SCHOTTEL Hybrid Drive Solution for KOTUG’s Methanol-Fuelled Tugs

[By: SCHOTTEL]

SCHOTTEL is equipping the world's first large purpose-built dual-fuel methanol escort tugs based on the Robert Allan Ltd. RASalvor 4400-DFM design for towage company KOTUG Canada with rudderpropellers featuring the mechanical hybrid solution SYDRIVE-M. The tugs – to be named SD Aisemaht and SD Qwiy Aanitsa Sarah – are currently in the final stages of construction at Turkish Sanmar Shipyards. After their completion in Q3 2025, they will service Canada’s Trans Mountain Expansion Project, escorting laden crude oil tankers from the outer harbour limits of the Port of Vancouver to the open Pacific Ocean through the commercial shipping lanes of the Salish Sea.

“We are pleased to move forward and implement these newbuild green solutions to the Trans Mountain Expansion Project enhanced tug escort program,” says Laurens Korporaal, Business Development Manager, KOTUG Canada. “These tugs, propelled by modern climate-friendly SCHOTTEL propulsion systems, exhibit the aspirations of the British Columbia tug market to improve environmental performance of shipping activity and advance new solutions to local and global environmental challenges.”

Impressive bollard pull of 120 tonnes
In order to provide the best performance for their tasks, the tugs require a propulsion system that offers both transit efficiency and high bollard pull. For this purpose, the vessels are each equipped with two SCHOTTEL RudderPropellers type SRP 710: The 360-degree steerable SRP combines bollard pull with high propulsion efficiency and provides the ships with excellent manoeuvring capabilities. In addition, the tugs are also each fitted with a SCHOTTEL TransverseThruster type STT 170. With this propulsion system, the vessels will achieve a free sailing speed of up to 14 knots and an impressive bollard pull of over 120 tonnes, making them the most powerful escort tugs in Canada.

Less fuel consumption due to SCHOTTEL SYDRIVE-M and graphene paint Since the tugs operate along the shores of the Salish Sea and the respective Salish Sea communities including the Sc'ianew First Nation, they have to meet special environmental requirements in terms of their equipment, which is also reflected in the chosen propulsion system: To further optimize fuel savings and reduce underwater radiated noise, all four of the ordered SRP azimuth thrusters feature SCHOTTEL SYDRIVE-M. The mechanical hybrid solution allows the two thrusters
per vessel to be driven together by only one of the main engines. This reduces main engine operating hours, resulting in lower maintenance costs as well as less fuel consumption and lower emissions. Furthermore, the system needs no additional electrical components. In addition, the hulls of both tugs are coated with a graphene paint to minimize biofouling and enhance the hull smoothness of the vessels which reduces underwater radiant noise and makes the vessels more fuel efficient.