Under the direction of Naval Surface Warfare Center (NSWC) Carderock Division engineers, the live-fire program for the Navy’s ship-to-shore connector (SSC) recently completed three system level tests using a retired landing craft, air cushion (LCAC) as a surrogate for the SSC to assess vehicle vulnerabilities.
The fabrication of the first two SSCs (LCAC 100 and LCAC 101) are well underway. Delivery to the Navy of the LCAC 100 is expected in 2017. At this time, the post delivery test & trials (PDT&T) phase will begin. The Live Fire Program, which is led by NSWC Carderock Division will continue during this phase. Live-fire tests during PDT&E will include a sea state survivability test, susceptibility testing, and controlled damage tests where the crew’s response to virtual or real damage is assessed.
The SSC program, managed by the Program Executive Office Ships, Amphibious Warfare (PMS 377), will build 72 production craft that will serve as the evolutionary replacement for the existing fleet of LCAC vehicles.
“As required of all manned weapon systems, which includes naval ships and craft, the SSC must undergo realistic survivability testing, prior to its full-rate production, to determine the vulnerability of the craft and its crew to threats likely to be encountered in combat,” said Gerald Lawler, NSWC Carderock Division senior vulnerability analyst for combatants. “When a weapon system is considered to be unreasonably expensive to destructively test, such as naval vessels, the live-fire legislation allows for the testing of surrogates in place of the actual system.”
Given that the SSC is being designed to replace the LCAC and is similar in its overall dimensions, skirt system, and propulsion machinery to the LCAC, the overall damage to the LCAC for the threats tested would be expected to be similar to the damage inflicted upon an actual SSC.
In July 2012, the Navy announced the retirement of several LCACs in the FY14 to FY15 timeframe, said Lawler.
“The potential availability of these craft provided the program sponsor [PMS 377] the opportunity to perform a full-up system-level test on an operational SSC surrogate as part of its overall live-fire testing program.”
Discussions with Assault Craft Unit Four (ACU 4) began in March 2013 as to the potential craft candidates and the transit of the craft, approximately 165 miles, to a test range at Aberdeen Proving Ground (APG) in Aberdeen, Maryland.
In June 2014, LCAC 20 was selected by ACU 4 as the test craft.
On April 27, 2015 the LCAC 20 and its escort craft, LCAC 37, arrived at the UNDEX Test Facility off of the Bush River at APG.
During the two-year timeframe prior to the arrival of the LCAC at APG, Lawler and Ben Ridenour, NSWC Carderock Division Vulnerability Assessment branch engineer, developed the test plan, that when implemented, would have to answer SSC critical live fire issues to satisfy the live-fire office within the Operational Test and Evaluation Directorate at the Pentagon, while safely conducting a test involving live ordnance and an unmanned operational LCAC.
“Bringing LCAC expertise from NSWC Panama City Division, active Navy ACU 4 support, and weapons effect testing expertise from the Army’s Aberdeen Test Center together with NSWC Carderock Division's Vulnerability Assessment Branch expertise in live-fire program management and test development was the key factor in achieving these goals,” Lawler said.
“Aside from obtaining a fully mission-capable craft from the Navy for destructive testing, one of the greatest challenges of this test was that the craft had to be operational, on cushion, and under control without an on board crew due to the presence of live ordnance,” Lawler said. “To achieve this condition, a wireless, remote control system was developed by NSWC Panama City Division."
This system enabled the start of the craft’s main engines and the inflation of the craft’s skirt while the craft was unmanned but tethered in the test pond.
Three tests were conducted using actual threat weapons against the operational craft:
Live-Fire Test 1:
The first test, conducted June 16, took place in the littoral warfare environment (LWE) test pond at APG. This test examined the vulnerability of the craft and crew to an underwater threat. The crew was represented with fully outfitted anthropometric test devices (ATD). ATDs are essentially crash dummies that are capable of measuring the forces and accelerations the crew would be subjected to from the weapon effects. Crew injuries were calculated using data from the ATDs.
Live-Fire Tests 2-3:
Shots two and three were conducted July 1 and 28, 2015 respectively on land at the LWE and examined craft and crew vulnerability to an indirect fire threat and a land mine. Crew casualty assessments for each shot were determined by the Army Research Lab (ARL) using the data collected from the tests and crew casualty assessments tools developed by ARL.
NSWC Carderock Division assessed the weapon effects damage to the craft and the degradation of the craft’s systems from successive threat impacts.
“Despite the enormity of the task of conducting several live-fire tests against an operational naval vessel, all tests were successfully conducted and fully achieved their live-fire test objectives,” Lawler said. “This achievement was due in no small part to the cooperation, expertise, and professionalism of all the participating agencies under the direction of NSWC Carderock, and the confidence of PMS 377 in having the NSWC Carderock Division Vulnerability Assessment branch manage and implement the SSC live-fire program.”
NSWC Carderock Division leads the Navy in hull, mechanical and electrical engineering expertise and delivers technical solutions in order to build and sustain a dominant, ready and affordable fleet. Headquartered in West Bethesda, Maryland, approximately 3,600 scientists, engineers, technicians and support personnel are located across the U.S.