controllers.

So far there have been more than 130 escorted loads of very large components delivered to site, some more than 7 metres wide. Few see these loads because they’re completed at night to minimise impact on the local communities and other road users.

The Snowy 2.0 General Services team of 190 people provide support functions that are vital to the day-to-day running of the project.

With a workforce of 3,000 people, many of whom are based onsite, the cleaners are kept busy with almost 2,000 room cleans a week.

And it’s not surprising that there’s 75 caterers – they’re cooking more than 36,000 meals a week. That’s 17,000 eggs, 900 kilos of bacon and 2 and a quarter tonnes of sliced watermelon, just for starters.

The General Services crew conduct repairs and preventative maintenance around the camp facilities and also provide a site bus service that completes around 1,500 trips a week.

Trainers and fitness instructors help organise sporting competitions and oversee thousands of gym visits every month, while the community team provides workforce engagement and communication. There are also hundreds of people in offices managing administration, invoicing and documentation, and organising meetings, rosters and site visits.

News

TBM FLORENCE UPDATE – 21 May

21/05/2024

With progress by tunnel boring machine (TBM) Florence in the headrace tunnel slowing in very hard and abrasive rock on Wednesday 15 May, the project ceased excavation by the TBM on Thursday 16 May due to rock pinching on the machine’s shield. This update on TBM operations was provided within 24 hours of the machine being stopped.

The Snowy 2.0 project team sought immediate advice from a specialist contractor with experience at other Australian projects with the same TBM situation. Today the contractor commenced work using high pressure water jets to remove the rock impinging on TBM Florence’s shield.

Timing for estimated recommencement of excavation will be determined on the successful removal of the rock.

The next TBM Florence update will be provided in the week commencing Monday 27 May.

News

TBM FLORENCE UPDATE

16/05/2024

Tunnel boring machine Florence has been ramping up excavating the Snowy 2.0 headrace tunnel, recently reaching 12 metres per day for a period.

With progress slowing in very hard rock on Wednesday 15 May, today (16 May) the Snowy 2.0 project team ceased excavation by the TBM due to rock pinching on the machine’s shield.

We are currently investigating the best way to relieve this pressure prior to recommencing excavation.

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