The Navy currently is conducting a service life extension program (SLEP) to keep 72 LCACs in use until the SSCs can become operational, which is expected to start in 2019. The SLEP will sustain and enhance craft capability, replace obsolete electronics, and repair corrosion damage, according to Naval Sea Systems Command (NAVSEA) officials in the LCAC/SSC program office.
Improvements include boosting engine power from 16,000 horsepower to 19,000 and providing the improved “deep skirt,” which will enhance performance and reliability, NAVSEA officials said.
“Given the age and limitations of the basic LCAC design, SLEP modernization efforts are at the limits of what can be economically achieved for LCAC,” NAVSEA officials said in written responses to questions. “LCACs were designed in the 1970s and built to lift U.S. Marine Corps expeditionary equipment of the 1980s,” they noted.
The deep skirt, which is a requirement for SSC, allows a greater cushion height for the craft, which provides an increase in safety in all sea conditions while allowing operations in a higher sea state and maintaining mission speed and payload, NAVSEA said. It also allows greater obstacle clearance capability, less wear on the skirt and craft equipment, and less maintenance due to reduced seawater spray.
“The result has been a better performing skirt, which requires less maintenance and has a longer service life,” the program office said.
An artist’s rendering of the Ship to Shore Connector proposed by SSC Team Textron (Textron Marine & Land Systems, L-3 Communications, and Alcoa Defense). Image courtesy of SSC Team Textron
As of the end of May, 29 craft had completed SLEP and 10 were undergoing the modifications. The program is expected to be completed by FY 18, at a projected cost of $1.6 billion. The need for a new and improved craft is founded on the fact that the Navy has no other platform to provide the high-speed, heavy-lift, ship-to-shore capability supplied by the LCAC, a Navy spokesman noted. But the LCACs need to be replaced because their basic technology is outdated, they are too expensive to maintain, and they do not meet current lift requirements.
“Given the age and limitations of the basic LCAC design, SLEP modernization efforts are at the limits of what can be economically achieved for LCAC,” NAVSEA officials said in written responses to questions. “LCACs were designed in the 1970s and built to lift U.S. Marine Corps expeditionary equipment of the 1980s,” they noted.
The current Marine equipment is heavier, partly due to the armor added to protect vehicles from the improvised explosive devices that are the primary cause of casualties in Iraq and Afghanistan.
“The increasing weight of expeditionary equipment and subsequent craft performance requirements exceeds LCAC SLEP capabilities and precludes the continuation of the aging LCAC,” NAVSEA said. And “technology has evolved to enable greater availability, performance and reliability for the SSC.”
The NAVSEA officials said release of the RFP was delayed “to allow for finalizing of the program acquisition approach by Navy and OSD leadership.”
Part of the delay may have resulted from the decision by Ashton Carter, the Pentagon’s top acquisition official, to make the SSC program an acquisition category 1 (ACAT 1) priority, which indicates how important it is considered. An ACAT 1 designation meant that the Secretary of Defense’s office was involved, not just the Navy.
An indirect benefit of the delay was refinement of various elements within the RFP’s Technical Data Package in response to questions about the draft RFP submitted by the prospective bidders, NAVSEA said.
NAVSEA said the SSC will provide many improvements over the LCAC, including command, control, communications, computers, and navigation systems that reflect the advances in technology since the LCACs were produced. The SSC also will incorporate material and systems improvements to address the LCAC’s top 25 high-maintenance drivers, including the use of more corrosion-resistant aluminum in the hull and carbon fiber composites in the propeller, the shroud assembly, and propeller shafts. Those material fixes will increase craft availability and lower life-cycle maintenance costs, the program office said.
With a load capacity of at least 74 tons, the SSC will carry heavier equipment, must be capable of speeds greater than 35 knots, and will have four more powerful and more fuel efficient jet engines. The SSC will have a simpler and more efficient power train design, with a reduction in gearboxes from the eight in LCAC to two, greatly reducing complexity and maintenance requirements. It also will use composites in the lift fans and bow thrusters, in place of the aluminum used on LCAC, which should increase service life and lower upkeep cost.