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Anticorrosion Solution for Remote Minehunting System (RMS) Tow Cable


OBJECTIVE: The objective is to develop an anticorrosive coating or other effective anticorrosion solution for the Remote Minehunting System tow cable that achieves requirements of long-term durability and robustness in harsh marine operational conditions. DESCRIPTION: The Remote Minehunting System (RMS), as described in Reference 1, is composed of the semi-autonomous semi-submersible Remote Multi-Mission Vehicle (RMMV) coupled with the towed AN/AQS- 20A mine-hunting sonar system. The RMS is launched and recovered from both variants of the Littoral Combat Ship (LCS) seaframes to perform mine countermeasure (MCM) missions. Stainless steel tow cables, used to tow the AQS- 20A from the RMMV, are experiencing early life corrosion due to excessive salt water deposit buildup that occurs over repeated operations and subsequent system stowage. The tow cable strands are made from Nitronic 50. In operational use, the RMMV streams the AQS- 20A, during which the tow cable experiences significant bending and abrasion as it is unwound from the stowage drum and passes over a traction drive and tow sheave. Upon completion of a minehunting operation, the RMMV retrieves the AQS- 20A by winding the tow cable back through the tow sheave, traction drive, and onto the stowage drum. The RMS is recovered and removed from the seawater. The RMS is then stored, leaving the tow cable to dry on its stowage drum on the RMMV without the salt water or its deposits being cleaned from the cable. Consequently salt deposits build up on the tow cable, producing corrosion and tow cable failure, potentially resulting in AQS 20A damage or loss during a subsequent operation. Freshwater washing of the unwound tow cable is not practical during rewinding or in between operations, due to constraints on space, manpower, and freshwater availability that would be required to unwind and wash the cable. Although this topic focuses on anticorrosion coatings, proposals for other effective solutions that maintain the current cable system and meet the specific goals of the topic will be considered. Current state of the art anti-corrosion coatings are intended to treat solid, flat, and unbendable surfaces, such as ship hulls and bulkheads. Also, current anti-corrosion coatings for cable application are not designed for significant bending, abrasion, and seawater flow operations. The innovation desired is an anti-corrosion solution, like the generalized solutions discussed in References 2 through 4, which is able to withstand the rugged environment of being repeatedly submerged, abraded, bent, wound, unwound, and towed through seawater without degradation. The solution should be long-lasting, durable, and robust. An effective barrier between the deposited salt and the tow cable will lead to increased tow cable life, resulting in cost savings and reduced risk of losing or damaging the towed AQS- 20A during operations. The solution must address the current stainless steel cable; proposals for protecting cable strength members other than Nitronic 50 will be deemed non-responsive. Reference 5 provides additional information important to understanding the problem and to developing potential solutions. PHASE I: The company will develop concepts for the anti-corrosion solution for the RMS tow cable that meet the topic objectives. The company will demonstrate the feasibility of the concepts in meeting the objectives and will establish that the concepts can be feasibly developed into a useful product for the Navy. Feasibility will be established by material testing and simulations of the coated tow cable. Feasibility analysis shall be documented in a final report. The report shall outline the proposed anti-corrosion solution and capabilities, as well as any experimental and modeling results. The small business will provide a Phase II development plan with performance goals and key technical milestones, and that will address technical risk reduction. PHASE II: Based on the results of Phase I and the Phase II development plan, the small business will produce a prototype anti-corrosion solution for evaluation in a laboratory environment. The solution will be evaluated by the company to determine its capability in meeting the performance goals defined in Phase II development plan and Navy requirements. The company will develop a procedure to apply or integrate the coating or other effective solution. The company will demonstrate performance through accelerated testing and simulation of numerous cable deployment cycles in conditions equivalent to those it would experience in actual operation. The company will use the evaluation results to refine the product and application or integration. The company will prepare a Phase III development plan to transition the technology to Navy use. PHASE III: If Phase II is successful, the company will be expected to support the Navy in transitioning the technology for Navy use. The company will develop an integration plan for use in an operationally relevant environment. The company will support the Navy for test and validation to certify and qualify the anti-corrosion solution for Navy use. PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: Corrosion remains a large and costly problem in the military as well as the commercial sector. The petroleum industry, research institutions, and fishing industry all experience costly repairs and equipment downtime due to corrective maintenance caused by corrosion of marine tow cable equipment. Extending the life of their tow cables by using a long-lasting and robust coating or other effective solution that minimizes or eliminates the need to reapply it will significantly reduce costs and minimize risk. In addition, the coating could have broader applications than to just tow cables. REFERENCES: 1."Remote Multi-Mission Vehicle (RMMV) Fact Sheet."Department of the Navy Research, Development, and Acquisition. Program Executive Office, Littoral Combat Ships (PEO LCS), 29 February 2012. 2."Corrosion Protection of Steel."Keys to Metals. 01 March 2012. 3. Wood, Herbert T."A Survey of Publications Dealing with Corrosion in Wire Rope."Defense Technical Information Center. January 1971. The Catholic University of America. 8 May 2012. 4."Wire and Fiber Rope and Rigging, Naval Ships Technical Manual, Chapter 613". Naval Safety Center. Naval Sea Systems Command. 1 July 2008 (Revision 4). 9 May 2012. 5."Additional Guidance for Anticorrosion Solution for Remote Minehunting System (RMS) Tow Cable."
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