A majority of the water based work is effected by tide cycles. Continuous, extensive planning is executed to ensure tides permit the proper draft for boats and barges for certain tasks and activities. Each missed opportunity could cause a 24-hour project delay.
Stringent environmental laws limit in-water work to 4 months (Sept-Dec) out of the year.
The new land-based towers are in environmentally protected areas. Extensive action must be taken at each location to ensure the locations remain undisturbed. This action includes the installation of environmental matting, silt socks, silt fence, daily inspections, etc.
Due to stringent environmental laws which limit in-water work to September-December each year, a consolidated effort was made to install all required cofferdams and work platforms so that work could continue beyond the in-water work restrictions. Once all cofferdams were installed, the new tower locations were excavated and stoned. Currently pipe piles are being driven to support the new towers. Those piles are being cut off to the proper elevations, pile rebar cages are being installed, and piles are being filled with concrete.
For the water-based towers, future work includes installing the rebar, forming the foundations, and pouring the foundations. The land-based towers will be drilled for excavation, rebar installed, and concrete poured. Once all foundations are prepared, the new towers will be installed. The owner will take an outage on the transmission system, and the new conductor will be installed and tied-in. The existing conductor, towers, and foundations will be demolished.