The Navy modified the Freedom’s RIX air compressors to make them more reliable, and the ship’s compressors are being evaluated for replacement with new Sauer air compressors that were included in redesigns for follow-on LCS-1 class vessels.
Ship sources say compressor reliability remains an issue. Initial LCS requirements called for the ship’s compressors to run 50% of the time, but they are running closer to 90% to compensate for the large-scale leaking of pipes and welds, according to a source intimately familiar with Freedom’s operations. The Navy says the new compressors are similar to the systems employed on LPD-17 ships.
The source says, “Experience operating the Sauer air-cooled compressors indicates they overheat in hot climates — will shut down due to their location in the Freedom-class main machinery space, which is not air-conditioned.” The system, the source notes, has not yet been tested while deployed to warm-weather climates.
In response, the Navy says, “The Sauer system meets all operational and maintenance requirements.”
The Navy also redesigned the reduction gear oil sump covers to stop oil from running down the exterior casing and into the bilge.
“The initial gear design did not have securing mechanisms for the covers to protect the gears from intrusion,” the Navy says. “The original covers were modified to allow them to be locked. This impacted the sealing of the covers. The covers were subsequently redesigned. The redesigned covers are installed on LCS-1, LCS-3 and incorporated into the LCS-5 and follow baseline.”
The Navy has corrected deficient pipe hangars aboard the Freedom and modified LCS-3 drawings and updated that ship’s construction to “include details and guidance for installation on future hulls.”
Program officials have repaired Freedom’s fin stabilizers, which “show poor reliability. This system is currently under evaluation and may not be required to meet performance requirements.”
The Navy now asks dockmasters to move their Yokohama pier fenders for the SSDG engine exhaust “away from exhaust ports, which has mitigated the hazard to wooden piers.”