Project Overview
132kV overhead power line to Liqhobong Substation, 132kV feeder bay and 132kV Capacitor Bank at the Lejone Substation, 2 x 20 MVA 132/11kV Substation, 2 x 11kV lines to Kao and 2 x 11kV lines to Liqhobong.
- 30 km,132kV Wolf conductor on Lattice Towers.
- 30 km of 24 fiber OPGW and earth conductor on above towers.
- 1 x 132kV Feeder Bay and Capacitor bank at Ha Lejone Substation.
- Liqhobong 132/11kV Substation with 2 x 20MVA Transformers and 132kV Incomer bay.
- Two 6.7km Wooden H-pole Structure 11kV Wolf lines to Kao Mine.
- Two 1.5km Wooden H-pole Structure 11kV Wolf lines to Liqhobong Mine.
Project Detail
Work at LEC's existing Ha Lejone 132/66/11 kV Substation
The works at Ha Lejone was to provide a second 132 kV feeder bay and 132kV Capacitor Bank and consisted of :
- Extensions to the substation yard and security fence as required.
- Extensions to the earthing mat and earthing of all new equipment.
- All concrete and building work required for foundations, trenches, etc.
- All new steel support structures.
- New primary electrical equipment for a 132 kV feeder bay.
- New primary electrical equipment for a 132kV capacitor bank.
- AC and DC supplies, protection, control and supervisory equipment and control cabling.
- Herbicide and yard stoning.
- Testing, commissioning and handing over to the Employer of the completed works.
- Attendance during the one year defects liability period.
Work at the new 132/11kV Liqhobong Substation
The work required at Liqhobong was to provide a new 132/11kV substation with a 132kV feeder, 2 x 20MVA 132/11kV transformer capacity,11kV switchboard and 11kV lines to Liqhobong Mine. This work consisted of :
- All earth works required for the substation platform for the new 132 kV yard, transformer bays and building.
- New access roads and drainage to the substation.
- New earth mat, as well as the earthing of all equipment.
- New security fence.
- All concrete and building work required for kerbs, plinths, foundations, runways, control buildings, cable trenches, etc.
- All steel support structures required to house primary equipment and support power lines.
- All new primary electrical equipment.
- AC and DC supplies, protection, control and supervisory equipment and control cables.
- Herbicide and yard stoning.
- Testing and commissioning and handing over to the Employer of the completed works.
- Attendance during the one year defects liability period.
Work on the Ha Lejone / Liqhobong 132 kV Overhead Line
This line was constructed between the existing Ha Lejone and the new Liqhobong Substations. This single circuit 132 kV overhead line consists of the following:
- The survey of the line route and subsequent design profiling and templating.
- Environmental impact assessment, including obtaining approvals from all stakeholders.
- Negotiations with all affected land owners, including the payment of compensation where required, to obtain written approval for the crossing of, and/or the erection of structures on land occupied by them.
- All lattice structures required to support the new overhead line.
- Foundations and anchors required to support structures.
- The earthing of all structures.
- ACSR "Wolf" conductor, overhead earth wire and optic fibre cable.
- Completion of closing spans and communication equipment at the two substations.
- Testing, commissioning and handing over to the Employer of the completed works.
- Attendance during the one year defects liability period.
Work on the Liqhobong/Mine 11kV Overhead Lines
These lines were provided between the new Liqhobong substation and the new Liqhobong Consumer Substation. These two single circuit 11 kV overhead lines consisted of the following:
- The survey of the line routes and subsequent design profiling and templating.
- Negotiations with all affected land owners, including the payment of compensation where required, to obtain written approval for the crossing of, and/or the erection of structures on land occupied by them.
- All wood structures required to support the new overhead lines.
- Foundations and anchors required to support structures.
- The bonding of all wood structures.
- ACSR "Wolf" conductor, overhead earth wire and optic fibre cable.
- Completion of closing spans and communication equipment at the two stations.
- Testing, commissioning and handing over to the Employer of the completed works.
- Attendance during the one year defects liability period.
Work on the Kao/Mine 11kV Overhead Lines
These lines were provided between the new Liqhobong substation and Kao Consumer Substation. These two single circuit 11 kV overhead lines consisted of the following:
- The survey of the line routes and subsequent design profiling and templating.
- Negotiations with all affected land owners, including the payment of compensation where required, to obtain written approval for the crossing of, and/or the erection of structures on land occupied by them.
- All wood structures required to support the new overhead lines.
- Foundations and anchors required to support structures.
- The bonding of all wood structures.
- ACSR "Wolf" conductor, overhead earth wire and optic fibre cable.
- Completion of closing spans and communication equipment at the two stations.
- Testing, commissioning and handing over to the Employer of the completed works.
- Attendance during the one year defects liability period.
Project Motivation:
Liqhobong Mine required electricity for their new plant and infrastructure. Kao Mine upgraded from Generator Power to Electricity.
Project Features:
Infrastructure Projects obtained a concession for the extension of the electrical network to the Kaonyana Area. This equipment and work required for their new 132kV overhead power line to Liqhobong Substation, new 132kV feeder bay and 132kV Capacitor Bank at the Lejone Substation and new Liqhobong 2 x 20 MVA 132/11kV Substation.
Environmental Considerations:
All steps were taken to insure that the environmental impact of the new power line was minimized. The appointment of a local qualified specialist firm with experience of performing this type of study in Lesotho. The firm appointed started with investigations and a scoping report, in accordance with existing legislation and the requirements of the relevant Government Departments. The line route, type of construction, positioning of towers, etc. were adjusted and altered as required to minimize the environmental impact and to assist in obtaining a final approved environmental record of decision. All necessary rehabilitation to structure positions, as defined in the record of decision, was performed.
In general, the environmental process was as follows:
- Detailed investigation and discussions with all stakeholders, including all relevant departments.
- Conducted a full public participation process and obtained acceptance.
- Request revisions to line route, tower siting, etc. as required to minimize the environmental impact.
- Additional investigations, discussions and further public participation.
- EIA report and approval thereof from all relevant stakeholders.
- Implementation of the environmental management plan during construction.
Negotiations with the residents involved, both where structures were erected on their property, or where access roads crossed agricultural fields. Acceptable compensation was negotiated with the affected land owners and a record of all way leave negotiations with positive identification of the properties and people concerned, together with the written approvals and a record of compensation paid.
Specifications:
Specifications for the civil works:
- SANS 0100 Structural use of concrete
- SANS 0162 Structural use of steel work
- SANS 0163 Structural use of timber
- SANS 0164 Code of Practice for use of machinery
- SANS 1200 Standard specification for Civil Engineering Construction
- TRH14 Guidelines for road construction material
"Model Preambles for Trades" (1995 Edition) as published by the South African Association of Quantity Surveyors.
Specifications for the Electrical works:
- IEC 60185 Current transformers
- IEC 60044 Instrument transformers
- SANS 1339 MVXLPE cable
- SANS 0164 Code of Practice for use of machinery
- SANS 150 LV cable
- SANS 763 Hot-dip zinc coatings
Project Special Characteristics:
Highlight any special construction technique that would differentiate this project and LSP skills above the run of the mill.
- Construction in Mountainous Area
- IEC 60044 Instrument transformers
- 85% Rock Excavations
- Long spans over valleys
- Tension stringing
