The Dry Dock 12 pipe field for John F. Kennedy (CVN 79) holds as many as 17,000 pipe components.
“WHEN WE STARTED OUT LOOKING AT HOW WE WOULD BUILD THE SHIP TWENTY PERCENT CHEAPER - WHICH IS AN UNPRECEDENTED CHALLENGE IN SHIPBUILDING – WE REALIZED THAT WE’D HAVE TO DO THINGS VERY DIFFERENTLY.”
Photo by Chris Oxley courtesy of HHI.
do this, we’d have done it long ago,” he assured. “Tere are a lot of technical challenges—from where you put the structural erection breaks to how you minimize the use of temporary structure to make some of these heavy lifts. So we’re doing a lot of pre-fitting.” Essentially, the Newport team is building structural boxes called units. Tey take the units and put them together to build larger sections of the ship they call superlifts—which they then erect into the dry dock. Traditionally, a ship would be fit-built in the dry dock and the outfitting would be added as they go. Builders would do a lot of the outfitting (piping, electrical, even painting) much later in the build cycle. On CVN 79 (and CVN 78 to an extent) the Newport team has done a lot more outfitting of those sections of the ship before they put them in dry dock. “So, while the superlift is still sitting up on a land-level facility—a fabrication area—we’re putting in a lot of the major equipment—piping, pumps and motors and valves, and in some cases, insulation and paint—before it ever goes into the dock,” explained Butler. “Because once you put that section of structure in the dock, it becomes much more costly to work within because of material handling, confinement of spaces, those types of things. So, as Geoff was saying, our real driver is pre-outfitting those sections—before they go into dock and become part of the overall ship structure.” In some cases on CVN 79, the team is erecting superlifts
in a very high state of completion, where the only thing left to do once they get in dock, is basically the final electrical, some valves, and then insulation and paint. Ultimately, the turn-key operation will take 11 years for
the Kennedy, which isn’t abnormal for this type of a build, but the Newport team is already seeing avenues of opportunity in regards to trimming down that lead time—as a result of advanced modular construction techniques. “When you look at it from the perspective of the Nimitz- class carriers all the way through Ford, and then Kennedy, and ultimately CVN 80, we’re constantly evolving and improving
and maximizing the whole ship construction cycle—which will result in shorter lead times with future projects,” said Hummel. (It should be noted that Newport’s history of modular construction for shipbuilding goes all the way back to CVN 71—improving incrementally over time with each project.)
As mentioned earlier, the Kennedy project has thus far
involved a 704-metric-ton lift, but as Butler pointed out, this will end up being more of a medium-to-large lift. “We’ll probably end up doing fifteen to twenty lifts on
this project that are over nine hundred metric tons.” Dave Vandergrift, Newport trade director added, “Te crane was a 900-metric-ton crane when it was purchased, and through engineering, they’ve upgraded the capacity of it to a 1,050-metric-ton—which will be able to perform various lifts based on configurations as the build cycle matures— eventually maximizing the capacity of the 1050.”
WIRE ROPE EXCHANGE MARCH–APRIL 2017 29
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