VESSEL REVIEW | Estelle – Autonomous electric ferry enters service in Stockholm

Norwegian transport company Torghatten and compatriot technology firm Zeabuz have handed over an autonomous electric ferry to Torghatten's Swedish subsidiary Zeam.

Named Estelle after the eldest grandchild of Sweden's King Carl XVI Gustaf, the 12.2- by 5.2-metre, 18-tonne ferry was built at the Hyen facilities of Norwegian shipbuilder Brødrene Aa. It is fitted with an advanced autonomous navigation system developed by the Norwegian University of Science and Technology and a propulsion system powered entirely by electricity supplied via an array of onboard solar panels. The use of electrical propulsion is in line with the Stockholm local government's aim of ensuring all maritime traffic in or near the city is fully-electric by 2030.

The propulsion system includes four Fischer Panda 10kW motors while the electricity collected by the 16 Suncel solar panels is stored in two ZEM 94kWh high-voltage batteries and two Anda Olsen 8kWh low-voltage batteries.

The ferry can accommodate 25 passengers plus bicycles on an open, covered deck with boarding and disembarking to be done via the bow and the stern. The solar-powered propulsion will meanwhile ensure a maximum of 15 hours of continuous operation, allowing multiple trips to be completed without any adverse environmental impact. The solar panels also provide power for the Simrad radar, cameras, collision avoidance sensors, and other electronics.

Space is also available for a Viking lifeboat for use in an emergency.

Estelle already commenced operational sailings in Stockholm in June. Four departures are scheduled for each of 15 hours that the vessel is in operation every day, though Torghatten expects the number of hourly departures to increase to eight in the coming months.

An operator will be on board during the initial sailings to control the vessel via a helm station in the wheelhouse. The long-term objective is for sailings to be conducted autonomously under the supervision of shore-based personnel.

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