Design for the Purpose-Built, National Security Multi-Mission Vessel at Maine Maritime Academy

Abstract: The U.S. Department of Transportation Maritime Administration (MARAD) provides training ships to each of the six state maritime academies. Currently, MARAD is replacing the training ship at five of the academies with new, state-of-the-art, purpose-built vessels. The new National Security Multi-Mission Vessels (NSMV) will be part of the National Defense Reserve Fleet and serve multiple purposes. They will provide state-of-the-art academic training platforms for the academies and provide the U.S. with ships to support disaster response, such as after hurricanes, and other critical national needs. Construction of the first NSMV began in 2019 and the fifth NSMV is scheduled for 2026.
Since its inception in 1941, the Maine Maritime Academy (MMA) in Castine, Maine has had 14 training ships, each playing an integral role in the academic programming and preparation of students in becoming mariners. MMA is slated to receive the third NSMV as its 15th training vessel in 2025. Compared to MMA’s current training ship, the NSMV is approximately 25 feet longer, 33 feet taller at the wheelhouse, and draws approximately 8 feet less draft. Being part of the National Defense Reserve Fleet, MARAD requires the academies to meet heavy weather mooring requirements for a Category 1 hurricane. With the larger ship, MMA’s existing timber pier and concrete dolphins are not adequate for mooring and berthing the NSMV. In designing a new pier and dolphins for the NSMV, the hull curvature and designated fender contact areas proved challenging for MMA’s 11-foot daily tidal range and the design sea level rise. Other design challenges included the constrained site conditions and littoral rights for laying out the mooring dolphins adjacent to the Town’s public dock and residential properties; the provided heavy weather mooring plan not being fully compatible with the mooring dolphin layout; and the soil profile with shallow bedrock at the site.
In addition to the design parameters and site conditions, other factors influenced the pier and dolphin design. MMA’s operational needs during construction dictated a longer pier than their existing pier. Having experienced waterfront changes each time MMA’s training ship has been replaced, the rural community of 1,300 people and the town’s boards were very interested and forthcoming with their feedback, which led to iterations for siting the mooring dolphins before receiving written approval from the adjacent properties and land use board for regulatory permitting at the local and state levels.
This paper will present the challenges for MMA’s new pier and dolphins for the NSMV training ship. It will highlight the technical and non-technical factors which influenced the design and layout, as well as the impacts of a very condensed design and permitting timeline necessary for the NSMV delivery schedule.

How does this project / topic contribute to the advancement of the industry and profession?: This project contributes to the advancement of the industry and profession through the lessons learned regarding the unique challenges of designing a pier for a single vessel with very specific parameters that are not fully compatible with the site’s tidal range or standard operational practice to vacate the berth for Category 1 hurricane conditions.

Does the project / topic implement new and innovative techniques, materials, technologies, and delivery methods?: The project required coordination with U.S. Department of Transportation Maritime Administration (MARAD) and the shipbuilder for the design ship parameters and varying allowable hull pressures along the length of the ship and for confirmation that the ship had capacity for the heavy weather mooring plan modifications that were necessary for the site limitations on siting the dolphins. The project also incorporated both pre-cast and cast-in-place concrete pier framing to accommodate pile configurations and construction timelines.

What was the most challenging aspect of your project / topic and how did you handle it to ensure success?: The most challenging aspects of the project related to the requirements for the NSMV mooring and berthing and the ship’s hull pressure and curvature for pier fendering. These challenges were resolved by the design of the new pier and dolphins and by a non-conventional, hybrid fendering system. The fenders consisted of cone fender panels and foam-filled fenders.

Who is the target audience for this paper?: Designers, owners, and shipbuilders.