Cianbro Irby has reached another significant milestone for the MPRP Central Loop Project by safely completing the Section 375/375T transmission line rebuild. This 345 kilovolt (kV) rebuild is a temporary work-around in preparation for the future Surowiec substation expansion. An existing portion of line for this section was directly in the path of the substation expansion footprint. Cianbro Irby's scope of work involved the installation and demolition of both temporary and permanent structures to reroute the electrical current so there is no interruption in power during the substation expansion project. The temporary structures for 375T will be demolished once the substation expansion is complete. The newly installed 375 structures will remain and lines will hook directly back into the substation.
To say this section of transmission line work was challenging would be an understatement. Obstacles presented themselves from every angle in this one area of rural Pownal, Maine. Surowiec substation is the hub for nine other intersecting transmission lines. Adding to the challenges were the energized distribution lines running through the work area and the Joint Venture sharing a workspace with Hawkeye, contractors for the MPRP Southern Loop Project.
The Southern Loop's scope of work ends at Surowiec, where Cianbro Irby's scope begins. This situation made for a dangerous and very congested work zone. Section 375 Line Engineer, Matt Gale, placed emphasis on the importance of constant communication and coordination among contractors to make sure that team members were safe and that the work being performed was efficient and uninterrupted.
Three weeks of matting and access work took place in preparation for the outage. During this outage, 40 team members worked 14 hour days, 7 days a week to complete the work within the 19-day window. During this time, Mother Nature dropped 6.5 inches of rain, creating hazardous conditions for walking and for maneuvering equipment on timber mats. An added challenge was that the work area was located primarily in wetlands, which meant that storing and refueling equipment was impossible within 100 feet of the sensitive terrain. Equipment had to be relocated to an environmentally safe location over night and moved back in the morning to comply with stringent restrictions from the Maine Department of Environmental Protection.
Another unique challenge for the joint venture involved the demolition of the old 375 structures which included salvaging the conductor to reuse on the new permanent 375 structures. The conductor had to be carefully cut, rolled around a reel using the puller/tensioner and redistributed on the new structures. The conductor would be rendered worthless if bent or scuffed in any way. The attention to detail and the constant radio communication maintained by team members during this process was top notch.
Currently crews are working in the same vicinity on their next scheduled outages for Sections 62 and 64, a 115 kV rebuild, with a planned completion by the end of November.