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Technology Development of Fiber Optic Moorings for Surface Communication Buoys


TECHNOLOGY AREA(S): Info Systems, Ground Sea, Electronics 

OBJECTIVE: Design and test compliant mooring connection cables. The cables would be used to moor buoys in ocean waves and ocean currents such that the moorings will include optical fibers. The cable must be able to withstand motions of buoy tugging on the cable in ocean waves, ocean currents and wind loading. 

DESCRIPTION: This SBIR topic seeks to support the transmission of Navy sensor data to and from subsea nodes to airplanes, Navy ships, and satellites. The status quo is to use a geometric compliant mooring cable with clamp-on floats, which is not suitable for specific Navy programs that require unique deployment and winching operations. An example would be an underwater winch that pays out cable to a buoy and then winds the cable back into a garage. The target cable to be designed and tested under this SBIR topic will be for small-size buoys with displacement ranges of 100-500 pounds. The focus will be axial stiffness and fatigue life of the compliant cable. For proposal purposes, assume the compliant cable section will need to have a low stiffness (axial) to stretch in the range of 10 feet in the range of 50-100 pounds, and operate reliably for a duration of 60 days at sea in Sea State 3-4 conditions. The compliant stretchable cable section will need to be (a) light weight in seawater (for instance, it is desired to be neutral buoyant to not have a large dead weight pulling down on the buoy reserve buoyancy) and (b) as small diameter is feasible to reduce fluid drag loading which would adversely impact the surface buoy performance and (c) have a diameter of 3 inches or less if feasible (the diameter is the structural member, the flexible member, the fiber optic cable included). In addition, if this compliant cable is to be flange connected to interface to the surface buoy and interface to the remaining fiber optic mooring cable, it is desired to have the flanges as compact as possible to reduce handling and dead weight and for fluid drag loading on the buoy mooring as a whole. Work produced in Phase II may become classified. Note: The prospective contractor(s) must be U.S. owned and operated with no foreign influence as defined by DoD 5220.22-M, National Industrial Security Program Operating Manual, unless acceptable mitigating procedures can and have been implemented and approved by the Defense Security Service (DSS). The selected contractor and/or subcontractor must be able to acquire and maintain a secret level facility and Personnel Security Clearances, in order to perform on advanced phases of this project as set forth by DSS and NAVFAC in order to gain access to classified information pertaining to the national defense of the United States and its allies; this will be an inherent requirement. The selected company will be required to safeguard classified material IAW DoD 5220.22-M during the advanced phases of this contract. 

PHASE I: Design and conduct proof-of-concept studies for a compliant mooring connection cable that includes optical fibers. Develop a Phase II work plan. 

PHASE II: Design, manufacture, and test prototypes using a dry laboratory with a cyclic testing machine, in consultation with NAVFAC mooring and buoy experts. Perform cycle load studies of the cable to simulate ocean waves and then test the fatigue and optical light wave signals strength with time. It is probable that the work under this effort will be classified under Phase II (see Description section for details). 

PHASE III: Produce compliant fiber optic cables per specifications required by each Navy project that needs these moored transceiver buoys. Assist the Navy in transitioning the technology to the fleet. Other dual use applications are the technology can be spun off to the ocean science measurement community at large that needs high bandwidth data from small buoys. While the technology is targeted for small buoys, in theory, it may be scalable for larger, longer-duration buoys typically used in the science community (e.g., Scripps Institute of Oceanography, Woods Hole Oceanographic Institution, Monterey Bay Aquarium Research Institute). 


1: Paul, Walter. "The Use of Snubbers as Strain Limiters in Ocean Moorings", Dept. of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, MA.

2:  Farr, N., Frye, D., Grosenbaugh, M., Paul, W., Peters, D., and Chaffey, M. "Development of a Nylon EOM Mooring Cable for Moored Ocean Observatories", ONR/MTS Buoy Workshop, 2006.

KEYWORDS: Buoy; Mooring; High Bandwidth; Subsea Nodes; Fiber Optic Cable; Data Transfer; Snubber Hose; Compliant Mooring Cable 


Warren Bartel 

(805) 982-1215 

Bradley Hunter 

(805) 982-5319 

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