2004 Submarine Cable Project
This article on OPALCO’s 2004 Submarine Cable Project was written by Engineering Administration Specialist Marcia Gillingham. Marcia, who began working at OPALCO in 1997, is the contract administrator and accountant for the project.
OPALCO’s
2004 Submarine Cable Project, which is now in full swing under the supervision
of Project Manager, Terry Turner and Manager of Engineering, Mark Tilstra, actually
began two and a half years ago with the permit and planning process. It is currently
in the marine construction phase, which includes the installation of four new
submarine cables (two composite 69 kV, 350 MCM copper conductor with an
embedded 48 strand
fiber optic cable, and two 48 strand fiber optic, single armor submarine cables).
You may refer to OPALCO’s 2004 Annual Report for more detail on this project.
Caldwell Marine International, Inc. (CMI) of Toms River, New Jersey was the successful bidder on the project and is now fully mobilized and operational.
The utmost importance and care is being paid to the environmental issues of the project. Marine surveyors and biologists and an archaeologist were consulted at length during the planning process and will be on site at defined sensitive areas throughout cable installation. Different installation techniques will be implemented in each crossing to impact each unique area as little as possible.
Preparing the sites for the new cables involved a lot of work. During the week of August 23rd, Armadillo Underground, Inc. of Salem, Oregon successfully completed the installation of two 150 foot runs of steel duct through the steep slope on the south end of Blakely. The 10 inch diameter steel pipe was directionally drilled under the cliff in 10 foot sections and welded together piece by piece. These two ducts will accommodate the new composite cable and a future 69 kV cable installation. OPALCO crews and many local contractors were involved with the installation of concrete vaults that will anchor the cables on the shore end.
This project also included the removal of two obsolete 25 kV cables on September 12-15, when CMI picked up a failed 25 kV cable between Decatur and Blakely (which will be taken to Seattle and scrapped), and a 25 kV cable between Shaw and Orcas (which will be warehoused at OPALCO for future distribution use).
 |
CMI barge at Orcas Landing on September 16, 2004: far left is the reel of cable that will be taken to Seattle and scrapped. The reel just behind the workers in hard hats is the 48 strand fiber optic cable recently installed in the Shaw-Orcas crossing. The largest reel contains the salvaged 25kV cable, and the remaining smaller reel in the back is the new fiber optics cable for the Shaw- Lopez crossing. |
The Orcas Landing was alive with activity on September 16th with the start of the installation of the first fiber optic cable for the 4,275 foot Shaw to Orcas, Harney Channel crossing. Using advanced technology, OPALCO crews pulled the cable from the barge up 800’ of installed duct on the Orcas Hill slope to the termination site. After testing by the marine biologist to assure that the shore was free of evidence of spawning activity, a low impact plow technique was used for approximately 70 feet at the shoreline to protect the eelgrass habitat. Due to excellent planning and coordination on the part of OPALCO and CMI, all went extremely well and without a single hitch.
The second fiber optic cable was installed in the 6,500 foot Lopez to Shaw crossing in Upright Channel. Upon completion of the fiber cable lays, CMI will then head to Seattle where they will load 11,000’ of composite electric cable and retool the barge for installation of that much larger cable.
The final phase of the project is the installation of the 37 pound-per-foot composite cable; a bottom surface lay will be used in the 6,425 foot crossing from north Blakely Island to Deer Point on Orcas, and a jet-plow method will be used in the 4,000 foot crossing in Thatcher Pass from north Decatur to south Blakely where it will be pulled up into one of the steel ducts to the termination site.
The installation of these two composite power cables is an essential part of OPALCO’s plan to convert the entire transmission system from 25 kV to 69 kV in the future. The installation of the two fiber optic cables, along with the fiber in the composite cables, is for OPALCO’s intercommunications network and fiber optics backbone project.
