Slow Steaming
Slow Steaming is the practice of operating a ship at a lower speed than its design or maximum speed to reduce fuel consumption and emissions. Because a ship's fuel use rises steeply (roughly with the cube of speed), even a modest speed reduction yields a large fuel saving — making slow steaming one of the simplest and most effective ways to cut both costs and CO₂.
Widely adopted since the fuel-price spikes and overcapacity after 2008, and now reinforced by carbon rules (CII, EEXI), slow steaming lowers fuel bills and improves a ship's carbon rating, and can help absorb surplus capacity across a fleet (more ships needed to maintain a service frequency). Its trade-off is longer transit times, which affect supply-chain speed, inventory and schedule reliability, and very low speeds can strain engines. “Super slow steaming” pushes it further. Slow steaming sits at the intersection of cost, emissions and service, and is a core lever in both voyage economics and decarbonisation.
Because fuel burn scales with the cube of speed, slowing down a little saves a lot of fuel and CO₂ — making slow steaming the cheapest decarbonisation lever there is, and a way to soak up surplus ships. The price is slower supply chains. That cost-emissions-service trade-off makes it a central decision in both voyage economics and green compliance.
Why does slowing down save so much fuel?
A ship's fuel consumption rises roughly with the cube of speed, so even a small speed reduction produces a large fuel and emissions saving.
What is the downside of slow steaming?
Longer transit times, which affect supply-chain speed, inventory and schedule reliability, and possible engine strain at very low speeds.