Naval Facilities Engineering and Expeditionary Warfare Center (NAVFAC EXWC) Ocean Facilities Department completed the reinstallation of four fleet moorings in Outer Apra Harbor at Commander, U.S. Naval Forces Marianas (COMNAVMAR) in late December of 2020.
For background, fleet moorings increase the effective berthing space at naval facilities, are ideal for prepositioned vessels and training exercises, and can be the preferred berths for a variety of vessel types in heavy weather.
NAVFAC EXWC manages the U.S. Navy Fleet Moorings Program that supports naval facilities by providing alternative methods to secure vessels from piers and wharfs by utilizing anchored buoys.
In 2010, the four reinstalled fleet moorings in Outer Apra Harbor were placed in wet storage at water depths of 100 feet. NAVFAC EXWC called upon U.S. Navy Underwater Construction Team (UCT) 2 divers to cut the chain and rigged components to surface buoys for future recovery using crane barges.
Beginning in 2018 through 2019, NAVFAC EXWC recovered and reinstalled three of the four fleet moorings at COMNAVMAR. Unfortunately, professionals were unable to successfully recover the fourth mooring due to the mooring’s sinker (a concrete weight that helps maintain positioning) deep embedment in the mud. The operation was temporarily aborted in September 2019 until stronger rigging components could be installed.
In December of 2020, UCT divers installed a high-strength, lightweight AmSteel® pennant to the riser chain connected to the buried sinker of the fourth mooring, and reinstalled a new rigging assembly on an anchor leg, both connected to small buoys on the surface.
In conjunction with NAVAC EXWC, Oceanetics℠—an engineering, fabrication and field support specialist company—served as the prime Federal Government contractor for the fleet mooring installation, which mobilized a crane barge for repair operations after UCT completed the rigging. While onsite—with a new plan and increased capacity equipment—the troublesome mooring sinker broke free from the mud. It took 16 hours to safely manipulate all the components on the deck. Worn materials were replaced, anchor legs were reconnected, and a new buoy was added all while the new mooring was successfully reinstalled. During the project, NAVFAC EXWC and Oceanetics professionals also replaced the buoy on another mooring that USNS 2nd Lt. John P. Bobo uses—the lead ship of a line of maritime prepositioning force vessels.
The successful execution of the four fleet mooring repairs in Outer Apra Harbor have enabled the continued use of the fleet moorings for the lead Military Sealift Command preposition ships, and other various uses by port operations. Port operations are now mission ready, and meet the warfighter requirements for permanent and transient fleet forces in theater.
About Naval Facilities Engineering Systems Command, Engineering and Expeditionary Warfare Center (NAVFAC EXWC):
NAVFAC EXWC is a command of more than 1,300 dedicated federal employees, contractors, and military personnel who provide science, research, development, testing, evaluation, specialized engineering, and mobile logistics capabilities to deliver sustainable facility and pragmatic expeditionary solutions to the warfighter.