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sts.components.contact.mr.placeholder Sebastian Webel
Mr. Sebastian Webel

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Pictures of the Future
The Magazine for Research and Innovation
 

Electric Mobility

Quiet Cruising on Königssee

Electric boats glide noiselessly on the waters of southern Bavaria’s Königssee thanks to motors from Siemens.

For more than 90 years, electric motors from Siemens have powered boats on Bavaria’s Königssee. Built in 1958, the boats’ drive systems have been providing silent service for a long time. Soon, the systems will be replaced by replicas of the same model.

Siemens engineer Klaus Hunsicker, 55, is welcomed by innumerable flags as he arrives in Schönau on Königssee (king’s lake) in Bavaria. He makes his way through the village’s pedestrian zone, passing shops offering traditional Bavarian costumes and souvenirs. The air smells of freshly baked pretzels. As Hunsicker walks, he begins to catch glimpses of world-famous Königssee. He finally reaches the emerald-green lake, which extends through the valley like a fjord, surrounded by steep cliffs and dominated by 2,700-meter-high Mount Watzmann. The lake, which is almost eight kilometers in length and up to 190 meters deep, contains more than 500 million cubic meters of potable water.

Hunsicker is on a special mission. Several new electric motors are needed for the fleet of ships operated by Bayerische Seenschifffahrt GmbH — the lake’s transport company. The challenge for Siemens is that the new motors should be the same as the 1958 models, which the company produced especially for Königssee. That’s why Hunsicker has come here today. As director of a Siemens repair center, Hunsicker specializes in replica motors, a career that takes him all over the world. In the dockyard next to the lake, Hunsicker meets Michael Brandner, who manages the fleet’s 18 electric boats and is responsible for their upkeep. 

Prince-Regent Luitpold of Bavaria feared that the noise created by combustion engines would scare off wildlife in his hunting grounds alongside the lake.

Siemens motors have been powering electric boats on Koenigssee since the beginning of the 20th century. Before then, passengers traveled in rowboats steered by boatmen known as "€œSee-Knechte"€ (lake servants). The electric boat era was made possible by the railroad, which was completed in 1909 but has since been decommissioned. The railway recharged the boats’ batteries. Back then, Siemens not only supplied the trains, it also supplied the technology for the Gartenau power plant near Berchtesgaden. In 1909 the decision to equip the boats with electric drives was not prompted by environmental considerations. Instead, Prince-Regent Luitpold, who ruled Bavaria at the time, feared that the noise created by combustion engines would scare off wildlife in his hunting grounds alongside the lake. That'€™s why he was very much in favor of procuring electric boats that would travel noiselessly on the lake.

The lake'€™s electric era commenced with the Akkumulator, an electric boat  supplied by the Siemens-Schuckert plants. It was followed by additional boats, all equipped with electric motors from Siemens. The boats were a big success, thanks to their reliability, low operating costs, and lack of emissions. Today, the boats are still powered by 110-volt motors manufactured in 1958. The boats have an output of around nine kilowatts and an average speed of 12 kilometers per hour. Each boat travels about 120 kilometers per day of operation, consuming almost 80 percent of its battery capacity in the process.

“We always know how to manage,” says Brandner. “Our familiarity with the motors is passed on to each new generation, and we even installed the old motors into our new boats.” The boats are serviced in Bayerische Seenschifffahrt’s own dockyard, which has been building the vessels since 1983. However, as a result of the growing number of visitors, the Königssee fleet has repeatedly reached its capacity limit. “That’s why none of the motors are allowed to stand still for even a minute,” says Brandner, who has been working for Bayerische Seenschifffahrt for the past 25 years.

Caring for a 56 Year-Old Electric Motor

Brandner leads Hunsicker through the lakeside boathouses until they reach the “patient.” It is a typical representative of the Königssee fleet, measuring 20 meters by 3.5 meters. It is handmade out of precious wood. Inside, up to 93 passengers can sit on 1920s-style wooden benches with red cushions made by Bayerische Seenschifffahrt’s own upholstery firm. Brandner raises a big lid to reveal the boat’s “heart,” a Siemens electric motor. Hunsicker’s delight at the site of the motor is plainly visible. “You can’t buy something like this ready-made,” he says. Before coming to Königssee, he held several phone conferences with Brandner, examined old plans and data sheets, and studied photographs of the electric motor’s technology.

He believes it’s only natural for Siemens to manage its technological heritage — even for small orders. “No other company has the know-how to replicate a 56 year-old electric motor. That makes us special,” says Brandner with pride. “We’ll once again have a motor that perfectly fits the existing installations. It would be much more expensive to replace the electronics than to replicate the motor. Today, comparably powerful motors are only about the size of a shoe box, so they aren’t compatible with the electronics in the existing fleet.”

The new electronic systems will therefore be designed for the old motors, which are much bigger than today’s electric drives. In addition, the old model motors are less complex than new ones, which is why they can be maintained by Bayerische Seenschifffahrt’s own electricians in Schönau. This is an important consideration for the Königssee fleet, because breakdowns have to be quickly taken care of in order to ensure the boats’ reliable operation, especially during the peak season when thousands of passengers want to cross the lake every day. That’s why a replica of the old motors is an optimal solution for the customer as well as a sensible investment.

Since preparations must be made before Siemens can submit an offer to Bayerische Seenschifffahrt, Hunsicker quickly gets an overview of the situation and talks with Brandner about the next steps. Because blueprints no longer exist for the motor, one of the old electric drives has to be brought to Hunsicker’s repair center, where the motor can be disassembled. Once new blueprints have been made, the replica motor can be built within eight months so that it can be delivered to the customer on time for the peak season. Before Hunsicker drives back to his office, Brandner invites him to get into one of the boats and travel to the pilgrimage church of St. Bartholomä. This trip is an absolute must, because the captain always blows his highly polished trumpet in the middle of the lake to make the world-famous double echo resound at the steep Brentenwand cliffs. Now Hunsicker knows that there was a very good reason for driving all the way to Königssee: Extremely quiet motors will help to preserve a little piece of paradise.

Kerstin Schreiner, Andreas Binner