The upper edge of the jigss is the highest technical achievement of sail power, but it is a bit out of time. By the time the top-edge jigsaw sail reached its peak, it was already the late 19th and early 20th centuries.

By this time, steam engine technology had long since matured, and even steam turbines appeared. In the early 20th century, the upper edge of the girder sail was mainly used in clipper boats. After all, the sail power does not need to be equipped with coal, which is more economical and can save cargo space. In addition, the speed of the clipper ship, at the beginning of the 20th century, was no slower than that of an ordinary merchant ship with a steam engine......

However, a series of accidents that followed cast a shadow over the sailing ship. Coupled with the emergence of more advanced and efficient diesel engines, the clipper driven by the upper edge of the inclined truss sail finally withdrew from the stage of history.

So, what kind of accident is it? It turned out that 10 Skuna sailing ships of 6 masts and over 6 masts built in the early 20th century (clippers with upper edge cross sails) sank several of them, including the unlucky "Wyoming" 10,000-ton clipper ship mentioned earlier......

Then, people were so swayed by the high accident rate that they eventually abandoned clippers with upper edge jirs. But Marin had read history and knew that he couldn't really blame the upper edge of the birder sail for being bad. Rather, the masted upper edge of the bore-boom sail and the clipper do not match......

Why? Because Marin thinks that the clipper boat is too "thin". Its length-to-width ratio of 6:1 or even higher makes the clipper hull extremely "thin". And a boat that is too thin brings the danger that it can easily roll over.

The upper edge of the oblique truss sail is a longitudinal sail, and most of the borrowing is the side wind. But the wind from the side, while pushing the boat forward, will also push the sailboat to the side at the same time......

If the wind is light, it is fine, but in the event of a big storm, a "skinny" clipper with up to 6 upper edge girder sails will naturally be very easy to roll over......

Moreover, the luck of this Skuna six-masted flying clipper ship was very bad. Why? Because shortly after they withdrew from the stage of history, a technique called "stabilizer fin" appeared and put into use......

What is a stabilizer fin? It is to install artificial "shark fins" on the underwater part of the hull to ensure better balance of the hull. Modern warships, in fact, are no less "thin" than flying clippers, and even surpass them. For example, the "052D" destroyer, which is 157 meters long and 19 meters wide, has a length-to-width ratio of up to 8.26, and is twice as fast as a clipper. But why don't modern warships capsize? Because they all have "artificial shark fins" - stabilizer fins. Moreover, not just one pair, but many pairs......

In this way, even at a speed of more than 30 knots, a modern warship is still as stable as an old driver......

The six-masted clipper ship withdrew from the stage of history before the stabilizer fin technology matured and was put into use, so it is a pity. If a few pairs of "shark fins" were installed, it would not be as if the 10 ships sank several ships......

Moreover, the upper edge of the inclined truss sail was not eliminated, but was retained by modern sailboats. However, most modern sailing ships are small sailboats, sloops, mainly used for sailing. The modern sailing boats that Marin had seen in his previous life basically used an upper edge jigs, and then put a soft auxiliary sail in front of it to make the most of the wind......

……

So, where did the upper edge jigss sail come about? Marin had read the history of navigation in his previous life, and it was introduced above......

The book says that in the 17th and 18th centuries, it was extremely inconvenient to operate the Latin spinnaker when changing directions. In order to make it easier to turn the boom, the first half of the latin sail (i.e., the lower edge of the boom) was cut off.

However, in this way, the Latin spinnaker lost half of its boom, the area of the spinnaker was also halved, and the ability to harness the wind was greatly reduced.

So, people began to think of a way, at the mast level, to get a wind pole that could rotate around the mast. The wind lever is perpendicular to the mast and is connected to the bottom of the mast with a metal collar. In this way, the sailor can pull the wind lever directly in the horizontal direction with his hands or rope.

The upper edge of the girder, which has been retained, is also connected to the mast by a metal collar. However, unlike the wind pole, the wind pole is perpendicular to the mast, and there is an angle between the upper edge of the girder and the mast, and its angle is still the same as when the lower edge of the cross was retained.

As for the sails, they are drawn between the wind bar at the bottom and the upper edge of the boom above. In this way, the sail shape becomes a rectangle with a right triangle on top. The area of a square of the same height and width is twice that of a triangle, so that the area of the upper edge of the new type of blizzle is no smaller than that of the Latin sail with the lower edge of the birder retained. What's more, a right-angled triangular jib can also be added to the top of the upper edge of the jirs, which further increases the sail area and strengthens the wind capacity.

Moreover, the maneuvering of the sails is unusually simple. When the wind changes, the sailor only needs to rely on the winch rope to control the direction of the wind pole on the lower edge of the upper edge of the diagonal truss sail, so that it can rotate in the opposite direction with the mast as the axis. Even, one or two sailors can easily handle the reversal of an upper edge jigs, and in a very short time.

Unlike a schooner, since the sail is lowered from the upper boom, every time the ship is sailed, the sailor needs to climb the sail dozens of meters high to lower the sail and tie it firmly. It is also very troublesome to collect the sails, which require sailors to climb the mast dozens of meters high, first untie the lower end of the bound sail, and then retract it, retract it and tie it to the upper sail truss......

Such an operation, when the wind is calm, is nothing. But if there is a storm suddenly, it will be miserable.

Because, storms at sea often carry heavy rain. If the sails are not quickly stowed, the ship may be overturned by a violent storm. However, the sailor needs to climb up and untie the lower end of the sail, and then retract it upwards. It's nothing to climb the mast in normal times, but it's very dangerous to climb the mast during a storm. Because, the mast stained with rain is relatively slippery. If you are not careful, you can fall from a mast tens of meters high and you may fall to your death on the spot......

So, in the Age of Discovery, sailors who fell from the mast and fell to their deaths were many ...... every year

The upper edge of the jigwir, on the other hand, is different because, like the Chinese stiff sail, it rises from below, like raising the national flag. In the event of a storm, simply untie the rope under the mast and lower the upper edge of the girth sail. Even the upper edge of the rung can be lowered with it......

The bottom of the upper edge of the jigsaw sail is generally connected to the wind pole (which can also be removed), while the end of the edge near the mast is connected to the mast by a number of copper rings that hold the mast together.

When the sail is raised, the sailor pulls the top of the upper edge of the boom sail up by pulling the pulley. First, the top of the spinnaker on the upper edge of the girder, and after the spinnaker above is straightened, the upper edge of the mast that is sleeved by the metal ring rises together until the upper edge of the girder reaches the top, and the main sail below is basically straight (generally not too tight, because it has to be driven). Then, tie the rope, fix it, and start turning the wind lever to adjust the direction according to the wind direction......

What the? How do you say keep the wind bar and the upper edge of the boom on the same plane? It's very simple - just make a vertical rail on the wind lever. In addition to the mast covered with a metal ring, the upper edge of the oblique truss should also be sleeved with this guide rail parallel to the mast...... In this way, it can be fully guaranteed that the wind rod and the upper edge of the diagonal truss are on the same plane. Moreover, it does not affect the rise and fall of the upper edge of the girder......

……

Fearing that the ship would run aground or run aground in the Strait of Magellan, Marin decided to introduce the advanced and easy-to-handle top-edge boom sail to Arben's fleet.

As for the shipwreck of a clipper ship with multiple upper edge cless sails, Marin felt that as long as he did not die, he could install multiple upper edge boom sails on a very "thin" clipper ship......

Moreover, at present, Marin does not have a very "thin" clipper in his hand. There should be no danger in using an upper edge jisper sail on a ship with an aspect ratio equal to or less than 4 to 1, and the number of masts not exceeding 3.

What's more, even if the presence of the upper edge of the blith sail affects the lateral stability of the ship, it is nothing, at most, to install a pair of simple stabilizer fins for the hull underwater...... Marin knows, in the previous life encyclopedia - for ships with a displacement of less than 1,000 tons, it is enough to install a pair of stabilizer fins......

But there are no ships in Marin's current hands with a displacement of more than 1,000 tons, and even very few of them are 500 tons. Therefore, when installing stabilizer fins, there is no need to install any modern stabilizer fins that conform to the hydrodynamics, and it is enough to balance a pair of ordinary stabilizer fins that are symmetrical on both sides.

Besides, Marin felt that as long as he didn't make clippers with upper edge jirst sails, maybe he wouldn't be able to use stabilizer fins. After all, stabilizer fins are used to balance fast boats. The ships that Marin had in his hands were not fast, and they were relatively wide, and there was no need for stabilizer fins......