TRANSGRID - 1611 MARAGLE 330KV SWITCHING STATIONAND 330KV TRANSMISSION LINE CONNECTIONS REV1.2

2. Project OverviewProject Interface Parties & Nominated Parties

• Maragle from Sydney• 509km (5h, 39mins)

• Maragle from Tumut• 87km (1h, 10mins)

Item Detail

Client TransGrid (owned by Spark Infrastructure Consortium on a 99 year lease)

End Client Snowy Hydro (owned by the Australian Govt.)

Key Subcontracts

Switching Station• Civil & Foundations Contractor• Building supplierTransmission line• Clearing and access Contractor• Steel supplier

Refer to Section 05 Procurement

Key Dates Contract award – 21 October 2020POS – 14 January 2022Practical Completion – 26 March 2024

Location Located 509km Southwest of Sydney in Maragle, NSW

2. Project OverviewLocation Map

Western side of Tumut River

Eastern side of Tumut River

Lobs Hole

Tumburumba30mins

Snowy Accommodation Camp

2. Project Overview – 330kV Switching StationScope of Works

The scope of works includes the Design, Supply, Construct, Testing and Commissioning of a new 330kV Switching Station.

Detailed Descriptiona) Bulk earthworks suitable for construction and laydown areas for the Maragle switching station

construction and a separate laydown area for the transmission line work;b) Communication equipment within the Maragle substation and the remote substations (Upper Tumut and

Lower Tumut Substations) to link the Snowy 2.0 Project and the Maragle Substation to the network. c) Delivery to Site, erection and site acceptance testing (SAT) of the HV equipment supplied under Section

1.14;d) Furnishing and cleaning (until the date of Practical Completion) of the new 330kV secondary systems

building;e) Secondary systems (including communications, protection, metering and control systems) in the new

Maragle 330kV switching station;f) Permanent access road linking Elliot Way to Maragle switching station. The access road spur to the future

500kV substation shall be constructed under a separate contract.g) All testing and commissioning including but not limited to factory acceptance testing (FAT), SCADA

acceptance testing, site acceptance testing (SAT) and commissioning of the new 330kV switching station;h) All studies necessary to inform the design and construction of the Maragle substation including weather

impacts and elevation of the Site;i) Remote end protection, control, automation and communication Works of line 64 located at remote end

substations (Upper Tumut and Lower Tumut Substations).

• *Energisation to be completed by TransGrid

2. Project Overview – 330kV Transmission LineScope of Works

The scope of works includes the Design, Supply, Construct, Testing and Commissioning of two new double circuit 330kV transmission lines from Customer cable yard to the new Maragle switching station and OPGW/OHEW upgrade, cut into Line-64 and connection to the new switching station.

Detailed Descriptiona) New or upgrade of existing access tracks, including the need for water crossings, as required for the construction and

maintenance of the new 330kV transmission lines, cut into Line 64 at Structure 43, and the installation of OPGW on Line 64;b) Clearing and disposal to form the 120m wide easement required for the new 330kV transmission lines. The easement must be

cleared in accordance with the Transmission Connection EIS determination once receivedc) Ancillary provisions, including brake and winch sites, crane pads, site compounds and equipment laydown areas;d) Two double circuit 330kV transmission lines to connect the new Maragle switching station to the Snowy 2.0 cable yard in Lob’s

Hole Ravine area. Design for all critical load cases, including snow and ice loading and vibration control. Prototype assembly and fabrication drawings are required for all tower types. Full scale load testing to destruction will be required for possibly (to be determined) two types;

e) Double circuit 330kV transmission line with OPGW connecting the new Maragle switching station cut into Line 64. Design of the new double circuit line for all critical load cases, including snow and ice loading;

f) New OPGW and earthwire on Line 64 between structures 21 and 69, approximately 19km. The work includes any tower earth peak and body strengthening required;

g) Disposal of all redundant transmission line items;h) All studies necessary to inform the design and construction of the transmission lines including weather impacts and elevation

along the length of the transmission lines;