STORY Commercial Marine

Repowering on Lake Thun

Posted on September 24, 2018 by Miriam Jesenik, Images by Robert Hack, Christoph Hurni

In summer, it plies the waters, taking tourists from Thun to Interlaken and back. In the winter, the Berner Oberland was fitted with two new mtu engines.
Lake Thun, Switzerland

Lake Thun is a much loved tourist destination in Switzerland and very lively in the summer months. It is also the place where Swiss transport company BLS AG runs a shipyard. The shipyard reaches its peak of activity in the winter, when the holidaymakers have gone home. This winter, it gave the Berner Oberland, a motor vessel that plies the waters between Thun and Interlaken, a major overhaul, which included repowering it with two new mtu engines.

It is a warm summer's day in Thun. A gentle breeze blows across the lake, the sun's rays glisten on the water, and small fluffy clouds occasionally float across the blue sky. In the distance, the jagged contours of Bern's three grand peaks – the Eiger, the Mönch and the Jungfrau –  and next to them the Blüemlis mountain range, stand out on the horizon. They are so clear-cut they seem almost tactile. Meanwhile, on the shore, holiday makers in bermudas,  summer dresses and sunhats stroll to and fro, enjoying the scenery and the sunshine, and pile into the pleasure boats waiting on the  lake.

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Flash back a few months to a much wintrier scene:  only a few shafts of sunlight are able to penetrate the thick blanket of grey sky, the air is very cold, and the mountain peaks have all but disappeared behind the mists. The lake seems a desolate place, but when the sunlight does hit the water, the frozen algae produce an amazing turquoise glow, almost like the sea in the Caribbean.

New engines for MS Berner Oberland

Transport company BLS AG has its new shipbuilding factory in a bay of Lake Thun not far from the town. The factory is a wooden construction completed just at the beginning of the year and replaces the former dockyard building which had reached the grand old age of 111. It was in this building that the oldest vessel circulating on Lake Thun, a paddle steamer named DS Blümlisalp, had been originally assembled.  Today, the new dockyard construction still emanates the whiff of wood and fresh paint and in the middle in the dry dock, stands the MS Berner Oberland. After 21 years of service, the vessel is to receive a new wheelhouse, a new stern bridge, new propeller shafts, and up-to-date electronics. The existing engines are from Detroit Diesel and have 24,000 hours runtime on the clock. These are to be replaced by twin 12V 2000 M61 units from mtu.  “We're fans of mtu,” says Hans Stucki, who manages the BLS AG dock. BLS operates a 10-vessel fleet on Lake Thun and Lake Brienz, and the Berner Oberland is the first in the fleet to be repowered with new engines. The ferry MS Brienz, that shuttles between Interlaken and Brienz, already has twin mtu units on board. “With mtu engines, your service interval can be longer than 1,200 hours. No other engine-builder can match that,” pointed out Stucki.  For a cosmetic face-lift, the vessel will still have to wait a few years until enough funds are available for re-painting the exterior, re-furbishing the interior and replacing the green carpets. 

Shipyard's peak of activity in the winter

MS Berner Oberland has been in the dry dock since the beginning of January. “The crew of the Berner Oberland doesn't holiday in the summer,” said Stucki,  “but with me it's the other way round.  In the winter, I'm often working a 10-hour day.” His alarm goes off early, since he has to be at the shipyard for 6:20. As shipyard manager, he takes responsibility for some 40 members of staff. When they arrive at 7:20, Stucki has done all the preparations and the groundwork and knows exactly what jobs have to be done that day and by whom. When his people clock out again at 16:00, his labors are not quite over – he will be kept busy until at least five o'clock, supervising external firms who come in to work on things like hydraulics or installing CO2 fire extinguishers.  Only then can Stucki call it a day. “I chalk up more than a month of overtime in the winter months,” he says, but with a shrug.

Start of season in May

The biggest challenge during installation of the engines was the fact that there were no ship drawings available that were dimensionally correct. That meant that no precise planning could be done for lift-in of the new engines as long as the old engines were in situ. Furthermore, to get the new engines through the hatch, it turned out that they would have to be partially disassembled by disconnecting them from the gearbox. Re-assembly took place in the engine room. All in all, engine installation and commissioning took around two weeks. The next step was functions-testing of the engine and mtu Blueline ship automation system. To do this, the dry dock, which is 68m wide and 16m long, had to be flooded with 4.5 million liters of water – roughly equivalent to 30,000 filled bath tubs.

Now it's the beginning of May, and MS Berner Oberland is back in full-time service, carrying holiday guests to and fro between Thun and Interlaken. The engines clock up around 5 hours' service each day, with extra duty when the ferry is rented for private events in the evening or on bank holidays. Another significant change is the power output of the new engines, which are able to deliver 600 kW instead of the 490 kW provided by the old Detroit Diesel units. This makes ship handling different – and is a point on which the crew will firstly have to be trained.

Point of contact

Miriam Jesenik
+49 7541 90 2974