MARMC Divers, Engineers Ready USS John Warner for Deployment

NORFOLK (NNS) -- Mid-Atlantic Regional Maintenance Center (MARMC) Dive Team Bravo reinstalled a pinch roller assembly aboard attack submarine USS John Warner (SSN 785), pierside at Naval Station Norfolk, Oct. 20.

MARMC Alpha divers removed sections of the towed array handling equipment in September in order for MARMC engineers to inspect the equipment before being reinstalled.

"This is a new platform," said MARMC Dive Team Alpha Supervisor Luke Smart. "John Warner was commissioned a year ago, and it's been sitting idle in the water for a while now. We want to make sure that all components they have on board, especially the towed array handling system, work properly when they get underway soon."

Divers worked together to perform hull swipes one day earlier before MARMC Submarine Towed Systems Subject Matter Expert (SME)/Diver Sean McLaren and MARMC Dive Zone Manager Thomas Naab dove to perform production work.

"We pulled out a couple of things to let the engineers look at them, to see what kind of marine growth the submarine had encountered," said Smart. "We are ensuring nothing is broken, as well as performing regular maintenance to make sure the equipment won't break in the future. As long as everything looks good, it should operate properly."

Virginia-class submarines utilize the OA-9070E system, which uses electric motors for the capstan -- which turns the drive wheel -- and stowage drum assemblies, while Los Angeles-class submarines have the OA-9070B handling system which uses hydraulic motors.

"We removed the pinch roller assembly, consisting of two parts -- upper and lower," said McLaren. "The upper pinch rollers came out easy along with the upper bracket, but the lower pinch rollers were a little more difficult to remove, being that they are located under the drive wheel from the capstan. They were really heavily fouled, so we had to remove them and bring them back to our shop (MARMC Towed Systems Branch) for refurbishment. Our lead engineer, Ed Guidos, inspected them before we turned them over to our support contractor, Delphinus, to refurbish and completely rebuild them under Guidos' supervision."

John Warner's pinch rollers required more than a regular refurbishment because they are of the baseline design with no improvements or Engineering Change Instructions (ECIs) installed on the OA-9070E.

"This towed array handler system contains a pre-wrap reduction Capstan," said McLaren. "They've lowered the number of grooves in the drive wheel and the idler wheel, from three to two and two to one, respectively. That is supposed to change the stress that the system places on towed arrays, prolonging the life of the array. In order to remove the lower pinch rollers, we ended up having to cut a bolt off of the middle bracket, due to interference of the stop pin on one of the bolts on the middle bracket. With the new ECI design, there's no interference."

McLaren also ensured the electric motor's compensators levels were within specification, which indicates if it's full of oil. He and fellow divers took measurements of each piston, measurements of the caps on top of each piston, and the differential of where the pistons are supposed to be and where they actually are in relation to the compensator, using a temperature table in the maintenance standard.

"As we measured, we reviewed the maintenance standards to make sure everything was right," said McLaren. "The majority of our tasking was to inspect the system and to check the levels of the compensators on the motors, the bearings, and the electric inter locks."

The OA-9070E system is new to the Naval Station Norfolk port. McLaren has some experience working on this system, as part of an Alteration Installation Team (AIT), assisting in installing ECIs in dry dock, so he and fellow technicians and engineers are familiar with the system.

"This is the first time we've actually had one in our homeport that we can work on as part of the fleet," said McLaren.

Smart used the opportunity to cycle in some of his younger Navy divers on the team. Once Naab resurfaced, other divers took his place in order to gain the experience of working with this new system.

"My job as the SME for towed array systems is to go into the ballast tank with these guys (divers) and we work together to accomplish I-level maintenance tasks or planned maintenance requirements," said McLaren. "Part of my job, with the young Sailors, is on the job training to make sure they know what they are doing and to make sure everyone is following approved procedures."

McLaren serves as the technical advisor inside the ballast tank, while Smart has overall control of the dive.

"As a diver, I follow the dive supervisor's instructions," said McLaren. "Once we go inside the ballast tank, the team follows my lead. I'm glad that we all had the opportunity to go in there and work on it together."

Performing this inspection and removing equipment pierside saves the Navy money.

"Submarines are usually on a seven-year cycle for dry-docking, so within those seven years, anything that breaks underwater, we'll repair it," said Smart. "We can do anything underwater that they can do in dry dock."

John Warner is homeported in Norfolk and MARMC divers will be performing all future underwater maintenance.