Hybrid ferry for Turku archipelago

Finland’s first hybrid ferry operates between Parainen and Nauvo

The ferry route between Parainen, Lillmälö and Nauvo, Prostvik in the Turku archipelago is Finland’s busiest. In the mid-2010s, traffic on the ferry route was around 2,400 vehicles a day, and waiting times for the ferry could be rather lengthy.

At that time, the ELY Centre for Southwest Finland and Suomen Lauttaliikenne Oy (Finferries) began to consider whether it would be possible to develop a new, perhaps greener, concept for clearing the queues.

The aim was to alleviate congestion on the ferry route with an environmentally friendly and energy-efficient hybrid ferry that was larger than the previous ferries. Finland’s first-ever hybrid ferry also needed modern ferry harbours to match.

Terramare took up the challenge and built new ferry harbours equipped with transformers. “The hybrid ferry charges its batteries when it is berthed at the quay, even when loading is under way,” says Project Manager Marko Saarelma. “Finally, the batteries are always charged fully during the night. The ferry mainly uses shore power, with diesel electricity as back-up.
The new ferry harbours were built next to the old ones. At one harbour, the distance to the old one was only ten metres,” adds Saarelma.

Communication worked

The Terramare team began construction of the ferry harbours in May 2016 and the work was completed exactly one year later. Work went well – even though ferry traffic continued to run throughout construction.

“We were in constant contact with the ferries to ensure that traffic and construction work advanced smoothly in the best possible way,” says Saarelma.

Finland’s largest road ferry, Elektra, finally started operating in June 2017. The ferry, nicknamed the “Archipelago Tesla”, can carry up to 90 cars at a time, around 40 per cent more vehicles than its predecessor, Sterna, was able to carry.

Streamlining is also enhanced by the hybrid vessel’s deck system, which boosts the efficiency of loading and unloading. Through the electrification project, the hourly capacity of the route has improved by nearly a third (30%), at 15 minutes between sailings.

With the arrival of Elektra, Sterna became the number two vessel, and the former number two vessel Falco became the back-up vessel.

Execution period: 2016–2017

Terramare does what it promises, and you can trust in the quality of the end product. Cooperation is easy, natural and solution-oriented. As a contractor, Terramare is a top professional in its field, a true specialist of marine and foundation construction.”

– Tapani Jaakkola, Civil Engineer, ELY Centre for Southwest Finland