Arc has started the battery-electric conversion of Harbor Sentinel, a 50-foot harbour tug owned and operated by Pacific Maritime Group (PMG), in a project supported by the Port of Long Beach’s funding programmes.
Project details
According to MarineLink, Arc has begun the engineering phase of the conversion, working specifically on adapting Harbor Sentinel’s propulsion and energy systems to battery-electric operation while retaining her harbour-towing role. The work represents a vessel-level application of battery-electric technology aimed at reducing emissions and operational fuel use aboard a compact, harbour-class tug.
The conversion will focus on replacing or supplementing the existing propulsion plant with battery energy storage and associated power electronics, together with integration of controls that suit harbour towing and manoeuvring duties. Arc’s engineering scope, as reported, is the technical design and systems integration required to ensure the vessel meets the operational requirements set by her owner, PMG.
Funding and partners
The project is supported by funding from the Port of Long Beach through its Technology Advancement Program, often shortened to TAP, and the port’s SWIFT Programme, which have been cited as enablers of the engineering work. Those programmes are described in the report as providing financial support to advance low- and zero-emission technologies in port operations and related vessels.
Pacific Maritime Group continues as the vessel owner and operator responsible for Harbour Sentinel’s return to service once conversion work is complete, while Arc serves as the marine-technology company leading the technical conversion effort. The collaboration positions a private operator, a specialist technology provider and port-directed funding in a single conversion project, reflecting a partnership model increasingly used in harbour decarbonisation efforts.
Industry significance
Converting an existing 50-foot harbour tug to battery-electric propulsion is indicative of a pragmatic approach many operators are taking to reduce emissions without immediately replacing fleets with newbuild zero-emission vessels. Such retrofits can permit owners to retain proven hulls and operational practices while introducing electric powertrains that alter fuel consumption, emissions profiles and maintenance needs.
The engineering phase reported by MarineLink is a critical step because it establishes whether an individual vessel’s layout, electrical load profile and duty cycles can be accommodated by battery storage and power-management systems without compromising reliability. Successful conversions of harbour tugs could accelerate uptake if they show clear operational and lifecycle benefits under typical harbour towing and manoeuvring schedules.
The conversion of Harbor Sentinel, as reported, will be watched by harbour operators and ports that are weighing capital and operational trade-offs between new zero-emission tugs and the retrofitting of existing vessels. The involvement of port funding programmes in this project underlines a continuing interest by port authorities in underwriting demonstration projects that may lower barriers to wider adoption of low-emission technologies.
MarineLink first reported the development on 5 November 2026, identifying Arc as the engineering lead and Pacific Maritime Group as the owner-operator whose 50-foot harbour tug is to be converted with support from the Port of Long Beach. The report frames the work as an example of port-backed technology advancement applied to vessel decarbonisation.
The outcome of Arc’s engineering work on Harbor Sentinel will determine the technical feasibility and potential replicability of similar conversions elsewhere, and stakeholders in port operations and harbour services will likely monitor results for lessons that could inform future investment and policy decisions.