Seaspan Corporation and Technolog have developed a 3,370 TEU feeder vessel design that can operate on LNG and convert to ammonia propulsion within a four-week dry-docking period, according to a case study published by Lloyd’s Register.

The concept has received Approval in Principle from Lloyd’s Register and forms part of a Joint Development Project involving the three organisations. The design targets regional container trades, with provision for 480 reefer units and an approximate range of 5,000 nautical miles on marine gas oil or ammonia, and around 9,000 nautical miles on LNG.

According to the case study, nearly 25% of the global feeder fleet is over 20 years old, creating what is described as a bottleneck of ageing tonnage. The design addresses operational requirements specific to regional trades, including pallet-wide capability for European and Baltic routes, draft restrictions at ports such as Bangkok and Kolkata, and the need for geared vessels in African and South American ports.

The ammonia-prepared configuration includes a containment system that can be adapted through tank coating or materials suited to both LNG and ammonia. Double-walled piping installed during construction supports both fuels with limited modification, while the two-stroke dual-fuel LNG engine provides the basis for later conversion.

The design features a forward wheelhouse for improved visibility and additional cargo capacity, with an aft deckhouse supporting machinery integration. A 1 MW battery system provides peak shaving and bow-thruster support, while propulsion efficiency comes from a gate-rudder arrangement. An optional telescopic Flettner rotor sail is available for further efficiency gains.

Power take-off, power take-in and power take-home functions are incorporated to support fuel efficiency across coastal and variable-load operations.

Lloyd’s Register’s role includes providing Approval in Principle for the concept and assurance on containment readiness, conversion steps and system integration. The classification society also supports verification processes for sustainable-fuel book-and-claim systems.

Peter Jackson, Senior Vice President of Assets and Technology at Seaspan Corporation, stated: “Seaspan and LR have partnered to address important topics for many years, and this is an excellent result of one of those partnerships. Technolog’s input has also provided a creative solution and demonstrated their leadership in the ship design and feeder ship segment.”

Hans-Jürgen Voigt, CEO of Technolog, commented: “What impressed us most was LR’s ability to deliver reliable market trend analysis alongside timely, actionable insights. This allowed us to further refine and enhance our design, ultimately enabling the creation of a ‘best in class’ next-generation feeder vessel.”

The case study notes that transition-ready configurations remain uncommon in the feeder segment, with the design providing a reference for embedding transition planning into new tonnage. The ability to complete conversion within a short dry-docking period is intended to reduce uncertainty linked to fuel-transition timing.

Lloyd’s Register leads the Silk Alliance through the Lloyd’s Register Maritime Decarbonisation Hub and contributes to initiatives including ZEMBA, while hosting feeder-focused discussions through the Containership Forum.