The U.S. Navy’s newest aircraft carrier suffered a propulsion issue in January 2018 that forced it to return to port early from sea trials. The USS Gerald R. Ford experienced an issue with the main thrust bearing that was the result of a manufacturing defect. Both the U.S. Navy and shipbuilder Huntington Ingalls Industries are looking into the problem.
The USS Ford was on a shakedown cruise designed to detect issues in the brand-new ship. According to a Navy memo , while the ship was underway the crew and engineers observed a temperature of "92 degrees Fahrenheit above the bearing temperature setpoint."
The main thrust bearings on ships are designed to take thrust generated by the propellers and move the ship in the opposite direction of the thrust. A carrier such as the USS Ford, which has four propellers, in turn has four main thrust bearings. As one might expect with a 90,000 ton, nuclear-powered vessel, this is a juncture of machinery that must safely transfer enormous levels of energy, and heat buildup was detected before something dangerous could happen.
According to the memo, “after securing the equipment to prevent damage, the ship safely returned to port." Another problem involving main thrust bearings took place in April 2017.
Huntington Ingalls declined to state which contractor was at fault for the defective parts, but Bloomberg noted that General Electric was responsible for the Ford’s propulsion system. Bloomberg also noted that an inspection of the parts involved in the January 2018 incident revealed improperly machined gears at GE’s facility in Lynn, Massachusetts as the “root cause."
A spokesperson for GE said that the company no longer produces gears for the USS Ford, which begs the question of when the problem could be fixed. The parts are reportedly "out of spec," and would either need to be repaired and brought back into spec or replaced with properly machined parts.
The USS Ford is the most expensive warship in history, costing $12.6 billion in construction and another $4.7 billion in research and development. The Ford was built with a number of new technologies onboard, including an electromagnetic aircraft launch system, advanced aircraft landing system, and new radar.
All new ships undergo problems, and Ford’s shakedown period is doing exactly what it is supposed to. A first in class ship using new technology, Ford has had more than its share of issues. According to a spokesman for Navy Sea Systems Command, the organization overseeing the shakedown cruise, the problems will be fixed during the “post-shakedown availability” phase, during which improvements are made while the ship is in drydock.