FIBER OPTIC & POWER, UNDERWATER CONSTRUCTION

POINT LOMA, CA

PROJECT DETAILS

Work included the upgrade to the existing Type V Underwater Magnetic Measurement System (UMMS) located in San Diego, California, to a new Type VI Underwater Electro-Magnetic Measurement System (UMMS) in support of Commander, Pacific Fleet requirements. The new installation required the routing of cables between the junction box platform and the sensor array inside an excavated trench and the backfilling of all trenches and other excavations with non-magnetic gravel.

SHORELINE PROTECTION

Pendleton, CA

PROJECT DETAILS

Precon Marine was contracted to fabricate and place the Large Organism Exclusion Devices (LOEDs) at the San Onofre Nuclear Generating Station in California.

This project required exacting measurements, both sub-aqueous and topside, to successfully complete.

UNDERWATER CONSTRUCTION

NAVAL BASE CORONADO/SSTC, SAN DIEGO- AIMS REFURBISHMENT

PROJECT DETAILS

This project involved constructing, transporting, and installing a precast concrete caisson over the existing FRP piles and positioning the caisson structure on the seafloor. The caisson was constructed using low magnetic permeability concrete and fiberglass reinforcing. A stone leveling base, consisting of clean washed cobbles, shall be installed prior to the concrete caisson being lowered into the water. Eight concrete pipe sleeves shall be lowered over the existing piles and grouted in place using non-shrink cementitious grout. The caisson shall be filled with cobblestones, followed by the placement of a precast concrete cap on top of the concrete caisson. The concrete cap shall be secured in position by dowels and grout. Scour mats shall be installed in places around the perimeter of the structure to prevent undermining. Fiberglass cable raceways shall be installed on the 3 scour mats, caisson, and pipe sleeve, followed by the installation of the government-furnished junction box, sensors, and sensor cables. Upon completion of the caisson, pipe sleeve, scour mat, and sensor installation, the Navy will conduct tests and validate the sensor array.