It was believed that the USS George H.W. Bush (CVN 77) had successfully completed its sea trails on April 9th, and been accepted by the U.S. Navy. Everyone, including the navy, said so. But it turned out not to be the case, and the navy waited a week to tell the builders that it would not accept the ship until certain discrepancies were fixed.
The problem was that two of the four emergency power generators had some mystery particles in their lubrication oil supply. That explains the delay, as the inspectors take samples of many liquids present on the ship, and have a lab examine them for problems. At the end of the sea trials, all the major items, and all the minor ones that did not require lab tests, were found to be problem free. But the navy had to wait for the lab tests, and the lubricating oil test came back bad. It's not just a matter of replacing the lube oil, but also finding out where the crud came from, and taking care of that. It will take a few weeks to fix that problem, and then the new carrier will be accepted into the navy. The Bush will then spend the rest of the year training, and doing some modifications and fixes on equipment, as a result of the sea trials. The Bush will be ready for its first deployment in about a year.
The Bush is the last of ten Nimitz class carriers. The first one entered service in 1975, and is currently set to serve 49 years before decommissioning. All of the Nimitz class carriers are similar in general shape and displacement. But over four decades, each new member of the class received recently developed equipment. This stuff was installed in older Nimitzs eventually, as they went in for maintenance. The Bush, the last of the Nimitz class, has a lot of new gear that wasn't even thought of when the first Nimitz entered service. The first ship of next class of carriers, the USS Gerald R Ford (CVN 78) will be about the same length and displacement of the Nimitz ships, but will look different. The most noticeable difference will be the island set closer to the stern (rear) of the ship.
The USS Ford, is expected to cost nearly $14 billion. About 40 percent of that is for designing the first ship of the class, so the actual cost of first ship (CVN 78) itself will be some $9 billion. Against this, the navy expects to reduce the carriers lifetime operating expenses by several billion dollars because of greatly reduced crew size. Compared to the current Nimitz class carriers (which cost over $5 billion each to build), the Fords will feel, well, kind of empty. Lots more automation, computer networking and robots. The Bush has a lot of this automation already.
By the time the Ford enters service in 2015, even more of the crew will be replaced by robots than is the case in the Bush. The Ford will have about half as many sailors on board. Carrier based UAVs are also on the way. Work on flight control software for carrier operations is well underway. Combat UAVs (UCAVs) weight about 20 percent less than manned aircraft, and cost 20-30 percent less. They use less fuel as well.
While the navy would prefer to design and build the first generation UCAVs for use on existing carriers, these smaller and cheaper aircraft go together well with smaller and cheaper carriers. This means the Ford class may be the last of the big carriers. That's because UCAVs mean you can get more aircraft on a carrier, and that creates a traffic jam type situation. Moreover, the widespread use of smart bombs means you need fewer bombers over the target. A 50-60,000 ton carrier, with three dozen F-35Bs, UCAVs, UAVs and support aircraft, can be as effective as a Nimitz with 70 F-18s and support aircraft. Thus the Ford class may not completely replace the Nimitz class on a one-for-one basis. The sharply rising cost of building American warships may force the adoption of a smaller, cheaper, carrier class. Much like the Seawolf subs were replaced by the Virginias and the DDG-1000 is being replaced by, well, something smaller and more affordable.