Theseus is a 150-bed housing project adjacent to the Port of Chelsea, MA, that repurposes cargo holds from decommissioned bulk-carrier ships, which are typically retired after just 25 years. The project transforms maritime steel infrastructure into resilient, occupiable superstructures. Suspended floor plates keep the ground open for communal use, creating a floodable, adaptable civic space. The structural logic allows the units to contain no structural walls, which offers elasticity. Residents can open operable party walls to expand or merge households, adapting to shifting domestic needs. The five-building complex addresses climate adaptation, material scarcity, and long-term housing stability. By reusing locally sourced steel and integrating public programming, Theseus reframes housing as long-term civic infrastructure that is scalable to other port cities. The project proposes a new architectural typology rooted in industrial heritage, designed not just to shelter but to support life, work, and community over time.