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Surface Ship Fat Line Towed Array Cut-Resistant Vibration Isolation Module (VIM) Hose


TECHNOLOGY AREA(S): Sensors, Electronics, Battlespace 

OBJECTIVE: Develop a cut-resistant hose for surface ship fat line vibration isolation module (VIM) that retains existing VIM hose properties. 

DESCRIPTION: A surface ship towed array VIM hose that is resistant to cuts, abrasions, perforation, and other mechanical damage is needed by the Navy. The surface ship fat line VIM is a fluid filled hose that reduces the low frequency vibrations experienced by towed array sensors by attenuating the vibration through the VIM and especially through the hose wall. However, the soft hose material used in current VIM hoses is susceptible to cuts from floating materials such as fishing lines. A cut-resistant towed array VIM hose would increase the availability of existing surface ship towed arrays and reduce lifecycle costs. Reducing or eliminating this failure mode would improve surface ship towed array availability by as much as 25%, with a corresponding reduction to lifecycle costs (repair, sparing, time off station). Current commercial hose solutions, such as hydraulic, pneumatic, and fire, do not meet the needed performance to alleviate this costly failure problem because the materials and constructions developed for those hose types do not address the damping (attenuation) and other environmental unique requirements of a towed array hose. The Navy seeks innovative approaches to providing vibration isolation to TB37 surface ship towed arrays, while reducing or eliminating susceptibility to cutting or puncturing hazards often experienced during towing, deployment, and retrieval operations. Successful solutions would meet all current VIM requirements related to passing data (6 optical single mode fiber data paths at ~ 100 Mbps) and power (500 Vdc, 2.5 A) and attenuating low frequency mechanical vibrations by ~ 20 dB. The proposed solution must also meet all form-factor and environmental requirements (MIL STD 810G) such as array diameter (3.5 inches), working tensions up to 5000 pounds, compatibility with towing at sea for a five-year period, and prevent seawater from migrating from the exterior to the interior of the hose over the five-year life. The solution should either improve the hose resistance to cuts, abrasions, and punctures; or otherwise eliminate the consequences of said damage to the structural integrity of the primary seawater seal by sealing the cut or tear. Cut resistance will be evaluated using ASTM F2992-15 (information available online) or an equivalent test developed by the Government. Any solution for sealing will be evaluated using environmental testing (temperature and pressure IAW MIL-STD-810Gand under tow with a full array system). Water intrusion will be evaluated using the insulation resistance between the wires in the VIM. The Phase II effort will likely require secure access, and NAVSEA will process the DD254 to support the contractor for personnel and facility certification for secure access. The Phase I effort will not require access to classified information. If need be, data of the same level of complexity as secured data will be provided to support Phase I work. 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 contract as set forth by DSS and NAVSEA 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 advance phases of this contract. 

PHASE I: Develop a concept to address the key design elements of the cut-resistant VIM hose. The approach will show it is feasible for meeting current VIM hose standards as described in the description. Feasibility will be demonstrated by analysis and modeling of key elements. The Phase I Option, if awarded, will include the initial design specifications and capabilities description to build a prototype in Phase II. Develop a Phase II plan. 

PHASE II: Based on the results of Phase I modeling and the Phase II Statement of Work (SOW), design, develop, and deliver a prototype cut-resistant VIM hose that demonstrates resistance to damage based on the requirements listed in the Description. The demonstration will take place at a Government- or company-provided facility. The Navy will also conduct its own independent functionality and environmental testing of the prototype, which requires delivery to the Government of one VIM hose example for testing. Prepare a Phase III development plan to transition the technology for Navy production and potential commercial use. It is probable that the work under this effort will be classified under Phase II (see Description section for details). 

PHASE III: Assist the Government in transitioning the fully functional, cut-resistant VIM hose to allow for further experimentation and refinement, and finally to Navy use. Support installation of the VIM hose in a TB37 surface ship fat-line towed array and provide assistance during laboratory and shipboard test events. A cut-resistant towed array hose would be of great interest to the seismic oil exploration industry. Increasing the reliability/availability of towed systems in high-clutter areas, such as commercial fishing areas, would reduce costs for these companies by lowering their required spares and increasing the useful life of their existing arrays. 


1: Lemon, S. G. "Towed-Array History, 1917-2003." IEEE Journal of Oceanic Engineering, Vol. 29, No. 2, April 2004, pages 365-373.

2:  Urick, R. J. "Principles of Underwater Sound for Engineers." New York: McGraw-Hill Book Company, 1967.

3:  3. Burdic, William S. "Underwater Acoustic System Analysis." New Jersey: Prentice-Hall, Inc., 1991.

KEYWORDS: TB-37; Vibration Isolation Module (VIM); VIM Hose; Acoustic Self-noise; Low Frequency Mechanical Vibrations; Towed Array Sensors 


Michael Williams 

(401) 832-5184 

Robert Cutler 

(401) 832-8229 

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