The passage took place on Tuesday shortly before 1 pm, as reported by the Danish trade publication Maritime Danmark. The vessel’s unusual size meant that passing under the bridge required a carefully planned manoeuvre. The day before, two pilots had boarded the vessel near Skagen to discuss the route and the passage with the ship’s command.
Deeper into the water for the bridge
The Great Belt Bridge offers ships a nominal clearance of 65 metres. According to Maritime Danmark, the ‘Pioneering Spirit’ protrudes too high above the water when lightly ballasted. To pass under the bridge, it took on ballast water, thereby increasing its draught from 11 to 19.9 metres. The problem is this: whilst the depth directly beneath the bridge is around 60 metres, the ‘Tango’ deep-water channel itself has a minimum depth of only 19 metres. According to DanPilot After passing through the channel, the ship pumped out ballast water for around four hours before continuing through the narrows to the south.
The twin-hull vessel operated by Allseas is regarded as the world’s largest workboat. Its twin hulls are capable of accommodating an offshore platform between them.
| Parameter | Pioneering Spirit |
| Fuselage length and width | 382 m × 124 m |
| Opening between the bow sections | 122 m long, 59 m wide |
| Draught | 11.5 m for overpasses; up to 27 m when in operation |
| Height above water | 57 m with a draught of 26 m |
| Installed capacity | 95,000 kW (95 MW) |
| Drives | 12 rotatable propeller nacelles, each with a power output of 6,050 kW |
| Maximum speed | 14 knots |
| Accommodation | for 571 people |
| Load capacity of the specialised lifting systems | 60,000 tonnes for platform superstructures; 20,000 tonnes for substructures |
| Heavy-duty crane | 5,000 tonnes at a 35-metre reach |
The Guinness World Records The “Pioneering Spirit”, with a gross tonnage of 403,342, is the largest ship by gross tonnage and also the largest workboat. It is not the largest crane vessel; that title is claimed by “Sleipnir”. It has two cranes, each with a rated load capacity of 10,000 tonnes. The ‘Pioneering Spirit’ specialises in lifting entire platform sections.
Two platforms for the gennaker
Off the coast of Darß, the ‘Pioneering Spirit’ is set to transport and install the two offshore substation platforms, OSS Darß and OSS Zingst, together with their substructures. This is according to the Project description by Allseas stand out. The substations later collect the electricity generated by the wind turbines and transmit it towards the coast via the OST-6-1 grid connection. 50Hertz estimates their transmission capacity at up to 927 megawatts. The construction site is situated around 15 kilometres north of Fischland-Darß-Zingst, and full operation is scheduled for the end of 2028.
What skippers should bear in mind off the Darß peninsula
For motorboat users, it is not so much the size of the workboat that matters as the stage of construction in the area. A Notice from the Baltic Sea Waterways and Shipping Authority announced that safety zones with a radius of 500 metres each would be established around the substation platforms, into which vessels are not permitted to enter. BOOTE explains the general rules that apply when sailing near such installations in the An overview of offshore wind farms.
Hauke Schmidt
Test & Technology editor
