Dirk the Great

Transformers in Amprion’s power grid provide millions of people with a secure and reliable supply of electricity. If these machines – which weigh more than just a few tonnes – need to be replaced, the new unit travels to the installation site by rail. This is why Amprion has had the largest rail vehicle in Germany built. The story of a giant.

Its nickname is Dirk – and there’s no missing it. Not just because of its sheer size. This matt grey leviathan is 52 metres long, weighs 220,000 kilos and pulls 500-tonne loads. Thanks to its curved, beak-shaped steel arms, it’s also known in German as a “Tragschnabelwagen” (Schnabel = bird’s beak), or “Schnabel car” in English. It’s also known as the TSW 500, for short. Dirk is the latest member of the family of heavy-duty railcars Amprion uses to transport huge transformers. Among trainspotters, Dirk the Great is already quite a sensation. “That’s because it’s the heaviest rail vehicle in Germany,” says Felix Mangold.

“It’s the heaviest
rail vehicle in Germany.”

Felix Mangold

Mechanical engineer at Kübler

The qualified mechatronics and mechanical engineer knows Dirk better than almost anyone else. He works for the Swabian company Kübler, which built the TSW 500 for Amprion. Mangold spent several years working on the car. He planned, calculated and kept checking the calendar to make sure Dirk would be completed on time. September 2020 saw it all come together – and Dirk was handed over to Amprion. At the brief ceremony held at Kübler’s heavy-cargo terminal at the Port of Mannheim, the 31-year-old had mixed feelings. “It hurts a little to let go,” Mangold admits. But it’s also great to see the car actually go into service.

Critical look: Felix Mangold makes sure the car functions properly. The height of the load can be raised and lowered remotely.

Long search for a manufacturer

Amprion has big plans for Dirk: over the coming 40 years – that’s how long the TSW 500 is intended to be in service – more than 500 transformer transport assignments are scheduled. Transformers are located in substations, where they help to secure the power supply for millions of people. Amprion regularly replaces them or brings new machines to their installation site. “Every year we add a few transformers to our grid,” explains Henrik Kastner, rail operations manager at Amprion. As part of the energy transition, Amprion is expanding its grid in order to transmit more wind power from the north to the consumption centres in the south of Germany. This also includes upgrading the substations in the grid with more powerful transformers.

But heavy-duty Schnabel cars for transporting these machines are hard to come by. “We searched for a long time for a company that makes them,” Kastner says. To no avail. Kübler had previously had the same problem. The heavy-cargo specialist had themselves needed new Schnabel cars, but were also unable to find a supplier. For this reason, in 2015 the forwarding company decided to design their own Schnabel car, to have the parts made to order and to assemble them themselves. “Kübler was the ideal partner for us,” says Kastner and also explains where the nickname Dirk comes from: an Amprion executive whose first name is Dirk had championed the purchase. His grateful colleagues consequently named the new vehicle after him.

Family get-together: on the day of the handover, a smaller Schnabel car, which Kübler uses to transport large and heavy materials, was parked on the track to the right of Dirk.

Schnabel cars are extraordinary vehicles. They split into two halves when in use. The transformer is then suspended in the space in-between. Thanks to the cars’ smart design, the forces are transferred and distributed in such a way that the vehicles can transport the heaviest loads imaginable. As the train is allowed to travel no faster than 40 miles per hour, journeys sometimes take weeks. That’s why an accommodation carriage is hooked up behind the diesel locomotive, in which the crew cooks and sleeps. The work is exhausting. During the journey, the massive load has to be adjusted again and again with the help of hydraulics to prevent it from hitting obstacles.

In their previous Schnabel cars, the men from Amprion had to stand outside to do this. “The new Schnabel car has two heated cabins,” says Felix Mangold. And the technical features are also more convenient and modern now. During the handover, the mechanical engineer patiently explains the digital control system and demonstrates the joysticks and coloured buttons on the control panel. He then deftly shimmies along the massive steel girders, explaining the purpose of the many cables and pipes that run through the TSW 500.

Keeping track

In mid-2019, Amprion places the order to build Dirk – and Felix Mangold goes to work. A stressful time? The mechanical engineer smiles and ponders briefly. “We had already acquired a lot of knowledge.” Mangold is a technology fan and likes to talk about it. Even before the order from Amprion, he had had one Schnabel car overhauled and a new one built for Kübler. That’s why he knows where to find suitable design offices, which steel companies come into question, and who he can trust to manufacture bogies, brakes or hydraulic cylinders.

Dirk’s development is a complex project. Almost 200 employees from around 25 suppliers are involved. “The most important task is to keep track of everything,” says project manager Mangold. Especially as the schedule is tight. For legal reasons, Dirk’s construction period must not exceed twelve months.

The finished components are first sent to Kübler’s headquarters in Schwäbisch Hall (south-western Germany). There they are checked and, if necessary, reworked once again. In April 2020, they travel on ten flat-bed trucks to Halle, where the Schnabel car is assembled over two days with the help of a heavy-duty crane. This phase, known as the “marriage”, is a crucial time. Only then do we discover whether the work carried out has been accurate and all the parts fit together.

Long and strong: Dirk already bears the company logo (top). “He” had previously been assembled in Halle with the aid of a heavy-duty crane.

Long and strong: Dirk already bears the company logo (top). “He” had previously been assembled in Halle with the aid of a heavy-duty crane.


companies worked on constructing Dirk.

Flurry of activity before the marriage

As with all marriages, a flurry of activity breaks out just before the scheduled date: the electricians commissioned from an Austrian company are not allowed to travel to Germany because of the pandemic. Colleagues from Kübler have to take over the work. But unfortunately, the hotels in Halle are closed. Mangold finds a solution: “We rented a big house and lived there, observing the social-distancing rules.” On the evening of the second day, everyone involved was able to relax again. Everything fits, the fitters tell us. Marriage successfully consummated!

After being assembled, Dirk – who is now capable of rolling – still has to pass one more test: the approval test on a railway test track. There are only two of these in Europe, and the one chosen is located about 60 kilometres east of the Czech capital, Prague. “Experts there put a vehicle through its paces over several days,” Mangold explains. To test whether the brakes also work in an emergency, the car is uncoupled from the locomotive while travelling at full speed. Dirk masters the challenge. The safety systems function and the brakes work without fault.

Vehicle completed and ready to go, mood good: Kübler boss Heinz Rößler talking to Ludger Meier, Head of Grid Projects at Amprion.

Vehicle completed and ready to go, mood good: Kübler boss Heinz Rößler talking to Ludger Meier, Head of Grid Projects at Amprion.

After coming through the tests with flying colours, Dirk is ready to get down to business. Before handover, there’s one finishing touch: the Amprion logo and stripes in the company colours are applied. After all, Dirk the Great should always cut a good figure on his journeys around Germany.

TextHeimo Fischer
PhotosRaphael Foidl