GB2098949A - A method of launching a tethered sail from a ship - Google Patents

Abstract

A method of launching a spar-less sail 4 from a water going vessel involves raising the spar-less sail package 4 above the area of turbulence around the vessel by means of a parachute pilot kite 5 and releasing the sail package so as to inflate and launch the spar-less sail. The pilot kite 5 is launched by a launch gun 3. <IMAGE>

Description

SPECIFICATION Elevated sails and their control The present invention relates to elevated sails and more particularly to the deployment of elevated sails for the propulsion of water going vessels.

The ever increasing cost of energy particularly in the form of increasing oil prices have led to renewed interest in the total or partial propulsion of water going vessels such as cargo ships, tankers and yachts by use of wind energy. In particular, elevated sails or kites which have been proposed and used for the propulsion of ships have certain advantages over, say, vessel mounted sails. These advantages include the ability to fly at an altitude where the winds are generally strong and stable.

Launching of spar-less sails, e.g. ram air wing kites, from a water going vessel is often hindered due to areas of turbulence caused by the action of the wind against the vessel, the resultant downdraught being sufficient to cause ditching of the sail into the water. The present invention relates to a launching technique which alleviates this problem. The use of the term sail is intended to include elevated sails and any tethered flying surface.

Thus, according to the present invention, there is provided a method of launching a spar-less sail from a water going vessel comprising the steps of (a) raising the sail package above the area of turbulence around the vessel by means of an easily launchable sail preferably of the parachute type and (b) releasing the sail package so as to inflate and launch the spar-less sail.

The invention will now be described by way of example only and with reference to the accompanying drawing.

A ship 1 equipped with a winch system 2 has a launch gun 3 powered by compressed air on its deck. The spar-less sail 4 is in the-form of a bundle on the deck and is connected to a pilot kite 5 and to the winch system 2 (Figure (a)).

During launch of the spar-less sail 4, the pilot kite 5 is launched by the launch gun 3 to a height where it is unaffected by downdraughts caused by wind action on the ship 1 (Figure (b)). The pilot kite 5 has sufficient lifting power to carry the spar-less sail bundle 4 into the air to a suitable height. At this height, the spar-less sail bundle 4 is caused to unfurl either by use of a separate control line connected to the deck of the ship or by the pulling action of the pilot kite 5 (Figure (c)).

When the spar-less sail 4 is stable the pilot kite 5 may be left attached or be detached and recovered to the ship's deck.

Claims

1. A method of launching a spar-less sail from a water going vessel comprising the steps of (a) raising the sail package above the area of turbulence around the vessel by means of an easily launchable sail and (b) releasing the sail package so as to inflate and launch the spar-less sail.

2. A method according to claim 1 in which the easily launchable sail is a pilot kite of the parachute type.

3. A method according to claim 1 or claim 2 in which the easily launchable sail is launched from a launching gun.

4. A method according to any of claims 1 to 3 in which-the spar-less sail is released by means of a separate control line.

5. A method according to any of claims 1 to 3 in which the spar-less sail is released automatically by the pulling action of the easily launchable sail.

6. A method according to any of the preceding claims in which the control lines of the sails are attached to a winch or winches.

7. A method of launching a spar-less sail as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Elevated sails and their control The present invention relates to elevated sails and more particularly to the deployment of elevated sails for the propulsion of water going vessels. The ever increasing cost of energy particularly in the form of increasing oil prices have led to renewed interest in the total or partial propulsion of water going vessels such as cargo ships, tankers and yachts by use of wind energy. In particular, elevated sails or kites which have been proposed and used for the propulsion of ships have certain advantages over, say, vessel mounted sails. These advantages include the ability to fly at an altitude where the winds are generally strong and stable. Launching of spar-less sails, e.g. ram air wing kites, from a water going vessel is often hindered due to areas of turbulence caused by the action of the wind against the vessel, the resultant downdraught being sufficient to cause ditching of the sail into the water. The present invention relates to a launching technique which alleviates this problem. The use of the term sail is intended to include elevated sails and any tethered flying surface. Thus, according to the present invention, there is provided a method of launching a spar-less sail from a water going vessel comprising the steps of (a) raising the sail package above the area of turbulence around the vessel by means of an easily launchable sail preferably of the parachute type and (b) releasing the sail package so as to inflate and launch the spar-less sail. The invention will now be described by way of example only and with reference to the accompanying drawing. A ship 1 equipped with a winch system 2 has a launch gun 3 powered by compressed air on its deck. The spar-less sail 4 is in the-form of a bundle on the deck and is connected to a pilot kite 5 and to the winch system 2 (Figure (a)). During launch of the spar-less sail 4, the pilot kite 5 is launched by the launch gun 3 to a height where it is unaffected by downdraughts caused by wind action on the ship 1 (Figure (b)). The pilot kite 5 has sufficient lifting power to carry the spar-less sail bundle 4 into the air to a suitable height. At this height, the spar-less sail bundle 4 is caused to unfurl either by use of a separate control line connected to the deck of the ship or by the pulling action of the pilot kite 5 (Figure (c)). When the spar-less sail 4 is stable the pilot kite 5 may be left attached or be detached and recovered to the ship's deck. Claims

1. A method of launching a spar-less sail from a water going vessel comprising the steps of (a) raising the sail package above the area of turbulence around the vessel by means of an easily launchable sail and (b) releasing the sail package so as to inflate and launch the spar-less sail.

2. A method according to claim 1 in which the easily launchable sail is a pilot kite of the parachute type.

3. A method according to claim 1 or claim 2 in which the easily launchable sail is launched from a launching gun.

4. A method according to any of claims 1 to 3 in which-the spar-less sail is released by means of a separate control line.

5. A method according to any of claims 1 to 3 in which the spar-less sail is released automatically by the pulling action of the easily launchable sail.

6. A method according to any of the preceding claims in which the control lines of the sails are attached to a winch or winches.

7. A method of launching a spar-less sail as hereinbefore described with reference to the accompanying drawings.