When the Hawaiian Electric Co. Inc. (HECO; Honolulu, Hawaii, U.S.) was awarded the US$22 million contract to install a substation and underwater power line connections for the U.S. Navy's planned comprehensive redevelopment of historic Ford Island, a mile away from Oahu across historic Pearl Harbor, it was obvious that a lot of things were going to have to happen in close sequence and within very tight parameters.

First of all, the mile-long 46-kV cable pull 30 ft (9 m) below the seabed and 70 ft (21 m) below sea level would have to avoid the submerged historic battlewagons Arizona and Nevada that still lie on the harbor's bottom.

HECO awarded the general contract for the cable pull to Hawaiian Dredging Construction Co. (Honolulu) and brought in American Electric Co., LLC (Honolulu) as the electrical subcontractor.

The connection would consist of twin parallel 24-inch(61-cm) steel casings containing HDPE ducts for the cable and additional ducts for fiber optics and ground wire.

Critical to the pulling operation was finding and using the appropriate equipment for a cable pull that would be stretching recognized limits of product and technology. The electrical subcontractor chose to requisition three pieces of customized gear. Two were provided by HisBusiness Inc. (Laguna Beach, California, U.S.). The first was a series of roller devices mounted on a flatbed truck that would guide the cable off the reel and down into the manhole where the casing ended. Then a second motorized variable-speed drive roller unit was designed to spin the reel and feed the cable off as it was being pulled.

Third, for the lubrication process, a foot-actuated device called the SoaperMonkey, manufactured by WLD, LLC (Manchester, New Hampshire, U.S.), which pumps lube directly from a standard 5-gal (19-liter) bucket into a split fitting that wraps around the cable, ensuring an even application and requiring only one operator. The unit was re-engineered and upsized to work from a 55-gal (208-liter) drum to accommodate the amount of lube needed to meet the calculated speed of the pull.

There were 24 pulls in all, culminating in February, and the lines were energized before the early March “power on” deadline set by HECO.

The lines under Pearl Harbor will service all power needs for both existing structures, an additional 2000 new housing units being built at a cost of $84 million for civilian and military personnel, as well as a complex of aviation, naval and meteorological museums including the $240 million Pacific Regional Center of the National Oceanic and Atmospheric Administration.

Note: Transmission & Distrbution World will publish an in-depth article on this project in an upcoming issue.