Lake Zürich is known as a place of recreation for large numbers of Swiss people, as a popular tourist destination, and as a drinking water reservoir for the entire region – but in fact it is also a major traffic route. Ferry company Zürichsee-Fähre Horgen-Meilen AG operates five car ferries on the lake, taking cars, trucks and cyclists between the western and eastern shores of the lake in 10 minutes and saving them a 35-kilometer road trip. It does this 16 hours a day, 365 days a year. The ferries are powered by reliable, tried-and-trusted Series 2000 MTU engines that run tirelessly – up to three times longer than the actual operational lifetime recommended by MTU.
It's a sunny day in June with a blue-and-white sky and temperatures a balmy 28°C, with the Swiss Alps visible to the south and the vibrant city of Zürich to the north. On the clear, blue-green waters of Lake Zürich, the ferries Horgen and Burg meet each other and pass by – an idyllic picture-postcard scene, but also a very everyday occurrence on Lake Zürich, Switzerland.
It all starts at 6 o'clock in the morning, when the first ferry, MV Zürisee, casts off from the community of Horgen on the eastern shore of the lake en route to Meilen on the western shore. By the time the rush-hour gets underway at 6:30 a.m., the other four ferries are also in operation: the MVs Horgen, Burg, Meilen and Schwan, departing at 6-minute intervals to take commuters, schoolchildren, cyclists and trucks to the other side. At around 8:30 a.m., the first flurry of the day subsides, and over the next few hours the lake is crossed by just three vessels, departing at 10-minute intervals. However many ferries are in operation, though, one thing never changes: the routine. The engine technician waves cars, cyclists and pedestrians onto the ferry and allocates them spaces. Once the ferry is full, or when all passengers are aboard, he closes the barrier, and the ferry departs. The purser collects the fares during the 10-minute crossing: 9.50 Swiss francs per car, SFR 3 per bicycle and SFR 1.50 per person. Having reached the other side, the engine technician raises the barrier and orchestrates the disembarkation procedure with waves of the hand, mainly in silence and in a manner somewhat reminiscent of a policeman directing traffic. It's immediately obvious that this is a man in complete control of things. Soon the ferry is empty, and the next passengers are coming aboard. Turnaround time is 4 to 5 minutes, and then it's back underway to the other side.
Up to 16 hours without a break
This practiced rhythm works for various reasons, including the fact that each of the five ferries has two 8-cylinder Series 2000 M60 MTU engines aboard, working without interruption. The engines are throttled back during embarkation and disembarkation, pressing the vessels against the dock. Each engine is capable of delivering up to 400 kW of power, running for up to 16 hours per day. Cast off, steam across, dock, repeat as necessary. Three engine speeds are used in this process: 600, 1,200 and 1,800 rpm. Three ferries are always in operation, with the remaining two taking a break between rush hours. Which vessels are in operation, and which are temporarily out of service, depends on the maintenance schedules for the vessels and their engines.
“Last year, we transported over two million passengers and 1.2 million cars,” says CEO Martin Zemp.
The ferries run 365 days per year. An engine technician, a skipper and a purser are always aboard, with extra land-based staff helping marshal cars and trucks during peak hours. Operating company Zürichsee-Fähre Horgen-Meilen AG has a total of 52 employees working shifts all year round. “A company excursion with all our employees is only ever possible when the lake freezes over,” jokes Adrian Meier, the company's Technical Manager. The last ‘big freeze’ was in the winter of 1962/1963. “Other than that, it takes a perfect storm like 'Lothar' in 1999 to force us to interrupt operations,” adds Martin Zemp. 60,000 operating hours per engine 16 hours a day and 365 days a year – the Series 2000 MTU engines are not long racking up the hours: “The engines run about 5,000 hours per year,” confirms Workshop Manager Adrian Hauser. “Our ferries operate for 12 years with their twin engines, making around 60,000 hours per engine – and without any major overhauls either,” he adds proudly. In point of fact, the MTU recommendation to Series 2000 customers is to put their marine engines through a major overhaul after 24,000 hours of operation, which is calculated to be the end of the engines' useful lives. The Swiss customer has managed to achieve two-and-a-half times this, thanks to a well-thought-out, meticulously followed service plan and a healthy dose of selfconfidence.
It all started in 1999 when Zürichsee-Fähre Horgen-Meilen AG was given an 8-cylinder Series 2000 test engine for a two-year trial on the lake. “We maintained the engine exactly as per the service intervals and sent oil samples off to Friedrichshafen,” says Adrian Hauser. At the end of the two years, the engine was stripped down and inspected at the MTU plant in Friedrichshafen. The prototype was found to be in top-notch order. Meanwhile, two new Series 2000s were already in operation aboard the Zürisee. “We kept on sending in oil samples and following the maintenance schedule, and they said we should be able to keep on going. As the years have gone by, we've edged our way forward bit by bit to 60,000 hours of operation in several of the ferries,” explains Adrian Hauser. Continuous operation without stopping and starting the engines, and running continuously at 1800 rpm are also ideal conditions for the engine. Minor routine maintenance tasks such as oil and filter changes are performed by Adrian Hauser and his team when the vessels dock after rush hour, or during winter time when the timetable is a bit more relaxed. For sizeable maintenance tasks, mechanics come from the general agent's office in Schlieren. No one knows the engines and ferries as well as Adrian Hauser, with his 25 years of professional experience at Zürichsee-Fähre Horgen-Meilen AG. “It's almost like they know when he's away – the engines and ferries start playing up,” grins Adrian Meier. Uwe Linz from MTU Marine Engine Sales says, “This number of hours per engine is pretty unusual, and it's also down to good servicing by the customer.”
New ferry also to carry MTU engines
The low cost over the full life of the engine, and positive experience with the engines to date, all helped convince CEO Martin Zemp, Technical Manager Adrian Meier and Workshop Manager Adrian Hauser to buy MTU when new engines were called for: once the decision was taken in 2016 to decommission the Meilen and replace her with a successor, the decision came down once more in favor of MTU. Two 8-cylinder Series 2000 M61 engines – each delivering 400 kW – are now set to power the new Meilen. The new ferry will have a broader beam and a longer length overall, and will be able to take more cars, trucks and passengers. Diesel particulate filters will reduce emissions, making all passages clean and green. By departure from its sister ships, the new ferry also has another new control feature to reduce fuel consumption.
“We can't wait to use this economy mode,” says Adrian Hauser, before Martin Zemp adds, “We're hoping it will save us a lot of fuel.” The special thing about the power train is that MTU has collaborated closely with propeller manufacturer Voith, gearbox producer ZF and Voith Hydro, who has supplied a hydraulic coupling. “We've finetuned the interactions of these components very precisely. The variable engine speed, designed to work perfectly with the Voith-Schneider propeller, is set to propel the ferry more efficiently,” explains Gerhard Götz, who is taking care of the propulsion system for MTU.
The ferry is still at the shipbuilder's in Zürich, having its internal fit-out, but in just a few weeks' time it will be launched on Lake Zürich among the Swiss Alps before taking up its duty in September, ferrying passengers between Horgen and Meilen.
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