John F. Kennedy (CVN 79) is on track to complete erection of the ship’s hull with 452 crane lifts, 44 fewer than Gerald R. Ford (CVN 78) and 142 less than George H.W. Bush (CVN 77), the last Nimitz-class carrier.
Not only are fewer crane lifts assisting with the construction of Ford-class carriers, but what they are lifting are getting larger and much more complete.
“Larger superlifts do three things,” said Kennedy’s construction director. “They allow for increased pre-outfitting; they move steel work from the dry dock to the final assembly platen, which is a less expensive work center, and they have the potential to shorten the erection schedule.”
Aircraft carriers are built using modular construction—a process where units, or small sections of the ship, are welded together to form larger structural units called superlifts. The superlifts are then lifted into the dry dock where the carrier is assembled.
Modular construction is not new to the Ford class of carriers—it was first used on USS Theodore Roosevelt (CVN 71), the fourth of 10 Nimitz-class carriers. What’s new for the Ford class is the size and complexity of the superlifts before they even make it into dry dock.
Case in point: One superlift for Ford, the lead ship of the class, weighed 1,026 metric tons—roughly the weight of six Boeing 747 commercial airplanes. The 128-foot wide, 128-foot long superlift consisted of 14 smaller steel sections, which contained equipment for firefighting, jet fuel systems, catapult systems, jet blast deflectors, and electrical servicing stations.
“One of our key Game-Changers for CVN 79 is focused on moving more outfitting from the dry dock to the Final Assembly Platen,” said the program director for Kennedy. “Building larger superlifts is a critical part of that plan.” The Final Assembly Platen is a large area adjacent to the dry dock where superlifts are built and outfitted.
To support building larger and more complete superlifts, the company is erecting covers on the Final Assembly Platen to help reduce weather impacts. Newport News is also upgrading other tools shipbuilders use to construct Ford-class carriers.
To lift massive superlifts into the dry dock, shipbuilders need a massive crane that can handle the weight.
“Big Blue is our 1,050-ton crane in the North Yard,” said Kennedy‘s construction director. “We can’t build carriers without it.”
The crane was built in 1976 to support up to 900 metric tons, but to hoist Ford-class superlifts, Big Blue’s capacity was reinforced to 1,050 metric tons. The investment has paid off—the heaviest lift performed on Ford weighed 1,026 tons.
The shipyard is also investing an estimated $50 million in welding equipment modernization. Phased to complete in 2019, the investment will bring in modern technologies to improve mechanization, process efficiencies and standardization.
“Welding technology has moved from analog to digital,” explained the lead of Newport News’ welding school. “The shipyard does more automatic welding now, too.” With updated welding equipment, shipbuilders will be more precise with structural welding, pipe welding and more.
And the superlifts are going to get even larger—and fewer—with every ship in the class. One superlift on Kennedy will combine 19 individual sections on Ford, which equates to fewer crane lifts and less manpower.
In addition to increasing in size, shipbuilders are increasing the level of outfitting, or equipment installation, on the larger superlifts prior to placing them on the ship. Using product model data now available to them, shipbuilders can determine when and what equipment installations, electrical work and the like can occur before a superlift makes it into the dry dock.
Something as simple as pre-cutting holes for electrical cables and piping while units are still in the shops translates into huge savings—and fewer backaches—for the ship. When you consider that a Ford-class aircraft carrier is equipped with 13 million feet of cable, 600,000 feet of pipe and 1,800 major pipe assemblies, anything that can be done in advance of ship erect is a good thing.
A shipbuilder, who is a 10-year veteran, serves as an acting general foreman on the final assembly platen and has worked with shipfitter apprentices as a craft instructor. He said that apprentices have always felt overwhelmed by the size of the steel they are working with.
And while one might think bigger means more difficult, larger superlifts are easier on the shipbuilder because more work gets done off the ship.
“We can stage the superlifts much easier on the platen,” said the shipbuilder. “It’s harder to get around, and there are tighter quarters, when you’re on the ship in the dry dock. The more work we can do on the platen, the easier it is on the shipbuilder. If it’s on the platen, we have cranes and forklifts to do the heavy lifting. If you’re on the ship, you are more dependent on your own muscle.”
Moving pre-outfitting off the ship and into the shop goes a long way toward efficiency, said Newport News’ vice president of Kennedy construction. “This allows us to do more work in a more efficient setting, where access to material, the work site and services is better,” he said.
Part of this outfitting is the miles of cable that carry over three times more electrical power than a Nimitz-class carrier. “We got an ‘A’ for thinking our way through the electrical challenges,” said a shipyard official.
Another improvement in the Ford-class shipbuilding process is categorizing the structural units into “families” that are similar enough they can be assembled in a more assembly-line fashion. Of the 1,109 units that comprise the carrier, there are about 140 groups of units that are similar enough to call them “families.”
Newport News is already reaping the benefits of this effort. The first Kennedy “family” of units—17 inner-bottoms—were completed over 300 days faster than on Ford.
These efforts, and tens of thousands of other lessons learned over the years, will assist in getting more of Kennedy built prior to launch. While Ford was the heaviest and most complete carrier at launch, Kennedy is projected to be even heavier before she hits the water for her next phase of construction.
“While carriers are capable and amazing and it’s a carrier Navy, we compete for every dollar we get,” said a shipyard official. “We are trying to make this process the most efficient one that we can.”