First new Saimaa tugboat in over 60 years under design

Aalto University is designing the first modern inland waterway tugboat for the Vuoksi river basin, replacing vessels over 60 years old currently used in log driving.

The last new tugs for the Vuoksi system were built in the 1970s, and no new passenger or cargo vessels have since appeared on Lake Saimaa, according to Järvi-Suomen Uittoyhdistys log driving chief Esa Korhonen.

“The positive outlook for log driving encourages decisions to bring new tugs to Saimaa in the coming years,” Korhonen said.

The new Saimaa tug will be nearly flat-bottomed, 22.5 metres long, 7 metres wide, with a 2.4-metre draft allowing navigation on shallow routes. Its 735 kW engine can tow rafts over a kilometre long, carrying 400 truckloads of wood or 1,200 bundles.

Aalto University will complete a modern log-driving tug design this autumn as part of Ville Haikonen’s thesis. Haikonen said the 60-year gap since the last replacements means starting from scratch, with emphasis on energy efficiency, production costs, and crew working and living conditions.

Maritime expert Jarkko Toivola, Haikonen’s thesis supervisor, called the Saimaa tug unique. “This type of log driving isn’t practiced anywhere else in the world in the same way,” he said.

The tug’s low speed but high continuous power and shallow-water operation set it apart. Its flat-bottom design reduces construction costs by simplifying the hull geometry, eliminating the need for complex metal bending.

The vessel will serve multiple roles beyond log driving, including icebreaking, channel maintenance, and oil spill response. Its command bridge can be hydraulically raised by two metres for barge pushing, and its large aft deck can accommodate a 10-foot shipping container for equipment.

The main engine will be dual-fuel, capable of running on diesel, methanol, or hydrogen. Crew accommodations will include individual cabins of about seven square metres, as current vessels can operate continuously for up to two weeks.

About 15 tugs are needed for Saimaa, towing log rafts from the northern Vuoksi basin to southern Saimaa, with towing distances over 450 kilometres. Last year, all forest industry companies in the Saimaa region returned to log driving, with rafts now towed to five mills as part of climate programmes to reduce carbon footprints and costs in raw wood transport.