TL 267 Newfoundland

Project Summary

Client

Newfoundland Hydro

Location

Bay d’Espoir to Western Avalon, NL

Length

188 km

Voltage

230kV HVac

Structure Type

Steel Lattice Suspension Tower Type A, B Steel Lattice Medium Angle Tower Type C Steel Lattice Dead-End Tower Type D, NDD, AA OPGW: 188 kms 48 single mode fibre, 278 kN RTS, 20.6mm diameter

Line Configuration

Conductor: 188 kms of 3 phase, single bundle, 804kcmil AACSR conductor OPGW: 188 kms 48 single mode fibre, 278 kN RTS, 20.6mm diameter

Foundation Types

Steel Grillage Foundation Type: A-1, B-1, C-1, D-1 (100 kPa Soil) Steel Grillage Foundation Type: A-2, B-2 (250 kPa Soil) Surface Rock Foundation C-3, D-3 Spread Footing Foundation Type AA-1, AA-3 Steel Lattice Dead-End Tower Type D, NDD, AA OPGW: 188 kms 48 single mode fibre, 278 kN RTS, 20.6mm diameter

Completion Period

November 2017

Project Sector

Transmission

PROJECT DESCRIPTION

Construction of 188km of 230kV HVac transmission line, TL 267, extending from Bay d’Espoir substation terminating at the Western Avalon substation. Proposed line parallels two transmission lines from Bay d’Espoir to Sunnyside on the Avalon Peninsula, and passes through the Bay Du Nord Wilderness Reserve. Rationale for the project is to ensure the continued stability and reliability of the Island Interconnected System particularly during faulting events and upgrade the infrastructure and power availability for the residents of Newfoundland.

SERVICES PROVIDED - PROJECT CHALLENGES

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SERVICES

Material Management services
Right of way preparation – approach and fit-for-purpose access construction (including installation of permanent bridges), environmental and construction matting
Survey and Staking of ROW boundary
Procurement, delivery and installation of mirco piles (We have procured but not installed)
Staking, assembly, and installation of grillage and surface rock foundations
Installation of In-Line Grouted Anchors for guy wires
Structure assembly & conventional tower erection by mobile land crane
Structure erection by heli-crane
Tension stringing of 3 phase single bundle conductor, OHSW, and OPGW
Implosion splicing and dead-ending

CHALLENGES

Species at risk, bio-diversity and bio-security land use restrictions
Construction of line through Wilderness Reserve with tight environmental restrictions
Extreme weather conditions – temperatures down to -40 C (-55 C with wind chills), strong winds, heavy snowfall, winter storms
Extreme soil conditions – long sections of deep bog
Existing energized lines, water bodies, & highway crossings