The RICOH Challenger for U.S. Navy Aircraft Carriers: Refueling a nuclear-powered aircraft carrier is among the most complex industrial tasks. It involves lengthy, highly specialized procedures to ensure the carrier can surge several decades into the future.
The Refueling and Complex Overhaul (RCOH) process for carriers occurs as a “mid-life” service extension and massive upgrade. It involves opening a huge hole in the ship to enable access to the reactor and other critical ship systems.
The process is highly involved, as the reactor must first be brought into a low-power state before being fully shut down and left to cool off for several days until procedures can begin.
The process, many times, can take years.
Dismantling the Aircraft Carrier Reactor
Once cooled, the top of the reactor must be cracked open by removing bolts and lifted off with a large crane.
Once the top of the reactor is off, new fuel assemblies are added in place of old ones in large increments. Several hundred rods can be removed at once, but all of the nuclear reactor’s rods must be replaced to refuel the boat fully.
This entire process takes a bit of time, as it must be done carefully and precisely. Following this process, the large top of the reactor can be bolted back on after all the water is pumped out.
Massive Modernization
The RCOH process, however, involves much more than refueling the reactor, as many other systems on a carrier can only be upgraded while the reactor is offline. When the reactor is taken apart, a massive amount of additional work occurs, given that new access areas are opened up and available for maintenance crews to reach.
This procedure relates to the most significant unrecognized reality of an RCOH: the modernization elements. With access to the ship’s critical systems enabled by the refueling process, engineers can upgrade the ship’s electronics, command and control systems, digital sensors, radar, and computing.
An RCOH offers an opportunity for a massive modernization overhaul of the carrier’s weapons systems, fire control apparatus, and overall wiring. Much of the hardware likely needs to be replaced due to wear and tear through service, yet many opportunities exist to upgrade much of the software woven through the ship’s computer systems.
Alongside the modernization, RCOH opens up vast, typically empty caverns in the body of the ship where key equipment such as generators, pipelines, water supplies, and other ship necessities are housed and shepherded through or utilized as needed.
Extensive piping runs throughout the body of a aircraft carrier to carry water and cooling materials while also ensuring onboard generators sustain the power supply throughout the ship.
All of this takes time. Once upgraded, much of the ship needs to be reassembled, and parts of the hull and internal steel casings need to be cleaned off and reinforced in some cases. The process can be lengthy and cumbersome, and while it is expected to finish in roughly four years, many RCOH efforts can take up to six years.
Aircraft Carrier Fleet Size
The complexity and duration of the RCOH dry dock period is a primary reason why the US Navy maintains at least 11 aircraft carriers.
At any one time, typically four aircraft carriers are at sea patrolling or on key deterrence or global stability missions, three or four more are docked and standing by in case of an emergency or fast-erupting conflict, and three carriers can be dry docked for repairs, refurbishment or RCOH.
This essential breakdown enables the US Navy to consistently have seven or eight ready carriers in position to support operations worldwide, ensuring massive power projection potential for the US Navy.
There are many theaters of operation, and the regular availability of deployable aircraft carriers is highly relevant in light of the Pacific, as the vast region can accommodate as many as three Carrier Strike Groups at once.
One aircraft carrier is permanently based in Yokosuka, Japan, and five more are spread across the Western coastline of the United States, including San Diego and Bremerton, Washington.
About the Author: Kris Osborn
Kris Osborn is Military Technology Editor of 1945 and the President of Warrior Maven – Center for Military Modernization. Osborn previously served at the Pentagon as a highly qualified expert in the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Masters Degree in Comparative Literature from Columbia University.

Bildge water
April 18, 2025 at 8:21 am
They make the ship out of Chinese parts and Chinese parts have hidden back doors that turn on and off your equipment. Like a remote control drone. Old ship’s are more reliable than new ship’s just don’t load them to capacity or else you’ll be on the bottom of the ocean with a full load of ammo.
Lhasa
April 19, 2025 at 1:21 pm
Only the USS Washington took 6 years due to delays from Covid. RCOH normally takes 3-4 years depending on what needs to be done.