By Geoff Fein
Although the Navy had to install tanks on the aft of Lockheed Martin’s [LMT] first Littoral Combat Ship (LCS) to improve the vessel’s stability, a similar fix won’t likely have to be made on the company’s second LCS, according to the service.
“We have acknowledged that LCS-1, the lead Lockheed Martin ship, came in heavier than expected,” Rear Adm. James Murdoch, program manager LCS, told Defense Daily last week.
He added the Navy knew it would have to make modifications to the USS Freedom (LCS-1) and subsequent Lockheed Martin designs to meet the Navy’s stability requirements.
“We did, in fact, recently [make] modifications to the lead ship, which involved putting tanks on her transom. They are clearly evident,” Murdoch said. “If you look at a picture of the ship today as she [came] out of her most recent availability…if you look at it from a stern aspect, on either side of the steel door we put the steel tanks that project the aft six to eight feet.”
Those tanks help Freedom meet the Navy’s damage stability requirements, he added.
“If she sustained a major hit and sustained some flooding and settled in the water, those tanks would provide the buoyancy to keep her stable and upright and be able to survive that damage,” Murdoch said. “That work is complete on Freedom.”
The Navy knew that as the lead ship was completing construction and the design evolved additional buoyancy was going to be needed in the aft of the ship to meet requirements, Murdoch noted.
“As we went through design and construction on LCS-1, our monitoring of the construction process indicated we were going to need additional buoyancy to meet the Navy’s damage requirements, so we took action to fix that,” he said. “We couldn’t get it into the construction line for LCS-1, that’s why we had to put the tanks on externally.”
When Freedom deploys in the coming months, she will be fitted with those external tanks, Murdoch said.
Lockheed Martin and its partner Marinette Marine recently completed welding of the transom module–the furthest aft module in the ship–on the Fort Worth (LCS-3), he said.
“The ship will have a longer underwater hull body and that will provide quite a bit of additional buoyancy,” Murdoch said. “As we complete construction of LCS-3, we will assess whether we have to put a small set [tanks] above the water line tanks on her as well. Hopefully not, but it’s a possibility it will still be required.”
As for the General Dynamics [GD] ship, the USS Independence (LCS-2), the Navy has been following the same weight monitoring process as on LCS- 1, he added.
“There is some weight growth on LCS-2,” he noted, but not to the same extent as on LCS-1.
Murdoch added that at the present time it doesn’t appear the same corrective action will be required on Independence.
The Navy just completed inclining experiments on Independence. The process takes very precise measurements, looking at what equipment loads are on the ship, what the liquid level is in each of the fuel and water tanks. Then, by placing weights on various places on the ship, technicians can measure very precisely how much the ship angles, Murdoch said.
“That gives you a very precise determination of where is her center of gravity, and that’s the key to understanding the ship’s stability in both what we would call intact and damaged conditions,” he said. “Preliminary reports are that the ship may be somewhat heavier than we expected but will meet requirements and the inclining experiment will confirm that.”
While the Navy has conducted a number of successful combat system tests including structural test firing to verify that the design is correct for the recoil of the ship’s gun, problems did arise with the EADS TRS-3D radar power supply, Murdoch said.
“We had a power card fail in construction and then we had another power card fail. We’ve had the appropriate technical support there and they looked at the radar and the operating procedures for starting it up and shutting it down,” Murdoch said. “With some adjustments to the equipment and procedure, we have been ale to operate the radar very successfully over the last six months. I haven’t had a card failure since last summer. The radar has been operationally reliable, to my knowledge, for maybe six to eight months now.”
On LCS-1, the Navy spent a great deal of time on radar characterization. “We are very interested in what areas are shadowed by the mast or super structure. There isn’t a ship out there where you can put all the radars on top of it,” Murdoch said.
“On any installation we spend a great deal of time, particularly on lead ships, looking at top side design–where are the communications antennas and when are they blocked by other antennas and masts, where are the search radars and what are their blockage zones,” he added.
The Navy has successfully tested the radars and the Identification Friend or Foe.
“As we expected, we encountered blockage areas, mast reflection. In a disciplined manner, we are working through each of those issues to make sure we either correct the problem or the crew knows where their limitations are,” Murdoch said. “I would characterize the testing so far as good. In fact, we have done one live missile engagement against a drone with Freedom. We did achieve a successful intercept and destroyed the target.”
Once Freedom wraps up its early deployment, it will return back to its normal routine, he added.
“We will do this for both ships, an extensive systems series of exercises that will present targets…different types of threats from different angles…it will be extensive testing,” Murdoch said.
On Independence, the Navy worked very hard to make sure for the acceptance trials the combat systems testing was fruitful and provided opportunity to assess the ship’s performance, he said.
“The air search radar performed well, the combat system properly identified the track and handed it over to LCS-2’s missile system, which is called SeaRAM,” Murdoch said.
SeaRAM is made by Raytheon [RTN].
Aside from Aegis destroyers, the Navy does not do live firing exercises, Murdoch said. “We do a non-firing sequence test.”
He added the tests on Independence was “very successful.”
“The detection range was good, the combat system functioned properly, [it] displayed the threat to the operators, the operators engaged it, and we simulated a missile firing very successfully,” Murdoch said. “The INSURV inspectors had very few comments for us on that.”
Murdoch added that those successful tests represented a lot of effort by the Independence team.
“They spent a lot of time last year grooming that system to make sure they understood. In fact, they enlisted the services of local Coast Guard aircraft from the Mobile (Alabama) detachment to fly by the ship as it was at Austal waiting to get underway,” he said. “They did tracking runs with the Coast Guard. It was very successful. We were able to correct a lot of learning issues with [Independence’s] radar systems even before we got underway for trials.”