VESSEL REVIEW | Zeeleeuw – Hybrid maintenance and geotechnical investigation workboat designed for Dutch inland waters
Van der Straaten Aannemingsmaatschappij has brought the hybrid workboat Zeeleeuw into service for hydraulic engineering, maintenance and geotechnical projects in Dutch waters, following her christening on July 10, 2026.
The vessel measures 30 metres (100 feet) long and eight metres (26 feet) wide and has a draught of only one metre (3.3 feet). Her equipment combines a deck crane, two spud poles and a geotechnical moonpool with battery-supported diesel-electric propulsion.
The shallow draught makes Zeeleeuw suitable for work in inland and tidal waters. Van der Straaten listed a sailing speed of approximately 9.7 knots.
Zeeleeuw has a Stage V-compliant diesel-electric drive incorporating Volvo Penta generators. Electric propulsion is provided by a 400kW Oswald permanent magnet motor with an integrated thrust bearing.
Batteries for extended endurance
The onboard energy storage installation comprises a 430kWh lithium iron phosphate pack with a battery management system. Oechies Elektrotechniek supplied the electric propulsion installation, the battery pack, the power management system, and the electrical installation. De Waal Machinefabriek supplied the propeller shaft installation and steering system as well as the rudders.
Van der Straaten said Zeeleeuw is its first workboat capable of sailing and working completely local emission-free. In addition to the internal battery package as standard, an external battery package can be added for local emission-free sailing over longer distances.
Zeeleeuw carries a Fassi deck crane rated at 80 tonne-metres, with a stated reach of 20 metres (66 feet). Her intended applications include construction and maintenance of quays, shoreline connections and lock complexes, together with emergency work at water engineering structures.
Two 20-metre spud poles hold the vessel in position during work. Van der Straaten said the poles are couplable, while Van Wijk Machinefabriek supplied the spud equipment as well as the anchor.
Fitted out for coastal and inland geotechnical investigation
The integrated moonpool enables the workboat to undertake geotechnical investigations, including probing and seabed or riverbed investigation. Used with the spud poles, it allows Zeeleeuw to serve as a stable investigation platform as part of the contractor’s geotechnical operations.
A fully equipped workshop is installed on deck so that repairs and adjustments can be undertaken even during projects. This facility supports work at the project location, alongside the vessel’s crane and investigation equipment.
Built for operation involving dangerous goods
There are also a removable work pontoon and coupling winches. These extend the operating role to work involving coupled equipment and pontoons, in addition to tasks undertaken directly from the workboat.
Zeeleeuw is certified under the European Standard for Inland Navigation vessels. The vessel is also approved for convoy operations under the European Agreement concerning the International Carriage of Dangerous Goods by Inland Waterways (ADN).
Van der Straaten said that work in petrochemical ports is also covered by the ADN certification.
The vessel’s hull was built in China and then transported to the Netherlands on a heavy lift ship. Final outfitting took place in Werkendam.
Hoogendoorn 1961 undertook the complete interior fitout, including furniture, sanitary fittings and tilework, while Kieboom Werkendam supplied the ship’s equipment, ropes, coupling wires and tender.
Zeeleeuw will be operated in conjunction with Griend, Van der Straaten’s existing multi-purpose workboat. Compared with Griend, Zeeleeuw is longer and wider and has a shallower draught.
