Harbour Tug Hybrid Retrofit

Pain Point


A port operated several high‑power tugs for ship assist and escort duties. Tug operations feature frequent starts/stops and short high‑load periods. Diesel engines run inefficiently, resulting in extremely high fuel consumption, black smoke, and noise affecting the dock environment. The port was pursuing a green port rating with mandated carbon reduction.

 Solution

We designed a parallel hybrid system for the tug:

• LanghESS‑S1 modular battery system (sized for peak power demand)

• Permanent magnet motor (reversible as generator/motor)

• Smart energy management system (auto‑switches between electric, hybrid, and charge modes)

• Shore‑side fast charging interface

The motor is inserted between the diesel engine and propeller. Batteries provide instant peak power, allowing the diesel engine to run at lower RPM or shut down completely during electric standby.

Value Delivered

• 25–35% fuel savings – Batteries shave peaks and fill valleys during towing; standby and low‑speed manoeuvring are fully electric.

• Dramatically lower emissions – No black smoke, improved port air quality, meeting green port criteria.

• Faster response – Instant torque from the motor improves manoeuvrability and reduces ship turnaround time.

• Extended engine life – Reduced high‑load operation lowers overhaul frequency.

• Noise reduction – Near‑silent electric mode improves crew working conditions.