At the peak of possibilities

The trolley is snowed in. In mid-September. High up on the Zugspitze, Germany’s highest mountain, this is not a rare event. Luis Schwatz dons his helmet, puts on his climbing harness and climbs the frosty ladder with a colleague until he reaches the boom, then continues for three or four more metres. It’s a first-class vantage point. He’s a dizzying 2,500 metres above sea level, with the shining turquoise Lake Eibsee lying at 973 metres above sea level. The Zugspitze is cloaked in cloud. The views are breathtaking, but it’s a vacuum, so he can devote his undivided attention to the trolley of the Liebherr tower crane. If it starts up with its weight on the hook - a prefabricated concrete part - chunks of snow and ice could fall onto the site below. To prevent this, Luis Schwatz is armed with a scraper and a few blows of a hammer. Now the trolley can work safely and freely.

The crane is perfect for us up here. Its handling is straightforward and it’s the ideal support for construction companies on mountains.

Luis Schwatz

Not for the faint-hearted

Luis Schwatz is a crane operator on Germany’s highest construction site. Those up here working on the new Eibsee cable car need to be weather-resistant, have a head for heights and not squeamish under any circumstances. It’s the only way to keep the machinery and materials in good condition at almost 3,000 metres above sea level. When Schwatz isn’t clambering around on the 50-metre-long boom, he is operating the Liebherr 150 EC-B 6 Litronic flat-top crane via wearable remote control. “The crane transports materials to the different areas of the site or removes construction waste. This is best done from the site below, where we have a better overview of the different site areas than we would from the cockpit”, says Schwatz. And then there are the visitors that flock to Germany’s top tourist attraction every day, who can also watch the ongoing site work. “We have been working up here for three years”, says Schwatz. “Always with an audience”, he adds with a smile. “Our site has almost become as big an attraction as the mountain itself”. And with good reason. Up on the Zugspitze, technological history is being made.

Really strong: With extreme conditions athigh-altitude, the crane, with parts weighing many tonnes, is assembled by helicopter with millimetre precision.

Building a cable car: it’s an adventure

The old Eibsee cable car was decommissioned in April, making way for the new system. The good old rack railway is currently the only way to climb from the valley station towards the summit of the Zugspitzgipfel, taking around 45 minutes. On board is Martin Hurm. He is the manager of the cable cars and lifts on the Zugspitze and is responsible for the construction of the €50 million new cable car construction project in his capacity as project manager for the Bavarian Zugspitze Railway (Bayerischen Zugspitzbahn). Everything is coming together for the Deggendorf native. “If I had foreseen how much work it entails...”, he says, laughing.

The 49-year-old clearly delights in being part of making technological history in this unique location. And he’s in good company. The tourist development, new construction and extensions have been long-running projects for train operators on the Zugspitze since the early 1930s. The Eibsee cable car was built in 1963 to extend and alleviate the rack railway. It was a success at the time. Perhaps too much of a success, as it reached the limit of its capacity in the late 1960s when the great ski boom was gathering momentum.

A high-altitude construction site is an adventure in many ways. Technological, engineering, logistics, height and weather conditions.

Martin Hurm

Many virtues required

Ever since, maintenance and modernisation have been long-term plans on the Zugspitze. The thing is, they’re not all that easy to implement up on the mountain. “An alpine construction site is an adventure in many respects”, says Hurm. “Technologically, on an engineering level, logistically, and when it comes to heights and weather conditions. And, last but not least, it’s a constant challenge in terms of patience and persistence”.

The ‘reward’ for Hurm and his team is not only the most spectacular view of the site, but also the end result: a superlative cable car, the like of which has never been seen and which is set to break three world records: the highest steel cable car prop (127 m), the largest total elevation gain (1,945 m between the valley and upper stations), and the longest free span (3,213 m). Its previous capacity of 260 will be increased to 580 mountain enthusiasts per hour.

On the top: At an altitude of almost 3,000 meters, the Liebherr flat-top crane becomes an attraction - not only for construction workers but also for tourists on the peak of the Zugspitze.

“No room for planning mistakes”

On a construction site at almost 3,000 metres above sea level, everything has to be perfect. This is ensured by the experts at Liebherr Tower Crane Solutions - a department specialising in planning and implementing very specific applications. Here, project manager Michael Weißschädel tells us how Liebherr’s crane technology is being used at the Zugspitze’s summit.

Mr Weißschädel, challenging construction sites are nothing new for Liebherr’s tower crane solutions. What makes a building site on Germany’s highest peak so unique and challenging?

Michael Weißschädel: The mountain location, the strong winds, the temperatures and the snow and ice make it different to a ‘normal’ site. Every detail must be thought through to be able to safely assemble this special crane on the Zugspitze, operate it safely and dismantle it safely, too. And the view from the highest point in Germany is something truly special for the fitters, service technicians and crane operators.

Which mountain ‘configurations’ were required for the crane?

Liebherr cranes are generally operational at temperatures down to -25°C. The 150 EC-B 6 Litronic also has a particularly strong tower combination, which can even withstand extreme wind speeds of up to 280 km/h.

Which skills do Liebherr team members bring to assembling and maintaining the crane up there?

Our trained fitters and service technicians are no strangers to working at heights - otherwise, they would be in the wrong job. The crane itself is not built at a particularly great height, but there is a drop of a few hundred metres right next to it. It’s impressive, but it’s ultimately not that different to working with a suitable crane on a high-rise building.

What has particularly interested you about this project?

The new Zugspitze cable car is a unique site in a unique location. From a technical perspective, the planning and assembly via helicopter at nearly 3,000 metres above sea level expertly done by all involved. As a result, every little detail had to be considered beforehand. Once the parts are up on the mountain or being lifted by the helicopter, everything has to be perfect - there’s no room for mistakes. The team did a perfect job.

Sky high: the Liebherr flat-top crane 150 EC-B 6 on the Zugspitze

- Erected at 2,950 metres above sea level

- With its boom, it overhangs the 2,962-metre-high summit cross by 13 metres

- This makes the crane the highest point in Germany for the construction period and a few months afterwards

- The jib radius is 50 metres at a hook height of 18.6 metres

- Its modular design means that it can be easily dismantled into individual parts with a maximum weight of 3.4 tonnes

- The crane modules correspond to the maximum load capacity of the helicopter required to transport them from Sonnalpin to be assembled at the summit

The new Zugspitze cable car – taking record-breaking to new heights

From the highest steel pylon to the longest unsupported span to the highest crane in Germany, here’s everything you need to know about the 10-minute journey:

Type: Cable car

Build time: Autumn 2014 – December 2017

Length: 4,466.90 metres

Elevation gain: 1,945.25 metres

Longest unsupported span: 3,213 metres

Zugspitze upper station (platform height): 2,943.75 metres above sea level

Eibsee valley station (platform height): 998.50 metres above sea level

Speed: 10.60 metres/second on the track (8.50 metres/second when travelling over a pylon)

Cabin capacity: 120 people + 1 attendant

Transportation capacity/hour: 580 people/hour

Suspension cable: 4 x 72 mm │Weight: 153 tonnes per suspension cable

Traction cable: 1 haul rope loop: upper traction cable: 47 mm and 39 tonnes

Lower traction cable: 41 mm and 30 tonnes

Number of pylons: 1 steel pylon (127 metres high – as a comparison, Munich cathedral’s two towers are around 100 metres high)

Weight of the steel pylon: 420 tonnes

Drive: At the valley station │ Two drive motors, each with 900 kW nominal power (=1,223.66 horsepower)

Eating and drinking are a little different up here at high altitude

With increasing altitudes, the air pressure reduces and so does the amount of oxygen per cubic metre of air. At 3,000 metres above sea level, the oxygen level is 0.68 mg/l (compared to 1 mg/l at sea level). Working at altitude like on the Zugspitze means that less oxygen enters the lungs and be used by the body, so the oxygen levels in your blood drop. As a result, the body tries to compensate by increasing your heart rate and making breaths deeper. “Drinking a lot when you’re working is recommended: at least three litres of liquid a day”, explains Steffen Korff, chef on the Zugspitze.

The (cappuccino) cup runneth over

The low air pressure changes things: water boils at 86°C at the summit of the Zugspitze. “Pasta takes longer to cook, salad starts to wilt after 20 minutes and soup tastes different when it’s cooked up here compared to down in the valley. You can’t totally rely on recipes up here – cooking at altitude requires a lot of experience and constant trial and error”, adds Korff. The reason for this has been researched by experts at the Fraunhofer Institute for Building Physics in conjunction with Lufthansa. Their sensory analyses in a low-pressure tube concluded that eating and drinking at altitude tastes similar to when we have a cold. Tastes and acidity remain, while salt and sugar are perceived less intensely. Even the coffee machine feels the effects of altitude. Steffen Korff explains: “The thin air at altitude doesn’t agree with the standard settings on the cappuccino machine. The cups were overflowing to start with. We had to adjust the screws until the milk foam had the right consistency”.

Getting tipsy at double speed

“Alcohol feels different”, explains Korff. “A beer or prosecco consumed quickly up here will pick up speed on the rapid journey back down to the valley. The increase in oxygen intake means that the alcohol enters your bloodstream more quickly, so you will suddenly feel tipsier than you thought”.

The project at a glance

A herculean task, right to the end

Since the foundation stone was laid in April 2016, overall project manager Johannes Kaltner has been continuously based at the Gaildorf site with around 35 specialist workers. He says it is the enthusiasm for innovations and what is technically feasible that constantly drives his team on to develop new ideas. "The fact that this construction site is opening a new chapter in Germany's energy transition means that it is not run-of-the-mill work, even for experienced wind-power professionals," stresses Kaltner.

One of these wind-power professionals is Ralf Karras. The Berliner is a crane driver out of sheer passion. Using the joystick, he operates his powerful LTM 11200-9.1 crane, which he has reverentially given the name "Hercules". And with good reason. The 9-axle mobile crane from Liebherr has a 100-metre telescopic boom, one of the longest in the world, and delivers a maximum load capacity of 1,200 tons.

Pretty extreme - working on the mountain

  • Ice cold professionals
    In order to get going in the morning, the workers have to free the steel cable winches of the cable car time and time again from the ice, using gas burners.

    Ice cold professionals

    In order to get going in the morning, the workers have to free the steel cable winches of the cable car time and time again from the ice, using gas burners.

  • Onto a first name basis with frost
    Sub-zero temperatures transform the construction site day after day into a strange ice palace. Whoever works here should not be lost.

    Onto a first name basis with frost

    Sub-zero temperatures transform the construction site day after day into a strange ice palace. Whoever works here should not be lost.

  • Always on the safe side
    Crane operator Thomas Winkler sets the tower crane in motion with the remote control, so he keeps the best overview of all site areas. After all, safety always comes first.

    Always on the safe side

    Crane operator Thomas Winkler sets the tower crane in motion with the remote control, so he keeps the best overview of all site areas. After all, safety always comes first.

  • A hands-on job
    Crane operator Thomas Winkler is multitasking like everyone up here. Shovelling snow is always high on the agenda at a high-alpine construction site.

    A hands-on job

    Crane operator Thomas Winkler is multitasking like everyone up here. Shovelling snow is always high on the agenda at a high-alpine construction site.

  • The impact of the weather
    Martin Humm, Project Manager of the cable car Zugspitze, is the chief of the construction site on the Zugspitze.

    The impact of the weather

    Martin Humm, Project Manager of the cable car Zugspitze, is the chief of the construction site on the Zugspitze.

  • Everything is extreme - even the manager’s composure

    Around 100 people are currently working on the site. The wind is whistling around up at the summit cross. Ice crystals dance around the steel frame and cables. The -2°C on the thermometer feels much colder. Everything up here, it seems, is extreme. Even the composure of Martin Hurm: “You can’t fight the weather up here”, he explains. “But you can make the best of it”.

    The two cable car cabins with floor-to-ceiling glass have already arrived, says Hurm. They’re wrapped up at the valley station waiting to be assembled. “They will be put into operation on 21st December”. There’s no doubt in his mind. And the crane? “It will be staying put until the spring, when all of the work is completed”, explains Hurm. Its concrete foundation will be staying, however. “We know we might need the crane again at a later date”.

    Crane months XXL
    Crane months XXL

    The installation of a crane on Germany's highest mountain requires precise operational planning and support from the air. Click here for the full video of the spectacular helicopter assembly.

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