December 26, 2012
Credit: Credit: US Navy
As the Littoral Combat Ship (LCS-1) USS Freedom got under way in late November for ship-and-crew-deployment certification trials, it was clear that the LCS program team had made a priority of fixing some major ship issues noted earlier in the year by Aviation Week during an unsanctioned guided tour of the ship while it was in a U.S. Navy dry dock in San Diego.
After first denying the veracity of many of Aviation Week’s observations, Navy officials said they would make repairs for most of the problems a priority. Most of the major issues have been fixed or are scheduled to be addressed.
For example, Aviation Week had noted extensive corrosion throughout many parts of the ship. “LCS-1 was designed and built with an active anti-corrosion system, which was further extended during post-delivery to address additional areas of concern,” the Navy says. “This system is in the baseline for LCS-3 and follow hulls. Minor corrosion was also experienced in limited areas of the ship, which have been addressed through modifications to the paint schedule and material … [which also] are in the baseline for LCS-3 and follow hulls.”
Also, during Post Shakedown Availability 2 (PSA-2), the main machinery room was completely repainted and additional preservation measures were implemented, including painting the piping that had not been previously painted, the Navy says.
Aviation Week also had noted pinprick holes and leak damage in critical piping systems. “The shipbuilder performed non-destructive testing (NDT) as required and utilized acceptance criteria that conformed to Naval Vessel Rules,” the Navy says.
Marinette Marine, LCS-1 prime contractor Lockheed Martin’s shipyard partner, relies upon a vendor to conduct radiographic testing (RT), the Navy says, adding that the vendor’s procedure for RT on LCS-1 was reviewed and approved by the American Bureau of Shipping. The vendor performed RT of all of the water mist weld joints in January 2007, with the results and films reviewed by ABS.
The Navy says it has “since found that the manner in which the [RT] was accomplished during construction did not highlight the defects.” As a result, the Navy says, “weld procedures and NDT procedures have been changed on LCS-3 and follow [ships], including increased Navy quality assurance.”
The gas-turbine engine intakes were redesigned and “improved mating seals” were installed on the ship, as well as later Freedom-class models, to prevent the cascade of issues that caused the starboard engine to fail through corrosion-induced metal fatigue.
Freedom program officials also redesigned the Isotta Fraschini ship’s service diesel engines (SSDGs) to address “performance issues” documented during Freedom’s early deployment. An Aviation Week review of casualty reports and engineering logs reveal reliability and related issues with those engines through the beginning of this decade.