DON26TZ02-NV020 TITLE: Submarine Top-side Anti-Slip Anti-Foulant

COMPONENT TECHNOLOGY PRIORITY AREA(S): Advanced Materials; Sustainment

PROJECTED CMMC LEVEL REQUIREMENT: Level 2 (Self)

OBJECTIVE: Develop a non-toxic, high-friction anti-fouling coating for submarine topsides that will not be damaged by alternating wet-dry cycles, solar radiation, or atmospheric exposure. The antifouling coating must also be tough enough to withstand foot and cargo traffic.

DESCRIPTION: Anti-fouling paints and coatings are applied to submarines, ship hulls, and acoustic sensors to inhibit the growth and accumulation of unwanted marine life ("biofouling"; e.g., barnacles, tube worms, algae biofilms, etc.). Biofouling increases surface drag and creates noisy flow conditions. Some anti-fouling materials contain poisons (biocides) to discourage the unwanted marine growth while others (foul release type coatings) form extremely slippery surfaces that prevent marine organisms from attaching strongly to their surfaces. Some newer coatings utilize both mechanisms in combination to discourage/prevent biofouling.

Several challenges arise with respect to the topsides of submarines. Humans need to walk on the topside of submarines during certain situations. Slippery anti-fouling coatings pose a significant safety risk, as they can lead to falls overboard and potentially serious injuries. The coating must also be mechanically robust enough to not be damaged or de-bonded from protected surfaces due to normal foot traffic and equipment/cargo placement. Currently used anti-fouling paints and coating present both immediate and long-term challenges. If they contain biocides, toxic residues can be tracked inside the submarine, posing a health hazard to the crew. Additionally, the reliance on toxic components raises concerns about the future availability and cost of these materials. Finally, the topside environment is an alternating wet/dry environment, so any antifouling paint/coating/material use there would need to survive desiccation and periods of time when it would be above the waterline for days or months without experiencing a significant drop in effectiveness when it is once again underwater. During the time it is above the waterline/out of the water, the paint/coating/material would need to survive exposure to air and direct sunlight. There is no commercially available solution to this problem.

The Navy is seeking novel anti-fouling paints, coatings, or materials and application methods for the anti-fouling products for use on submarine topside surfaces. These solutions must effectively inhibit marine growth while maintaining the flow conditions associated with propulsion efficiency and noise due to turbulent boundary layers, including minimizing drag and turbulent flow at operational speeds. The solution must also allow sailors to maintain steady footing when the topside of the submarine is awash with sea water. Exact characteristics of the submarine hull surface would be considered controlled unclassified information, which will be shared with Phase I performers after they are under contract. The solution(s) will be a useable topside coating that minimizes biofouling on topside surfaces while the submarine is submerged. After it is initially applied, the solution should remain bonded to the protected surfaces and be able to discourage or prevent biofouling for up to 6-8 years without any major maintenance or routine cleaning. Standard Navy requirements for adhesion, color, performance, and durability will be invoked as the candidate materials advance.

The Navy seeks this innovation to leverage advancements in non-toxic materials, addressing the long-standing need for safer alternatives in applications currently reliant on toxic substances. Recent advancements in marine antifouling strategies include bioactive antifoulant mechanisms, self-polishing antifouling mechanisms, surface wettability mechanisms, photocatalytic bactericidal mechanisms, and biomimetic antifouling mechanisms. Successful prototypes will be useful for unmanned, undersea vehicles that are handled/retrieved by ship’s crews and stored on deck between missions, as well as the Navy’s intended target of submarine topside surfaces.

PHASE I: Develop a concept for a non-slip, anti-fouling coating that demonstrates it feasibly meets the requirements of the Description. Feasibility will be demonstrated through modelling and analysis, and should include a plan for synthesis of the material(s). The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a prototype solution in Phase II.

PHASE II: Develop and deliver a prototype non-toxic, high-friction anti-fouling coating based on the results of Phase I. Demonstrate through a comprehensive test and evaluation program that the solution meets the parameters of the Description. This will encompass physical testing on representative hull sections provided by the government. Initial demonstrations may be performed on painted metal and fiberglass. Prototype effectiveness should also be demonstrated through computational modeling and analysis.

PHASE III DUAL USE APPLICATIONS: Assist the Navy in transitioning the prototype to Navy use. Collaborate with the Navy on the transition and implementation of the technology. Continue development to initially lead the company through material and application system certification for Navy use.

The Navy anticipates significant commercial opportunities for this technology in the maritime shipping and cruise industries, beyond its application on submarine topsides.

REFERENCES:

1. Li, Sheng et al. "Marine antifouling strategies: Emerging opportunities for seawater resource utilization." Chemical Engineering Journal, Volume 486, 2024, 149859. ISSN 1385-8947. https://doi.org/10.1016/j.cej.2024.149859
2. Dafforn, Katherine A. et al. "Antifouling strategies: History and regulation, ecological impacts and mitigation." Marine Pollution Bulletin, Volume 62, Issue 3, 2011, pp. 453-465. ISSN 0025-326X. https://doi.org/10.1016/j.marpolbul.2011.01.012
3. Zang, Xuerui et al. "Non-toxic evolution: Advances in multifunctional antifouling coatings." Materials Today, Volume 75, 2024, pp. 210-243. ISSN 1369-7021. https://doi.org/10.1016/j.mattod.2024.03.018

KEYWORDS: Anti-fouling; marine growth inhibitors; health hazard to Submariners; turbulent flow; minimizing drag on Submarines; submarine topside

TPOC 1
Thomas Ramotowski
(401) 832-5111
thomas.s.ramotowski.civ@us.navy.mil

TPOC 2
Katharine Tarasuk
(401) 832-8442
katharine.l.tarasuk.civ@us.navy.mil