Instead of a traditional sail fitted to a mast, SkySails uses large towing kites for the propulsion of the ship. Their shape is comparable to that of a paraglider. The towing kite has a sail area of over 300m2 and is made of high-strength and weatherproof textiles.

Their double-wall profile gives the SkySails towing kites aerodynamic properties similar to the wing of an aircraft. Thus, the SkySails system can operate not just downwind, but at courses of up to 50° to the wind as well.

The fact that SkySails towing kites regularly fly at speeds of up to 200 kilometers per hour during normal operations means they can easily withstand storms.

The tractive forces are transmitted to the ship via a highly tear-proof and very lightweight synthetic rope made of Dyneema. The energy supply of the kite steering mechanism – the control pod - is ensured by means of a patented special cable integrated in the towing rope.

The tractive force of the SkySails-System is directed to the bow area over the force transmission point mounted on the foredeck. Generally the existing ship‘s structures are sufficiently dimensioned, since that is where the anchor windlass is also housed. The power transmitted by the SkySails system is comparable to that of an ocean-going tug. An appropriate stability computation is made for each vessel prior to the installation of a SkySails propulsion.

The SkySails towing kite is recovered and launched using a dynamically operating winch, which also serves as rope storage. The tractive force measurement is pre-installed in the winch. The winch speed is chosen so that the towing kite can be stabilized at any time when wind conditions are unstable. During heavy swell the winch assures safe operation during the launch & recovery procedure by means of dynamic sea-state compensation.


The towing kite is double-walled and fitted with chambers along its entire length as well as ports at the front end. A line tree defines the requested kite shape by spanning lines of different lengths between the control pod and the towing kite. The profile of the towing kite is designed in such a way that optimal aero-dynamic efficiency can be achieved.


The "force transmission point" - also called "tow point" - is the point at which the towing rope of the kite is connected to the ship. The tow point guarantees the optimal alignment of the kite's power for every course and wind direction.