Location: Cutler, Maine
Triton Marine contracted with the U.S. Navy to supply full mission 15 MW capacity power to the mission critical Naval Computer and Telecommunications Station by way of installing a dedicated submarine cable interconnected directly to the local 115 kV substation. Scope included maintaining the existing diesel power plant to provide a backup supply of power to the VLF site by way of upgrading the existing 1950’s 4.16 KV switchgear and integrating it into the new substation and SCADA system.
To interconnect the local substation to the Cutler Power Plant, nearly 7 miles 34.5kV subsea power transmission cable was trenched 3 meters into the seafloor across Machias bay in early winter months. Prior to cable installation a marine hazard and route clearance survey were completed to ensure successful cable placement. Due to the nature of trenched subsea cable, cable lay operations were maintained 24-hours a day for 20 days.
The subsea cable upland transition required threading 1,200ft of cable into a custom anchoring device installed 30ft underwater and then cautiously pulling the cable trough 1,000ft of 10-inch horizontal directional drilled and steel cased wireway to terminate in new upland electrical vaults at both ends.
To support the power interconnect a new power distribution system, comprised of 34.5kv Switchgear, 5kv Interior Switchgear, (2) Power Transformers, was installed with all the typical supporting appurtenances. Primary Challenges included installing and integrating the new system into existing 1950’s diesel powered power station. The existing building required modifications to provide space for modern switchgear and the SCADA system required custom programing to enable communications with the existing backup generator power system.
Project Tasks:
- CIP Concrete
- Subsea Cable Lay
- Diving
- HDD
- Earthwork
- Landscaping
- Electrical