Minnesota Power – Series Compensation Station

Project: Warroad River Series Compensation Station

Owner: Minnesota Power

Scope of Work: Minnesota Power’s (MP) Energy Forward Plan increased MP’s hydro power mix through a long-term agreement with Manitoba Hydro of Canada. To get additional power from Manitoba to Minnesota, MP installed a 500Kv transmission line that required construction of a new series compensation substation at the Minnesota-Canadian border. When it was constructed in 2019, this was the largest series compensation station in the world by capacity.

Lakehead was awarded a subcontract to provide the civil scope of work on this project. Our responsibilities included:

Forming and pouring more than 81 individual concrete foundations for lighting masts, bypass switches, disconnects, surge arrestors, ladders and pillars, as well as for the substation’s propane tank, generator, EEE building, storage building and breaker control cubicles. Highlights included: forming and pouring three 38’ x 79’x 1.5’ concrete capacitor footings; and installing three 8’ x 45’ dead end structure -drilled pier foundations, a ,165’ of 11’ tall by 8” thick ballistic wall with 2’ x 2’ grade beam, and sixteen 14’ deep by 2’-6” diameter drilled pier foundations. Other scope included:

• Excavation and backfill
• Final 4” stone / non-magnetic rock layer
• Cable trenches – over 1,000 lineal feet
• Electrical grounding grid – 10,150’ of 4/0 cable
• 3,000 lineal feet of underground conduit
• Internal 6’ chain link fence – 600’
• Material testing

Services: Project management, foundation earthwork, concrete, rebar installation, crane support and heavy lifting