Tuesday, August 9, 2011

LCSs Sail Through Trials, Tackle Challenges

Launching and recovering small boats. Checking performance in high sea states. Testing firing procedures. Measuring fuel use to find the best speeds to operate the ships. Comparing simulated training with the real thing. Figuring out whether 40 people really can operate a state-of-the-art small combat ship. Fixing what doesn't work.
The U.S. Navy's Littoral Combat Ships, including the Freedom, are being tested as the program is debated in Washington. (U.S. Navy)
That's just the beginning of the list of what the crews of the U.S. Navy's new Littoral Combat Ships (LCS) have been up to over the past year or so. While the program's future continues to be debated in Washington, the Navy and its industrial partners are testing out the first two ships and their complex mission modules. Problems are identified and addressed, and if need be, fixes are made on the in-service ships and design changes drawn up for follow-on ships.
"All designs evolve," said Joe North, the director of Lockheed Martin's LCS program. "Nobody gets everything right the first time around."
In general, however, the Navy seems pleased with its first two LCSs, the Freedom (LCS 1), delivered by a contractor team headed by Lockheed Martin, and the Independence (LCS 2), from a General Dynamics-Austal USA effort.
"It's a good program, in good shape," Adm. Jonathan Greenert, soon to be the new chief of naval operations, said July 28. "Now we need to refine it."
A myriad of items and procedures need to be tested, validated, certified. The ships are filled with new fittings - a situation doubled because there are two unique LCS classes. Each ship introduces a new combat system, has a different propulsion plant, features different mission bay handling systems. New maintenance and support schemes are in place to help the tiny, 40-person core crews keep the ships running.
And tests and trials continue for a variety of vehicles and systems for the mission packages that are the LCS' reason for being.
The development and training efforts are being directed from Naval Sea Systems Command (NAVSEA) in Washington, and the LCS Squadron in San Diego. NAVSEA oversees design and development of the ships, their systems and the mission modules, while the LCSRon is in charge of training and fleet support.
The Freedom, first of the breed, is in a San Diego drydock undergoing a $20 million, four-month overhaul, or "availability." Fixes for several problems are being made on the ship, which will run final contract trials this fall.
A new impressed current cathodic protection (ICCP) system is being fitted to the ship's four water jet tunnels to fix a corrosion problem that caused "minor pitting" in the tunnels, North said. Zinc anodes that were intended to prevent the corrosion problem are being removed, having deteriorated. The same modifications have been made to the Fort Worth (LCS 3) and future ships of the LCS 1 class.
"The ICCP will fix this from ever occurring again," North declared.
Capt. Robert Randall, commodore of the LCSRon in San Diego, said a new coating system will be applied to the water jet intake tunnels.
North noted that the Freedom did not suffer from corrosion on the water jet intakes, a problem that has been widely reported on the Independence, but the original fittings were labor-intensive and expensive. A new design built into the Fort Worth was chosen - a modification, he added, that saved "hundreds of hours" on installation costs.
Another fix will be made to the anchor fitting on the starboard bow. The original design allowed water to come into the anchor compartment when the ship ran at high speeds, causing corrosion. The anchor will be moved to the foredeck, with a new windlass based on the Navy's existing destroyer design.
While in drydock, the ship's hull is being cleaned. The Navy's decision to leave the aluminum superstructure unpainted has not changed, although Lockheed and the Navy are looking at ways to possibly "age" the aluminum.
The metal takes about eight years to fully oxidize, North explained, and will in time change to a dark gray color. No decision has yet been made.
The compressors that provide air to start the ship's gas turbines are being changed. The original compressors had reliability problems, and units similar to those used on the Navy's DDG 51 Arleigh Burke-class destroyers have been installed beginning with LCS 3.
"We expect performance to be a hundred times better than what we saw," North said.
Another change incorporated into LCS 3 will be the addition of 43 metric tons of fuel to expand the ship's range. The Freedom might also get that change in an upcoming yard period.
A new type of water jet will be fitted to the ships beginning with LCS 5, North said, with a more efficient axial flow version of the Ka-Me-Wa water jets.
Changes also will be made on the Freedom to the seals on the aviation hangar's door to eliminate water leaks, and a new mezzanine to store helicopter gear is being built into the forward hangar.
Several changes have been made to the mission bay areas - the heart of the LCS. After the original handling system contractor filed for bankruptcy, a new vendor, Oldenburg, was contracted earlier this year to build the overhead cranes, launching systems, elevators and hatches.
"We overcomplicated" the original system, North admitted. "We probably got a little too complicated in how we thought we needed to do it, with special servo unloaders and stuff like that."
The new system, he said, simplifies the motor designs and controls. The overhead rail system remains, but it is being modified to permit continuous transfer between wet and dry mission bay zones.
The side door that was originally intended to allow the big Remote Minehunting Vehicle (RMV) to be launched and recovered will be smaller starting with LCS 5, North said - a change made because the Navy changed the specifications for the RMV. Since the vehicle now will be moved only through the aft doors, a smaller and lighter side door can be fitted.
One repair that won't be made on LCS 1 will be to the launch ramp in the stern, which was bowed after the big 11-meter rigid hull inflatable boat (RHIB) was stowed on it - contrary, North said, to the manufacturer's specs. Properly operated, the boat should be moved off the ramp for storage.
The ramp is "something we're going to live with" on the Freedom, North said.
But the seal between the ramp and the bottom of the stern doors is being changed. Lockheed and the Navy tried three different seal designs and found them all unsatisfactory.
"We had the whole thing redesigned for Three, and it's a backfit on One," North said.
The Navy is continuing to look for ways to reduce corrosion from the salt environment in the wet mission zone.
"We found that we had equipment mounted in that space that had corrosive material to it. It starts to rust, you've got to worry about it," North explained.
Changes already made or under consideration include moving various items out of the zone, switching to nonrusting composites, and the use of different coatings. The Naval Surface Warfare Center is examining several alternatives.
Permanent repairs to a 6-inch hull crack also will be made to the Freedom while in dry dock.
The Navy and Lockheed said the problem is not with the design, but is a workmanship issue in a particularly difficult area of the hull, in a chine area where different angles come together.
The rest of the chine area on the ship was X-rayed, North said, and no further problems were found.
Lockheed and its Marinette shipyard in Wisconsin have changed the way that area on the ship is built, he said.
"They said it was difficult. Now I know what it is, now we're going to do it different," North added.
The Freedom's aluminum superstructure also suffers from cracks, a condition predicted before the ship was finished in 2008.
At least 14 areas have been found with cracks, North said, and most of those were repaired before the current yard period - "none that we're worried about or are going to limit her in her operation," he said.
Changes have been made in the Fort Worth, North added, that should alleviate the problem.
The ballast tanks added to the Freedom's stern to improve the way the ship sits in the water are built into the hull starting with LCS 3.
"The door arrangement on those has been pushed back," said Capt. Jeff Reidel, NAVSEA's LCS program manager. "It's given some additional room in the bay."
More equipment might be added to the stern area, including a lightweight torpedo decoy system similar to the widely used Nixie system, and a towed variable depth sonar (VDS).
A VDS competition for the anti-submarine warfare module is expected to be take place beginning next year, said Capt. John Ailes, the Mission Module program manager for NAVSEA, with a down-select expected in 2014.
Another change that could be made to the ships is the removal of the fin stabilization system, which could eliminate as much as 28 tons of equipment. Sea tests will determine whether the fins stay or go, North and Reidel said.
Topside, the extra-high frequency satellite antennas originally fitted on LCS 1 have been replaced by super high frequency units, bringing the LCS 1 class into commonality with the LCS 2 design.
One of the more visible changes beginning with LCS 3 is the use of a smaller centerline post in the bridge windows. The wide, triangular metal in the middle of the Freedom's bridge was found to be a distraction. While the post is still necessary for structural reasons, it's been reduced on the Fort Worth and subsequent ships.
After some sea time, a 60-day maintenance period for the Freedom is scheduled to begin Jan. 30 at San Diego, NAVSEA said.
The Fort Worth (LCS 3), launched at Marinette in December, is expected to begin dock trials before the end of August, North said. Builder's sea trials are expected to take place in September on Lake Michigan, with Navy acceptance trials scheduled for November.
Lockheed and Marinette are shooting to deliver the ship in February, North said - six months ahead of the August 2012 contract date. Construction of the Milwaukee (LCS 5) is expected to begin in late summer, he added.
Less information is available on changes made to the Independence. Neither Austal USA, builder of the ship and the prime contractor for the third ship on, nor General Dynamics, which oversaw the first two ships of the LCS 2 class, responded to persistent requests to provide an expert to discuss the ship's current state.
The Navy, in general, also has not matched its public relations efforts on LCS 1 with similar news about the Independence, which has been operating out of the relatively obscure base at Mayport, Fla.
Reidel and Ailes, however, noted the ship has been conducting trials with the RMV and has fully demonstrated its mission bay handling systems, including the twin-boom extensible crane (TBEC) that launches and recovers vehicles out the stern.
"From a mission perspective on LCS 2, the platform has been completed, signed off, sold and operating," Reidel said. "The doors have been tested and operating. All the emergency recovery systems and the reliability fixes have been done and are operating."
The TBEC has been tested at sea, he said. "We were a little bit behind where we wanted to be, but we're in a situation right now where it's full steam ahead. Launch, handling and recovery will no longer hold up our integration testing with the mission packages."
The internal computer networks on both ships are "pretty stable," Reidel said. "The only area [where] we've made changes is some software in the combat systems side. From a network perspective, we've made no changes. Both systems are operating well."
At least for now, one change requested by the crew of the Independence will not be made - the installation of bridge wings to make it easier to navigate the ship in tight spaces.
"It's something we're looking at," Reidel acknowledged. Stealth concerns are not an issue, he explained, since there is no radar cross-section design requirement.
"It's a weight issue," he said, along with concerns about other impacts on the design.
Overall, Reidel said, the LCS effort is in good shape.
"I think that at this point, the program has put itself on pretty stable grounds," he observed.
Later this year, the Independence will shift to Panama City, Fla., to test mine warfare components. Before the end of the year, it is planned to sail through the Panama Canal to transfer to San Diego.
Austal USA is expected to launch the Coronado sometime this year, and began construction of the Jackson in early August.