Sailboats are vessels or boats powered by power wind. In the past, they were the most common type of vessel, while today they are used most on recreational yachts and sports vessels, but more recently on transport vessels for save fuel.
Naw typically, such vessels have built-in engines that start them when there is no wind.
While they are driven by power wind, they do not have to consume engine fuel and are therefore very economical. They can navigate seas, and deeper rivers, and their only restriction is bridges below which they cannot cross, and therefore become very rare on most rivers.
To pass below the bridges, they cannot pass due to the high mast height of the sails.
To get under the bridge they would have to position the mast in a horizontal position, which is only possible with small sailboats where one man can lower the mast.
On larger sailboats, the mast is mounted in the mast base by means of large cranes, and the mast can not be lowered or raised during navigation. The mast post is installed inside the upper deck itself, which must be strong enough to withstand all loads acting on the sails and mast.
The problem of speed of lifting and lowering can be easily solved by different placement of the mast stand on which the mast is mounted, and by different construction of the bottom of the mast.
The mast stand (1) is located above the upper deck, and at the top of the stand there is a berth (3), on which the mast (2) is placed, that is, a small shaft built into the mast itself at its bottom. This shaft rotates in the bearing (3) when lifting and lowering the mast as seen laterally in Fig. 1 and Fig. 2, or from above in Fig. 3.
At the very bottom of the mast (2) there is a small pulley (4), and two more such pulleys are located on the deck below the mast. These three pulleys are connected by a rope (5) extending over the pulleys (4). With the pull of this rope (5) the distance between the pulleys (4) is reduced and the mast (2) is raised in a vertical position relative to the vessel.
By releasing the rope (5), the mast (2) is lowered to a horizontal position. Before lowering the mast (2), it is necessary to open the clamp (6) which holds the mast in a vertical position.
Thanks to this innovation in mast placement, it is possible to lower the mast quickly and easily during horizontal sailing. Before passing under the bridge, the ride is switched to the motor and one or more masts are lowered to the horizontal position. 4th
After passing under the bridge, the masts are re-positioned in a vertical position, and the clamp (6) on each mast stand is re-assembled and secured so that the masts are firmly connected to the mast stand. After that, the sailboat can start again with the help of the wind.