Heerema Marine Contractors has shortened the North Atlantic transit of its semi-submersible crane vessel Sleipnir by 2.5 days using a data-driven voyage optimisation pilot. The pilot was conducted together with French ocean intelligence company Amphitrite.
The optimised crossing reduced the sailing distance by 240 nautical miles and cut CO2 emissions by up to eigtheen per cent, while maintaining higher average speeds without increasing fuel consumption.
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Operational data and weather intelligence
The pilot combined Heerema‘s offshore expertise with Amphitrite‘s vessel-specific voyage optimisation platform, using five years of operational data supplied by Heerema to develop a model that predicts Sleipnir’s speed and power consumption under changing weather, wave and ocean current conditions. Unlike generic weather routing, Amphitrite’s approach combines vessel-specific performance modelling with high-resolution ocean current, wave and weather intelligence.
Sleipnir, the world’s largest semi-submersible crane vessel, was mobilising from Rotterdam to New York to install an offshore wind substation. North Atlantic winter conditions put the vessel to the test, with rapidly changing winds, waves and ocean currents providing a demanding proving ground for the routing model.
Shortly after departure, the system identified the optimal sailing window to benefit from tidal currents in the English Channel. As the crossing progressed, it recommended a more northerly route around a developing storm, allowing Sleipnir to make use of favourable tailwinds while remaining close to the great-circle route.
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Longer route, shorter transit
The return crossing demonstrated another advantage of dynamic voyage optimisation. Rather than following the shortest route, the model directed Sleipnir towards the Gulf Stream. Although the vessel covered a greater distance, favourable currents increased its speed over ground to 14.6 knots, reducing the overall transit time despite the longer route.
The collaboration forms part of Heerema’s wider use of Amphitrite’s Ocean Bulletin, supporting crews and operational teams with ocean intelligence for voyage planning and offshore project preparation across its fleet.
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Decarbonisation strategy
The pilot project also provided Heerema with valuable insights into the transit performance of Sleipnir, creating new opportunities to further reduce fuel consumption during one of the vessel’s most energy-intensive operating phases. The company says improving fleet efficiency is a key part of its decarbonisation strategy.
According to Amphitrite, the trial showed that combining vessel-specific performance models with high-resolution weather and ocean data enables more efficient voyage planning. The result is shorter transit times, lower fuel consumption and emissions, and more efficient mobilisation of offshore vessels.
Picture: Heerema’s Sleipnir in transit (photo by Heerema Marine Contractors).
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