The sails on today's sailing boats most often have a triangular shape. The surface of a triangular sail is twice smaller than a square sail of the same height and width. By placing square sails on the sailing masts, the masts could be twice as small.
Today, instead of wood, the masts are made of very strong and lightweight composite materials. Such masts can be fixed to the sailboat without the ropes connecting the top of the masts to the sides of the ship. This allows the sails to move freely around the mast, as they do not interfere with the ropes that connect the top of the mast to the sides of the ships. This makes it possible to build square sails that can rotate freely in all directions.
There used to be large sailboats of the cube sails that lifted manually with the sail bearers, but maneuvering such sails was very difficult because of the many ropes that operated with them and kept the mast upright.
The sail shown above can be rotated around the mast, and its surface can be easily changed.
The mast (3) is mounted on a stand (1) which has a bearing (2) with bearings on top. This allows the mast(3) to rotate freely in its bearing (2).
The mast (3) rises above the bearing (2) and has two sails supports (4), one at the top and one at the bottom. Only the sail (7) is located between these sail supports (4).
On the mast(3) there is a tube the for winding sails(5).
It is a pipe that is wider than the mast (3) and which is attached to the mast (3) and is located between the upper and lower mast supports (4). On this tube for winding sails(5) is wound the sail (7) on either side when the sail surface is to be reduced, that is, the sail is unwound on two sides when the sail surface wants to be enlarged.
On the sides of the sail (7) there are lateral sail holders (6) that hold the sail (7) stretched between these holders and the central tube for sail winding (5).
The side sail holders (6) at their top and bottom have loops attached to the upper and lower sail supports (4) and which slide over these sail supports (4). In this way the sail is connected unit with the mast and its surface can be changed from the minimum when it is wound to the of the sail winding (5), or to the maximum when the lateral sail supports (6) are extende windingd to the end points of the sail carrier (4).
The sail is unwound with the help of two elastic cords (9). These elastic cords (9) connect the two sides of the sail (7) passing over two small pulleys (8) located at the very ends of the sail carrier (4).
Two pulleys are located on the upper sail carrier and two on the lower carrier. When the sail (7) is collapsed by winding the sail winding (5), the elastic ropes (9) extend and tighten over the pulleys (8), and when the sail winding (5) is released then the elastic ropes (9) unwind the sail by their elastic tensile force (7) from the sail winder (5).
At the bottom tube for winding of the sail (5) there is a pulley of winding (10) to which the rope of the sail (11) is wound in the direction opposite to that the sails (7). When this rope of the sail (11) is tightened, the pulley pulley (10) is rotated, thus turning the sail winder (5) itself. This causes the sail (5) to be wound on both sides of the sail (5). When the rope of the sails (11) is released then the force of the elastic ropes (9) expands the sails (7), thus turning both tube for winding the sail (5), as well as the pulley of the winding (10). This also winds the rope (11) on the pulley (10). The sail rope (11) can be pulled or released manually from the deck of the ship, and it can also be pulled from the cabin in which the crew is located. It can be pulled or released with the help of an electric motor operated by the captain of the ship.
At the very bottom of the mast (3) there is a worm gear (12) by which the mast (3) can be rotated from left to right, depending on the direction in which the sail (7) is to be positioned relative to the wind. This worm gear (12) can be rotated manually via a manual gearbox, or with an electric motor remotely from the captain's cabin.
Operating the sailboat in this way is much easier than using a large number of ropes. One person can remotely collect or spread the sail, and also the same person can place the remote sail in an optimal position relative to the wind.
This makes sailboat management much easier and less expensive.