In Werkendam, SDK Engineering prepares construction machines for the energy transition

Steven de Kam runs an engineering company from Werkendam that gives construction machines a second life. With hybrid and electric conversions, a new production hall, and magnet-free motors, SDK Engineering is taking the next step.

Anyone who talks to Steven de Kam quickly notices that he is not one to sit still. The director of SDK Engineering combines the down-to-earth attitude of a diesel specialist with the enthusiasm of an engineer who is constantly pushing boundaries. From Werkendam, his company delivers complete drive solutions for heavy machinery, from fully electric to hybrid and everything in between. The recent expansion with a production hall of 1,800 square meters marks a new chapter.

"We already had 940 square meters of workshop, but now we've added a tall warehouse with large doors," says De Kam. "This allows us to carry out complete conversions and new builds of machines. From problem to solution, to execution, to inspection. Literally from A to Z."

Practice over theory

SDK Engineering explicitly positions itself as a system integrator. The company designs, engineers, and builds complete drive systems, both electric and hybrid. What sets the company apart is the breadth of its expertise. Electrical engineering, mechanical engineering, drafting, and software: everything is done in-house. De Kam sees this as the key to workable solutions.

"Our roots are in diesel engines. We really have our feet in the mud," he says. "In the past seven years, we've built up our own knowledge in the field of electric and machine construction. As a result, we can deliver particularly practical solutions that are truly out of the box."

Broad portfolio, always custom-made

The order portfolio of SDK Engineering reads like a catalog of the energy transition in construction. The company builds complete hybrid generator sets from scratch, electrifies machines with battery packs or mains power, develops mobile battery containers on tracks, and provides existing machines with hybrid retrofits. The power range runs from 5 kW to 1,500 kW and from 20 kWh to 2 MWh of storage capacity.

"Every customer has a specific wish," De Kam explains. "One works with the machine in way A, another in way B. You could go for one size fits all, but that's a bit like a Swiss army knife. It has everything on it, but in reality, nothing works 100 percent perfectly. We really focus on customization."

Silent Piler and anchor drilling machine

A striking example is the conversion of a Silent Piler from Giken for contractor Sterk. SDK Engineering replaced the original power unit with an electric-hybrid drive and designed a completely new undercarriage to fit the battery packs. "The batteries didn't fit anywhere," says De Kam. "So we engineered a complete carriage that fits entirely underneath. That is then integrated into one workable machine."

Earlier, the company made an anchor drilling machine from Hakkers hybrid, and SDK Engineering is now working on converting a 35-ton Doosan for sheet piling, fully electric with 833 kWh. A 120-ton Sennebogen crane also received a hybrid installation with a custom-made battery pack. "You name it," says De Kam. "We're now working on the third machine for Hakkers and the third for Sterk. It all comes back."

The operator determines the success

Behind all this technology lies a philosophy centered on the user. De Kam emphasizes that a converted machine must feel familiar to the operator. "Deep down, it may be a kind of space shuttle, but on the outside, it shouldn't be a space shuttle in terms of use. Keep it simple. An operator must be able to work with it blindly."

That's why SDK Engineering involves operators intensively in every project, even after delivery. "We keep the lines with them very short. What are they running into? What do you feel? What do you experience? We also incorporate that feedback into the development of future machines." The best compliment recently came from an operator who, after the delivery of a Woltman 5525DD, gave just one word of feedback: "Monster." De Kam: "That's what gets me out of bed."

Magnet-free motors as the next step

In addition to expanding production capacity, SDK Engineering has entered into a partnership with a manufacturer of so-called reluctance motors. These are electric motors without permanent magnets and without copper, offering the same efficiency as conventional PM motors. The coils are made of pressed aluminum and the rotor of laminated steel.

"It works exactly the same, just without copper and without magnets," explains De Kam. "That has a much lower environmental impact, especially regarding the mining of rare earth metals. And it reduces dependence on countries like China." De Kam expects that this will also play a role in tenders in the future. "The moment you really look at a well-to-wheel picture, this is a significant plus."

Knowledge as capital

Keeping up with the rapid developments in the sector at SDK Engineering happens mainly organically. "I'd almost call it a quirk," laughs De Kam. "We don't do it intentionally. But because of your interest in what you do, you end up reading things at home on the couch." The company also continuously invests in the further development of electronics, data reading, and machine learning software for predictive maintenance.

The message is clear:

"If you think something isn't possible, or have questions about batteries, drive systems, electric, hybrid, combustion engines, whatever. Just get in touch. We'll have a coffee. Because nine times out of ten, the solution is there."