200 Years of the Weilbach Foundry: Keeping Trucks Balanced

What is the key component of a modern forklift truck? This is up for debate: It could be the hydraulics or perhaps the engine. In electric forklift trucks, it could even be the battery or, more recently, you could say digital networking. But there’s no lack of certainty when it comes to the largest and heaviest component: It’s the counterweight, without a shadow of a doubt. It keeps the forklift truck and its extremely heavy load balanced, almost like a seesaw. The truck is prevented from tipping over because, if you include the counterweight, it makes it heavier than the (maximum permissible) load on the prongs.

Where is this extremely heavy component manufactured? For the KION Group, two sites in Germany are tasked with this job. The Dinklage site in Lower Saxony has around 150 employees who produce 60 counterweights every day which weigh up to six tons, predominantly for the brand STILL. This has been the case since 1974. But Linde Material Handling’s ‘Plant 4’ in Weilbach, Odenwald, has a much longer history: The KION brand’s plant is celebrating its 200-year anniversary this year. There is a distinct smell of sulfur and paint here, as sparks fly in the cupola furnaces at temperatures exceeding 1,500 degrees Celsius —that’s pure industrial romance, right there. Both the KION Group’s foundries also simultaneously work with state-of-the-art production methods.

For example: Once the counterweights are removed from the mold after casting, the cast blocks have to be ground and freed from what is known as “flash.” This tedious process used to be completed by hand using an angle grinder, but is now performed by “cleaning robots” at the plant in Weilbach.

A total of 12 million euros has been invested in the Weilbach foundry in recent years. “The component is becoming increasingly complex,” says Frank Koch, who has overseen the plant since 2018. This is because the counterweight also protects the truck’s engine which requires tailor-made cavities so that it can be used without any problems. These are created with the help of sand cores, in a production process known as ‘shot blasting’. Sand and binding agents are mixed in the core shooting machine and shot into a mold at high pressure. The finished cores are immersed in a heat-resistant liquid and inserted into the mold. Incidentally, this is also how the openings for trailer couplings are created.

Such levels of precision were still inconceivable in 1822 when the then 29-year-old Johann Michael Reubold founded the plant—initially known as “Eisenhammer”. A craft enterprise for the production of wrought iron. Just four years later, Reubold expanded his business, received the smelting concession, and subsequently started to manufacture cast-iron furnaces, gear wheels, and mill engines. In 1899 two businessmen from Frankfurt took over operations and the plant specialized in the production of heating and drying equipment, rotary furnaces, and apparatus for the chemical industry. Components weighing up to 3.5 tons were already being casted in Weilbach, even then.

After World War Two another specialization followed, this time in the individual parts of engines and impellers for turbines. It is even alleged that turbine parts for the Aswan High Dam were produced in Weilbach during the 1960s. Since May 1975, the foundry has belonged to the KION brand Linde Material Handling. Playing a key role in the acquisition at the time was the foundry’s geographical proximity to Linde’s forklift truck assembly plant in Aschaffenburg—the distance between the two sites is only around 35 kilometers. Now 165 counterweights for forklift trucks leave the Weilbach farm every day: Perfectly cast, ground, and painted red—the traditional color of Linde trucks—in most cases.

“I’m incredibly proud to be part of this history and delighted that we have permission to shape the future of the plant,” says Plant Manager Frank Koch about the site’s anniversary. The most important challenge for the coming years is the issue of sustainability, Koch continues: “We want to drastically cut down on our carbon emissions.” Counterweights consist of 100% melted scrap metal such as from discarded manhole covers or old water pipes. “If you think about it, foundries have always recycled,” says Koch with a smile. But cupola furnaces like the one in the Weilbach foundry consume a lot of energy.

How can the site’s high energy consumption on the one hand be reconciled with its stated ambition for sustainability on the other? Weilbach has set up a task force to tackle this very issue, dealing with a range of approaches along the way. One of these is a test with organic coke, with preparations currently underway. Plant Manager Frank Koch elaborates: “Coke is the current energy source, enabling us to process more than 50,000 tons of metal. Conventional coke is produced from hard coal and is therefore a fossil fuel. By contrast, organic coke is made from biodegradable waste products.” These are generated in agriculture and forestry, for example, as well as in the wood, recycling, and food industries.

Koch is still unsure how the switch to organic coke will impact the Linde’s ecological footprint: “Firstly, it’s about collecting the relevant data,” says the plant manager. “Up to now, there haven’t been any foundries with organic coke in series production. Therefore, it’s only through our own experiments that we can see how the initiative affects our carbon footprint.” But as it stands, one thing is for certain: The Weilbach foundry is thinking ahead—even after 200 years.