The U.S. Navy postponed the future USS Minneapolis-St. Paul’s (LCS-21) commissioning due to a defect in the primary propulsion system.
“A recent Freedom-class design defect associated with bearings in the combining gear’s high-speed clutch has industry and the Navy team pursuing a design fix for ships under construction as well as several of the ships that entered the Fleet,” said Alan Baribeau, Naval Sea Systems Command, Office of Corporate Communication.
There is no timeline for deciding what the repairs will be, how long they will take, or what the cost would be were provided.
Recently, defects in the propulsion systems (particularly reduction gear) of LCSs started to occur in the media. Over the last year, the U.S. Navy has linked propulsion failures in USS Detroit (LCS-7) and USS Little Rock (LCS-9) to a latent engineering defect in the bearings system. The bearing system associates Rolls Royce MT30 gas turbines and Colt-Pielstick diesel engines, which power the main drive shaft to achieve the ship’s 40-knot top speed.
LCSs are ships with the highest speed in their tonnage. The factor of reaching this speed is the propulsion system and reduction gear. Though LCSs have an incredible pace, successive failures at their propulsion systems started to disrupt the tasks. Lockheed Martin is trying to develop solutions, but the solutions require a lengthy repair time as the ships need to be docked and hull cut.
After the reduction gear defect occurred in USS Detroit (LCS-7) in October 2020, The U.S. Navy ordered the ships to be used below a certain speed to cause the vessel to undergo unplanned repair as a temporary solution.
Moreover, the U.S. Navy had requested extensive inspection at the propulsion systems of the new LCSs at the harbor and sea trials and postpone the commissioning if necessary. USS Minneapolis-St. Paul (LCS-21) is the first ship whose commissioning was delayed after this decision.
USS Minneapolis-Saint Paul (LCS-21) is a Freedom-class littoral combat ship of the United States Navy. She is the second ship in naval service named after Minnesota’s Twin Cities. On 29 December 2010, Marinette Marine was awarded the contract to build the ship in Marinette, Wisconsin. She was launched in June 2019 at the Fincantieri Marinette Marine Shipyard in Marinette, Wisconsin.