Improved Towed Array Acoustic Hose

Navy SBIR 22.1 - Topic N221-055
NAVSEA - Naval Sea Systems Command
Opens: January 12, 2022 - Closes: February 10, 2022 (12:00pm est)

N221-055 TITLE: Improved Towed Array Acoustic Hose

OUSD (R&E) MODERNIZATION PRIORITY: General Warfighting Requirements (GWR)


The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Develop a towed array acoustic hose that prevents permanent hose deformation (creep), reduces water permeability, increases resilience against physical damage, and increases useful life.

DESCRIPTION: An improved hose for the acoustic modules of towed arrays for Navy submarines and surface combatants is desired. Current commercial state of the art for hosing on these acoustic modules leads to hoses that are often damaged by 1) marine life (e.g., shark bites), 2) fishing gear such as hooks and nets, and 3) typical wear and tear from vibration and torsion during normal operations. Further, there is reason to expect that it could be possible to improve the acoustic performance of the hose over the existing state of the art, which would enhance the ability of the towed array system to detect acoustic signals.

Towed arrays are streamed in the ocean by Navy combatants to detect underwater acoustic signals. Current towed array acoustic hoses are fluid-filled thermoplastic polyurethane (TPU) extrusions that contain towed array sensors and electronics. These hoses perform various functions to optimize towed array functionality and performance. The hose material provides some isolation from noise through a variety of factors (such as modulus, loss-tangent, material selection, and reinforcement design), protects the array from the surrounding environment, relieves some mechanical load on the array internal components during handling, storage, and shipping, and generally functions as the primary physical interface between the towed array and the environment. The hose typically experiences significant mechanical, environmental, and chemical stresses like high pressures, a wide range of temperatures, tension, torsion, vibration, exposure to seawater, isoparaffinic solvents, and so on. In addition to these harsh conditions, the hose is also often exposed to free floating fishing gear (known as "ghost fishing"), marine animal attack, abrasive surfaces, and other mechanically harsh situations.

The solution sought is expected to endure the aforementioned conditions for a period of at least 5 years before requiring replacement for any reason presuming a maximum of 25% array deployment at a maximum average of 15 knots across the 5 year period. The hose should resist physical damage due to sharp objects or abrasion (be at least 50% more cut-resistance than current hoses). The hose should reduce the ability of water to permeate the hose by at least 3 orders of magnitude over a 1-year period of immersion in sea-water. The hose should reduce mechanical creep by 2 orders of magnitude compared to legacy towed array hoses when exposed to axial loading for a period of up to 3 consecutive months.

In addition to achieving these requirements, the towed array hose must achieve the basic functions of legacy towed array hoses (listed below) and must not negatively impact towed array acoustic performance.

Baseline Requirements:

  • Temperature: -28ºC to 60ºC
  • Pressure: -5 to 1200 psi
  • Vibration: MIL-STD-167A
  • Chemical:
    • 5-year exposure to seawater
    • 5-year exposure to ISOPAR L and/or ISOPAR M
  • Suitable for reinforcement with various cords or yarns, such as Polyester, Kevlar, and Vectran
  • Suitable for outside diameters of 1.1" to 3.5"
  • Suitable for lengths up to 200’
  • Suitable for hose wall thicknesses of 0.11" to 0.375" with a 125 micro-inches RMS surface finish
  • Suitable for wrapping on drums with a d/D ratio of 1:24
  • Suitable for achieving a leak-proof swaged or crimped termination
  • Suitable for filling to a "firm and round" condition using internal pressure and maintaining that condition for 90 days
  • Must not negatively impact towed array acoustic performance

The government will provide support for testing prototype assemblies in unique environmental testing facilities as required (such as towed array handling systems, long tension beds, large environmental chambers, etc.).

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 Counterintelligence Security Agency (DCSA), formerly the Defense Security Service (DSS). The selected contractor 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 DCSA 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 for an Improved Towed Array Acoustic hose that meets the requirements in the Description. Demonstrate the feasibility of the approach based on analysis, modeling, simulation, and evaluation. Demonstration must show an understanding and estimation of the critical performance factors as set for in the Description and explains that the approach is feasible. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build full scale prototype solutions in Phase II.

PHASE II: Develop and deliver a prototype Improved Towed Array Acoustic hose based on the results of Phase I and the parameters in the Description. A number of prototype hose samples may be required for testing and evaluation to be conducted. The system will be evaluated, tested, and certified by the government.

It is probable that the work under this effort will be classified under Phase II (see Description section for details).

PHASE III DUAL USE APPLICATIONS: Assist the Government in transitioning the technology to Navy use. This will include experimentation and refinement of the prototype to qualify the technology for use on towed arrays. The government will provide the performer access to a Navy ship or research vessel where the final system validation and performance verification will be conducted. Support installation and removal from a test platform and assist in data analysis and interpretation. Existing data will be used to verify the measurements and accuracy of the system.

This system would prove useful for oceanographic research, oil and gas exploration, and potentially any industry where rugged, flexible, chemically resistant hoses are used, such as transportation, industrial plants, and automotive.


  1. Lemon, S. G. "Towed-Array History, 1917-2003", IEEE Journal of Oceanic Engineering, Vol. 29, No. 2, April 2004, pages 365 – 373, Locate libraries that hold this title at
  2. Burdic, William S. "Underwater Acoustic System Analysis", New Jersey: Prentice-Hall, Inc., 1991. Locate libraries that hold this title at
  3. "AN/SQQ-89(V) Undersea Warfare / Anti-Submarine Warfare Combat System," Navy Fact File.

KEYWORDS: Towed Array; Hose Deformation; Towed Array Sensor; Cut-Resistance; Water Permeability; Mechanical Creep


The Navy Topic above is an "unofficial" copy from the overall DoD 22.1 SBIR BAA. Please see the official DoD Topic website at for any updates.

The DoD issued its 22.1 SBIR BAA pre-release on December 1, 2021, which opens to receive proposals on January 12, 2022, and closes February 10, 2022 (12:00pm est).

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