Phoenix Performs Thruster Change-out and ABS In-water Survey for U.S. Missile Defense Agency

The Sea Based X-Band Radar (SBX-1) a floating, self-propelled missile tracking system operated by the U.S. Missile Defense Agency consists of an X-band radar array mounted on a 50,000 ton twin-hull semi-submersible. SBX-1 uses four azimuthing thrusters for propulsion and positioning and the requirement to change-out the forward-starboard thruster waterborne fell to Phoenix International. Working closely with thruster OEM Wärtsilä Defense, the Phoenix team of divers and technicians installed a unique underwater hydraulic trolley system to allow the 25-ton thruster to be moved outboard of the thruster well once separation from the steering pipe was complete. This innovation was required because the semi-sub deck overhang coupled with a shallow Pearl Harbor repair berth precluded a direct yard-and-stay procedure. The Phoenix team was able to remove the existing thruster and, reversing this process, install a rebuilt thruster all within the tight timeline stipulated by the ultimate client. As the thruster work commenced, our client asked if Phoenix could also prepare SBX-1 for and perform an ABS in-water survey (IWS) in parallel with the thruster change-out. Our Pearl City location and Hawaii based team allowed us to answer in the affirmative and we went to work immediately performing waterborne hull cleaning, shell-plate thickness gauging, sea-chest blanking, and visual inspection with an ABS surveyor in attendance. During the inspection our divers discovered fishing net inside the aft-port thruster. They subsequently removed the rope guard, cut away all netting, inspected the thruster seals and re-installed the rope guard. All pre-inspection, inspection and repair work was conducted while the thruster change-out was in-process.

Phoenix’s ability to marshal engineering, diving and technical expertise from multiple offices, coupled with our presence in Hawaii enabled us to satisfy several client requirements simultaneously, thereby returning a key national asset to full operational status in the shortest feasible time.

About Phoenix
Phoenix is an employee-owned, ISO 9001-2008 Management System certified marine services contractor providing manned and unmanned underwater solutions, design, engineering, and project management services to a diverse set of clients worldwide. Expertise is available from seven regional offices in the areas of wet and dry hyperbaric welding, Nondestructive Testing (NDT), subsea engineering, conventional and atmospheric diving, Autonomous Underwater Vehicle (AUV) and Remotely Operated Vehicle (ROV) operation. Our capabilities include underwater inspection, maintenance, and repair of ships, platforms and structures; deep ocean survey, search and recovery; submarine rescue; subsea construction, tieback, plug and abandonment; underwater mining, archaeological, and documentary projects.


Location: Hawaii, USA