On 29 November 2025, the 4,500 t topside of the offshore substation OSS Jasmund was moved through central Rotterdam on the barge H-408, attracting attention along the river route. The structure had been assembled at HSM Offshore Energy BV’s Stormpolder yard in Krimpen aan den IJssel before departure.
The platform is being delivered to German grid operator 50Hertz Transmission GmbH by a consortium that includes HSM Offshore Energy BV, Smulders, Iv-Offshore & Energy and InterDam. Designed to handle 300 MW of offshore wind capacity, the topside will supply electricity to more than 260,000 households once installed in the German sector of the Baltic Sea as part of the Windanker offshore wind farm.
See also: OSS Jasmund Set for Transportation
From Krimpen, the convoy travelled via Koningshaven and under the Koninginnebrug, continuing via the Nieuwe Maas towards Rotterdam’s Waalhaven. Clearance at the Koninginnebrug required a waiting period, leaving the large substation platform temporarily positioned amid the city’s buildings and bridges.
Marine transport for the move was arranged using the H-408 barge operated by Heerema Marine Contractors, following load-out operations carried out by Mammoet at the Stormpolder facility. Industry association NedZero – Wind Energy Association highlighted the project as an example of Dutch fabrication, shipping, engineering and offshore expertise coming together for a single heavy-lift transport.
