NOVI – ITC Holdings Corp. said its ITCTransmission subsidiary had placed in service Phase 1 of its 140-mile Thumb Loop high voltage transmission line, capable of supporting a maximum capacity of about 5,000 megawatts.

Phase I is 62 miles of double-circuit, 345,000-volt lines from the new Bauer substation in Tuscola County to the new Rapson substation in Huron County.

ITC says the Thumb Loop will serve as the backbone of a system designed to meet the identified maximum wind energy potential of the Thumb region.

?Putting Phase 1 of the Thumb Loop project into service on time and on budget is a testament to ITC?s independent transmission model,? said Gregory Ioanidis, president of ITC Michigan. ?This project will strengthen the transmission grid in the Thumb area of Michigan and also will serve as a backbone for the interconnection of new generation sources in the area. It will increase transmission system capacity and reliability, enable the delivery of lower cost generation and provide more efficient transmission of energy.?

During the construction phase, ITC estimates that the entire Thumb Loop project will have a direct impact of $366 million to the Michigan economy, including jobs with local contractors, vendors and suppliers. The area economy benefits from the demand for supplies and services such as concrete, hardware, fuel, gravel and trucking, as well as food, lodging and other personal needs for construction crews.

Work is proceeding on schedule for the remaining segments of the Thumb Loop project. All poles have been erected and the conductors are being installed along the 20-mile Phase 2 section in St. Clair County. Construction on Phase 3 from the Rapson substation in Huron County through Sanilac County to the Greenwood substation in St. Clair County will get underway in the first quarter of 2014. The entire project will be completed and in service in 2015.

The Thumb Loop will consist of 3,640 miles of wire, 786 steel monopole towers and , 30 of the more traditional ?Erector set? steel lattice towers. The towers are between 800 and 1,100 feet apart and are 130 to 180 feet high.