"Specializations and emission-free innovations in concrete and hydraulic engineering? We're going for it!"

De Vries Werkendam BV has been a specialist within all disciplines of concrete and hydraulic engineering since the 1960s. They realize projects for new construction, maintenance, renovation and restoration of all common hydraulic and civil engineering structures and objects. We talk to Dammes Oldenburg (director of de Vries Werkendam) and Hendrik van de Woestijne (manager of sister company De Vries Titan) about their specializations and the latest innovations.

Three companies

The three companies consist of the specialists De Vries Titan and De Vries VSP, also known as Tensa, in addition to hydraulic contractor De Vries Werkendam. "With this we put a strong stake in our various specializations," explains van de Woestijne. "The operating companies have a strong synergy with each other. So we work independently, but also in cooperation with each other. We can exchange personnel and equipment, for example. In this way, we offer continuity for our customers and catch the vacancies on projects by helping each other."

De Vries Titan is a specialist in foundation and anchoring techniques. "We are always involved from the beginning of a project to place the foundations. This can include anchors, anchor piles and laying anchors. We participate in several large projects in the Netherlands, Belgium and Germany. Think of large infrastructure projects such as the Afsluitdijk or the Blankenburg connection. We install the anchors and when they are up to strength, we also test and tension them immediately. Because of course you want the anchor to be well anchored in the ground and at the right tension so that the construction is secure," says van de Woestijne. 

De Vries Werkendam is also making considerable headway with its sister company Tensa. "Tensa focuses on prestressing concrete decks. The company supplies anchoring and pre-tensioning systems, assembles the complete system and pre-tension the deck after the concrete has been poured. By prestressing such a concrete deck, it can be made lighter. This saves considerably on materials, which improves sustainability."

Tensa and De Vries Titan often work together. In fact, for tensioning and testing anchors and pre-tensioning concrete decks, the companies use the same kind of techniques. "In this cooperation, we really see a future," says Tensa.

Working vessel the Ruigt

"Our government is maximally stimulating the transition to electrically powered equipment. Although this is a multi-year program, there are already plenty of EMVI projects being issued today in which the highest EMVI score can be achieved with emission-free realization of projects. So if we as companies want to stay in the game, we have to invest in new emission-free equipment. We are busy building a completely emission-free work vessel De Ruigt. The 50 by 9.5 meter ship is now in the finishing phase and will be ready to go to work in December 2022. The ship's propulsion is electric. Both the main thruster (500 kW) and the bow thruster (150 kW) are electrically driven. The winches of the spud poles, deck wash, spray pump (33 kW) and the entire onboard network (including all-electric welding, etc.) are also electrically driven. The vessel will have a battery pack from which all power consumers will be powered. The required power will be supplied by two Volvo hybrid hydrogen generators with a capacity of 351 kVa each. The switch to hydrogen as a fuel will take place during 2023. This will make our new flagship a 100% zero-emission ship. This will give us a multi-purpose ship with zero emissions. And that's nice: because one of our specializations is inner-city reconstruction. It is then a great advantage that we can work emission-free and electric, for residents, our customers and our climate! In the near future we are going to repower our other pile driving vessels with engines that meet the highest emission standards and invest maximally in a sustainable future for the De Vries Group."