Alewijnse TSHD Swalinge 6 1 800X280 (1)

Alewijnse celebrates successful electrical delivery of unique trailing suction hopper dredger Swalinge

December 22 2022

Systems integrator Alewijnse has successfully completed the electrical refit of the trailing suction hopper dredger Swalinge for Den Herder Seaworks' fleet at shipyard Kooiman Hoebee in Dordrecht. To expand the vessel's cargo space from 1800m³ to 3000m³ the vessel was cut in half and a new, 37.1-meter section inserted. In addition to the lengthening, the Swalinge has been substantially modified in other areas to further maximize its versatility. For example, the vessel has been equipped with two spud poles, a second bow thruster, a new propellor nozzle around the thruster, another bulb stern and a new, unique, hydraulically adjustable separator for the dredging system, an application that few dredgers today have. Alewijnse, a global organisation with more than a century of experience in marine electrical engineering, was responsible for the complete electrical installation on board. Electrical production supervisor Kees de Waardt says: "It was an extensive project, in which we modified and expanded the electrical systems almost everywhere on board. “Our main activities included extending the cables in the ship's hopper corridors; upgrading the main switchboard to accommodate the integration of the new bow thruster and hydraulic pumps; the wiring and connecting of the complete dredging installation including the hydraulics system, jet water system, suction pipe gantries and drain system. We also modified several subsystems such as the wheelhouse desk, the alarm and CCTV systems and all the lighting on board."

Successful cooperation

With the delivery of the Swalinge, Alewijnse and Den Herder Seaworks confirm their many years of successful cooperation in the field of electrical installations and automation. Previous projects that Alewijnse has successfully completed for Den Herder Seaworks include the electrical fitout of two sisterships of the Swalinge; the newbuild TSHD Scelveringhe and the TSHD Spauwer. In addition, Alewijnse has been providing service and maintenance services to the Den Herder Seaworks fleet for many years. Alewijnse Project manager Mitch Opmeer adds: "We have built a good relationship with each other over the years, and Den Herder has gained confidence in the skills that Alewijnse has to offer. Our highly motivated and skilled workforce was the key to delivering this large and unique project successfully and on time for the owner.” Pieter den Herder of Den Herder Seaworks confirms the excellent cooperation: "Alewijnse is a reliable and professional partner for us. Our projects are delivering good results and we are very satisfied with Alewijnse’s extensive knowledge and expertise, flexibility and service, and the quality of the vessels that it delivers.”


The Swalinge was built as a coaster in 1977 and converted into a trailing suction hopper dredger after being purchased by Den Herder Seaworks in 1996. The dry unloading installation was designed and built to Alewijnse’s own specifications and delivers an average unloading time of 2.5 to 3 hours following the recent conversion. The hopper is fitted with bottom doors so she can rapidly dump her sediment and she is also capable of using shore delivery installations for pumping it ashore. The key to the company’s success is its highly skilled crew and the high standard of maintenance which ensures the reliability of Den Herder Seaworks’ fleet.