Rotor sails are cylindrical mechanical sails that spin which can reduce shipping fuel use by 7-10%

Two 30-meter tall Rotor Sails have been installed onboard the product tanker vessel Maersk Pelican targeting a reduction in fuel cost and associated emissions on typical global shipping routes of 7-10%.

Norsepower Oy Ltd., together with project partners Maersk Tankers, Energy Technologies Institute (ETI) and Shell Shipping & Maritime, today announced the installation of two Norsepower Rotor Sails onboard Maersk Pelican, a Maersk Tankers Long Range 2 (LR2) product tanker vessel.

The Rotor Sails are large, cylindrical mechanical sails that spin to create a pressure differential – called the Magnus effect – that propels the vessel forward. The Rotor Sails will provide auxiliary wind propulsion to the vessel, optimising fuel efficiency by reducing fuel consumption and associated emissions by an expected 7-10% on typical global shipping routes.

27 thoughts on “Rotor sails are cylindrical mechanical sails that spin which can reduce shipping fuel use by 7-10%”

  1. It’s a fixed device, not deployed, so no crew handling generally, just spin direction and speed controls. Since it is a fixed object on the superstructure, there’s no direct safety hazard to crew during operation and it won’t interfere with nearby ships. The big drawback is wetted area aloft with a moment arm, so side winds causing the ship to heel over could be dangerous. Kitesails could provide more propulsive power than rotorsails, but require a deployment/retrieval mechanism, and some sort of flight control. Modern cargo ones generally try to simplify this with a single line to a control pod device, from which 4 lines run to the corners of the parasail to control thrust direction. Control pod is radio linked usually. Since it is pulling on a single line, there is less moment arm to cause heeling (depending on the placement of a deployment mount). Kitesails can be very large to provide substantial thrust, and can fly figure-8 patterns to increase apparent wind to further increase thrust. However, since they are essentially an unwieldy kite, you have a deck operation safety issue with the tether line for crew, and a proximity issue to nearby traffic (risk of unexpected movement due to changes in wind, and wrapping the kite/tether around another ship).

  2. It’s a fixed device not deployed so no crew handling generally just spin direction and speed controls. Since it is a fixed object on the superstructure there’s no direct safety hazard to crew during operation and it won’t interfere with nearby ships. The big drawback is wetted area aloft with a moment arm so side winds causing the ship to heel over could be dangerous. Kitesails could provide more propulsive power than rotorsails but require a deployment/retrieval mechanism and some sort of flight control. Modern cargo ones generally try to simplify this with a single line to a control pod device from which 4 lines run to the corners of the parasail to control thrust direction. Control pod is radio linked usually. Since it is pulling on a single line there is less moment arm to cause heeling (depending on the placement of a deployment mount). Kitesails can be very large to provide substantial thrust and can fly figure-8 patterns to increase apparent wind to further increase thrust. However since they are essentially an unwieldy kite you have a deck operation safety issue with the tether line for crew and a proximity issue to nearby traffic (risk of unexpected movement due to changes in wind and wrapping the kite/tether around another ship).

  3. It’s a fixed device, not deployed, so no crew handling generally, just spin direction and speed controls. Since it is a fixed object on the superstructure, there’s no direct safety hazard to crew during operation and it won’t interfere with nearby ships. The big drawback is wetted area aloft with a moment arm, so side winds causing the ship to heel over could be dangerous.

    Kitesails could provide more propulsive power than rotorsails, but require a deployment/retrieval mechanism, and some sort of flight control. Modern cargo ones generally try to simplify this with a single line to a control pod device, from which 4 lines run to the corners of the parasail to control thrust direction. Control pod is radio linked usually. Since it is pulling on a single line, there is less moment arm to cause heeling (depending on the placement of a deployment mount). Kitesails can be very large to provide substantial thrust, and can fly figure-8 patterns to increase apparent wind to further increase thrust. However, since they are essentially an unwieldy kite, you have a deck operation safety issue with the tether line for crew, and a proximity issue to nearby traffic (risk of unexpected movement due to changes in wind, and wrapping the kite/tether around another ship).

  4. what you want is probably en. wikipedia. org/wiki/Magnus_effect Think of the effect of off-axis spinning on musket balls, or a more obscure application the Baseball “curve ball”.

  5. what you want is probablyen. wikipedia. org/wiki/Magnus_effect Think of the effect of off-axis spinning on musket balls or a more obscure application the Baseball curve ball””.”””

  6. what you want is probably

    en. wikipedia. org/wiki/Magnus_effect

    Think of the effect of off-axis spinning on musket balls, or a more obscure application the Baseball “curve ball”.

  7. NBF should do an article on the company Climeon and the waste heat recovery system they are building. This is a rare success story and the technology is fascinating. They can use low grade waste heat differentials and extract useful power. It is already used on big ships and it must be a lot more efficient than sails. Cant link here unfortunately. Search on climeon and then click “industries->maritime” c l i m e o n . c o m / m a r i t i m e

  8. NBF should do an article on the company Climeon and the waste heat recovery system they are building. This is a rare success story and the technology is fascinating. They can use low grade waste heat differentials and extract useful power. It is already used on big ships and it must be a lot more efficient than sails.Cant link here unfortunately. Search on climeon and then click industries->maritime””c l i m e o n . c o m / m a r i t i m e”””

  9. Flettner rotorsails are starting to become a thing. There was that nordic ferry recently that had one stuffed on top. Getting two onto that Maersk cargo ship is pretty good. There was that Greenpower one where 4 were fitted on a wind turbine transport and installation vessel in Germany as well. I can see the appeal over kitesails.

  10. Flettner rotorsails are starting to become a thing. There was that nordic ferry recently that had one stuffed on top. Getting two onto that Maersk cargo ship is pretty good. There was that Greenpower one where 4 were fitted on a wind turbine transport and installation vessel in Germany as well. I can see the appeal over kitesails.

  11. NBF should do an article on the company Climeon and the waste heat recovery system they are building. This is a rare success story and the technology is fascinating. They can use low grade waste heat differentials and extract useful power. It is already used on big ships and it must be a lot more efficient than sails.
    Cant link here unfortunately. Search on climeon and then click “industries->maritime”

    c l i m e o n . c o m / m a r i t i m e

  12. Flettner rotorsails are starting to become a thing. There was that nordic ferry recently that had one stuffed on top. Getting two onto that Maersk cargo ship is pretty good. There was that Greenpower one where 4 were fitted on a wind turbine transport and installation vessel in Germany as well. I can see the appeal over kitesails.

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