WASHINGTON – The new littoral combat ship (LCS) Jackson was showered by spray and shaken by a large explosion June 10 as she endured the first of a series of controlled tests intended to prove the design's ability to withstand and survive combat and damage.

A 10,000-pound explosive charge was set off about a hundred yards from the Jackson – the Navy wouldn't say exactly how close, saying the actual distance is classified – in waters off Florida's Atlantic coast.

So was there any damage?

"Nothing unexpected," said Capt. Thurraya Kent, a spokesperson for the Navy's acquisition directorate. She acknowledged that minor damage was expected, such as items falling to the deck or glass cracking, and some components could be stressed.

Other sources indicated that initial results show the ship withstood the explosion better than expected, although evaluations continue.

About 260 instruments are placed throughout the ship to measure various aspects of the blast, which strikes above and below the water. After the test, the Jackson returned to the Mayport Naval Station where engineers downloaded instrument data, examined the ship and made necessary repairs, Kent said.

Another test is scheduled to take place around June 22, she said. A third and final shot planned for July 8. Each test will use the same 10,000-pound explosives charge, but the ship will be moved progressively closer to the explosion.

The test schedule, Kent noted, is volatile, subject to weather conditions, traffic in the vicinity of the blast and marine fish and mammal activity. The first test, she noted, was delayed several days by weather.

The ship's crew of about 50 and a number of engineers and observers – many from the Pentagon's Office of Test and Evaluation (OT&E) -- were on board during the test. Kent added that a veterinarian was included "to assess sea mammal's safety and security."

"We take the safety and security of marine mammals seriously," Kent added. "We have to keep in mind migration patterns in addition to the other variable of sea state and weather. We also have additional lookout, more than you would normally have when you're out to sea. We do not conduct test shots if a marine mammal is in the proximity."

Full Scale Shock Trials (FSST) are performed on most new US Navy ship designs, although Congress – at the urging of Pentagon OT&E director Michael Gilmore – actually wrote into law a requirement for the LCS tests. Thus, the tests are coming earlier in the LCS production line than originally planned.

Gilmore himself is expected to be aboard for the third test shot on Jacksonville.

The last time the Navy conducted FSSTs was in 2008 with Mesa Verde, the third ship of the San Antonio-class of amphibious transport docks.

Kent noted that a great deal of testing already has been accomplished on individual components built into the ships.

"Individual equipment shock trials, modelling and testing and other surrogate testing already have been done. They give you an idea of what to expect," she said.

"Shock trials become the validation of those tests and demonstrate the ship's ability to withstand an explosion. Shock trials are actually the culmination of all the trials that have been done to date."

With two different LCS designs in production, there will be two series of shock trials. Jacksonville represents the Independence LCS 2 class, while the Milwaukee will test the Freedom LCS 1 design.

The Milwaukee recently completed a maintenance period and is also operating from Mayport. Her first test shot is scheduled for Aug. 9 and the last on Sept. 13. The ship recently completed a firing exercise using her 57mm gun.

160608-N-UK306-001 JACKSONVILLE, Fla. (June 8, 2016) Freedom-variant littoral combat ship USS Milwaukee (LCS 5) transits out Naval Station Mayport after a maintenance period. (U.S. Navy photo by Mass Communication Specialist 2nd Class Timothy Schumaker/Released)
160608-N-UK306-001 JACKSONVILLE, Fla. (June 8, 2016) Freedom-variant littoral combat ship USS Milwaukee (LCS 5) transits out Naval Station Mayport after a maintenance period. (U.S. Navy photo by Mass Communication Specialist 2nd Class Timothy Schumaker/Released)

The Freedom-class LCS Milwaukee getting underway from the Mayport, Fla., naval base on June 8 for exercises.

Photo Credit: MC2 Timothy Schumaker, US Navy

The full series of LCS shock trials will cost about $65 million, Kent said, using research, development, testing and evaluation funding.

In the Pacific, meanwhile, the Freedom and another Independence-class ship, the Coronado, are preparing to take part in Rim of the Pacific (RIMPAC) exercises that begin in late June.

The Coronado completed the initial operational testing and evaluation of the SeaRAM Rolling Airframe Missile weapon system for its class on June 2, and is expected to leave San Diego for Hawaii June 22, fitted with launch canisters for the Harpoon missile, the first installation of a new over-the-horizon (OTH) capability developed by the Navy.

After taking part in RIMPAC, the Coronado will continue to Singapore to begin the first deployment of an LCS 2-class ship. She's expected to operate in the region up to 18 months or more.

The Freedom will not travel to Pearl Harbor, but rather will take part in a Southern California series of RIMPAC exercises with five other ships. This fall, she will be fitted with launchers for the Raytheon/Kongsberg Naval Strike Missile, a Norwegian weapon that is being considered, along with Harpoon, as the OTH weapon for LCSs and the follow-on LCS frigate.

And in Singapore, engineers are working to restore as much of the Fort Worth's engineering capability as possible before the ship leaves for San Diego.

The Fort Worth's power plant was severely damaged Jan. 12 in a pier side accident at Singapore's Changi naval base, in which the ship's engines were mistakenly engaged and the combining gear, a complex piece of equipment that allows the ship's two gas turbines and two main propulsion diesel engines to be cross-connected to propulsion shafts, was wrecked.

In a combined diesel and gas turbine plant, ships routinely travel on economical diesel engines, bringing on the less-efficient gas turbines for high speeds. Travelling long distances on gas turbines alone is inefficient, potentially damaging to the plant, and requires frequent refueling. Nevertheless, the Navy decided in April the ship would return to San Diego for full repairs, even if she could only use her turbines. At that time, it was hoped the Fort Worth could leave Singapore as early as June.

But, according to several sources, engineers now believe they're able to get at least one of the diesels on line for the passage, using a combination of software reconfiguration and partial mechanical repairs. Some are reportedly hopeful both diesels can be used.

A test configuration already has been successfully evaluated aboard the Fort Worth's sister ship Freedom.

Reconfiguring the engineering plant, however, will add to the time needed to prepare the Fort Worth for the long trans-Pacific voyage. Combined with the need to provide an escorting oiler – many of which will be engaged in RIMPAC – it's now likely the Fort Worth won't leave Singapore at least until sometime in August. That raises the possibility that the Coronado could arrive at Changi before Fort Worth leaves.

Sidelined by an accident that caused severe damage to its propulsion plant, the Fort Worth sits pierside at Singapore's Changi Naval Base in February.

Photo Credit: Christopher P. Cavas / staff