USS Nimitz Reaches One Year in Yards

USS Nimitz (CVN 68) marked one year since it officially began its docking planned incremental availability (DPIA) at Puget Sound Naval Shipyard and Intermediate Maintenance Facility (PSNS & IMF) in Bremerton, Wash., Jan. 11.

Nimitz entered dry dock DPIA Jan. 11, 2011. During the past year, Nimitz has been busy working alongside PSNS & IMF workers to install and replace vital systems on the ship to keep them operational. The maintenance done while in the shipyard and following months will enable Nimitz to fully perform their duties at sea.

The work began at a meeting 24 months before the scheduled DPIA when officials met to discuss primary overhaul plans. After reviewing an extensive checklist, the team began making official preparations 18 months prior to the shipyard period. These preparations included figuring out what needed to be done and scheduling it to fit in the allotted time.

During the maintenance period, the ship went in and out of dry dock to remove and overhaul both rudders as well as work on the propellers. Workers also replaced some main shafting; installed new sleeving on the sea chest; inspected and preserved numerous tanks, voids, and JP5 fuel tanks; overhauled forward and aft refrigeration plants; and preserved the hull and other areas around the catwalks.

While this work was being done primarily by PSNS & IMF civilian workers, with the help of Sailors here and there, ship’s company also spent the shipyard period overhauling a lot of their spaces. Sailors gutted out and rebuilt 30 berthing spaces, tiled and resurfaced hundreds of decks, and repainted hundreds of spaces. Altogether ship’s force, PSNS & IMF personnel and contractors logged almost 700,000 man-days worth of work costing over $260 million dollars.

“Obviously you have to work as a cohesive team to complete that amount of work,” said John Simpson, project engineering planning manager for Nimitz’ 2011 DPIA. “The ship’s crew was an integral part of that.”

Ship’s crew and PSNS & IMF workers have been working especially hard to take complete advantage of the DPIA. During the past year, they have completed even more work than what was originally planned and scheduled.

“I am extremely proud of the work that has been accomplished,” said Lt. Cmdr. Charles Jones, ship’s maintenance manager. “We did 25 to 40 percent more work than expected. The work that was completed between Puget Sound Naval Shipyard [and Intermediate Maintenance Facility] and Nimitz ship’s force will help us get to the end of ship’s life.”

Today’s carriers are designed with a 50-year life span but some significant maintenance is required at specific intervals during the ship’s life. Most of the work done this past year falls under this preventive maintenance. Other maintenance includes updates to weapons systems to increase security on board.

Dry-dock availabilities like the one Nimitz recently completed are less frequent. This was Nimitz’ first dry-dock availability in 12 years.

“This was the first Nimitz class carrier to go 12 years between dry dock availabilities as opposed to the original six to nine years,” said Simpson.

Now that Nimitz is done with its scheduled maintenance the crew is busy testing systems and preparing for what lays ahead in dock and sea trials.

“Ship’s force is at its end of the maintenance period,” said Jones. “Shipyard personnel are still working on the weapon system and contractors are putting in new laundry appliances. That’s the last of our production work.”

With the end of production work comes the task of firing up new and recently unused systems.

“We are still bringing systems out of lay-up and firing systems that aren’t working properly,” said Jones. “We still have testing to do during dock trials. Whatever we don’t get done during dock trials, we will get done while we are out to sea.”

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Naval Today Staff , January 13, 2012