The U.S. Navy has already altered its Freedom Class Littoral Combat Ship, , to address problems uncovered in testing, but the ship still needs to be fundamentally redesigned, say leading defense analysts.
They base their conclusions on briefings from the Aviation Week Intelligence Network (AWIN) revealing findings of Navy and industry reports detailing the vessel’s hull and deckhouse cracking and engine problems. AWIN was given exclusive access to the documents.
The analysts also call for an investigation into how the ship was accepted in such — in their view — questionable shape.
“What the documents show is grounds for questioning this LCS variant’s viability,” says Ben Freeman, national security investigator for the Project On Government Oversight, who also was briefed on the reports.
“If the reports outlined are as serious as indicated, then there may be some significant redesign work required — even beyond the modifications to LCS-1 that have been made based on initial lessons learned with the first hull,” says Bob Nugent, vice president of advisory services for consultancy AMI International’s Washington operations.
“This would impact the Freedom LCS design joining the fleet in the numbers and on the schedule currently programmed,” Nugent says. “Since LCS is so central to future surface force numbers, this would translate into shortfalls in providing surface ship forces required by the combatant commanders.”
There are two very different LCS designs: LCS-1, developed and produced by an industry team led by, and , developed and produced by a team led by . Service plans have included an LCS fleet of about 55 ships costing more than $30 billion to buy. Citing budget requests, the Congressional Research Service lists the estimated “end cost” of LCS-1 at $537 million.
The reports accessed by AWIN dealt only with LCS-1. They were generated during the first half of last year, following the ship’s initial operations, and detail the cracking and engine problems on the ship. The reports include pictures of 17 cracks as well as a chart listing their location, length and other attributes.
The cracking was so pronounced even before the second set of rough-water trials were set to begin last year, the reports show, that the Navy sent engineers to the ship to monitor the cracks.
As a result of the cracking issues, the ship designed to be the Navy’s cheetah of the seas and envisioned as comprising about half of the service’s future surface combatant fleet was limited to a “safe operating envelope” in which it could travel no faster than a laden cargo freighter in sea-state 5 conditions, the reports show.
Sea-state 5 is in the middle of the scale of ocean conditions, with waves of 8.2 to 13.1 ft. — considered to be “rough” water, one level higher than “moderate.”
Navy LCS officials issued the near-term guidance with the new operational limits, depending on sea conditions and time away from port, about three months after the service acknowledged finding a single crack aboard the ship, the reports show.
That guidance was to be re-evaluated after the ship’s post-shakedown availability (PSA). LCS-1 started its PSA in June, the Pentagon notes, and remained in the shipyard through the end of the year.
The reports indicate that mission planners were told LCS-1 would sometimes need to alter or ditch planned missions if it encountered sea conditions outside of its safe operating envelop. In rougher seas sailors have been told to avoid roll angles greater than 45 deg.
Norman Polmar, a defense analyst and author of books on Navy-related issues, says, “They’ve cut back considerably on how fast and how far they can go.”
Says John Gresham, another defense analyst and author, “This is extremely bad and potentially dangerous.”
He adds, “The cracks in the hull of the Freedom are particularly troubling, because it is composed of conventional steel construction. The development of hull cracks on the Freedom so early in its service life indicates that the water-planing hull design is generating stresses that were not anticipated when it was designed. There clearly is a need to take one of the follow-on units of the class and install a full instrumentation harness to fully understand the stresses on the hull and deckhouse to establish safe operating parameters, along with long-term fixes for the entire class.”
While operating under the limiting guidance, the ship’s crew has had to perform extra inspections — weekly or daily — to find cracks and “limit” their size, and to inspect the ship after the hull has been slammed by waves or rougher seas.
“This is unbelievable the amount of inspection,” Polmar says. “How do you limit the maximum size of a crack? They’ve already found an 18-inch crack in a ship. If they’re in the middle of the ocean and they find a crack three inches long, do they have to stop the ship? It’s ridiculous they have to look for that.”
One crack identified in the report could only be viewed by using a mirror while hanging over the side of the vessel. “That means ship crew operating at sea for three months have got cracks they couldn’t find,” Polmar says. “This is the most damning thing I’ve heard in years.”
At least one re-cracking was found, and in at least one other case it was too difficult to determine whether there was further cracking because the area was too hard to see.
The analysts were equally dismayed about the reports’ findings on the engine failure reported earlier with the ship. The reports show theTrent MT30001 gas turbine engine shut down when components failed because of corrosion and oxidation following a number of significant and unexpected ingestions of seawater over an 18-month period.
“That is ludicrous,” Polmar says. “Once again, it’s a faulty design. Gas turbine engines have been around since 1943. We’ve been building gas turbines ships in our Navy since the 1960s.”
Part of the problem, Gresham notes, is the ship’s need to vent water from the pump-jets into the ocean. “The business ends of them are going to have inlets, and they’re going to have to be in the water. They are going to spend months and years at a time immersed in saltwater.”
One day, the engine ingested about 475 gal. of seawater. At least 1,000 gal. of water, combined, were consumed by the engine during seven subsequent occasions, the reports say.
Significant quantities of salt were discovered through the starboard engine and intake system, according to the reports. Internal components also showed signs of corrosion — apparently due to unanticipated and prolonged exposure to moisture and salt.
All the engine hardware deterioration was due to seawater contamination, the reports say.
“There needs to be an end-to-end engineering design review of the propulsion/power systems,” Gresham says.
“If it were my boat, I would tie the ship up and have a commercial tug take it back to the builder and demand he fix her,” Polmar says. “I’d stop production until that first ship is fixed and guarantee that similar problems don’t occur on the follow-ons.”