sailing
Ever since early sailors used square sails to help add speed to their oars, the sailboat has become increasingly more complex. The type of construction varied with the availability of materials. Wood was a common material, but was not available in areas like Lake Titicaca where the boats and sails both were constructed of reeds from the shoreline. When iron and steel became available, wood was replaced for the most part. And finally, the invention of steam removed sailing, for the most part, from daily shipping. Today sailing is enjoyed as recreational, and racing has become a very publicized event. To understand modern theory, you must first look at the development of sailing in the working boats of old. Early developers knew that the speed of the boat was proportional to the size of the sail. They put huge sails on boats in efforts to speed shipping. Yet, the size of these sails were so large they became unmanageable without mass amounts of crew. Where labor was cheep, the Far East, huge sails were fitted, but for the rest of the world, a knew solution needed to be found. Sails became split into smaller units and ships carried more masts. Some ships had as many as seven masts and forty nine sails set at once.
Today modern technology and mathematics join together to create boats that fit the formulas. Everything about to be described effects another characteristic of the boat's handling and capabilities. The forces the sail must overcome are important to the motion of the boat. In the theory of sail, four forces are exerted at 900 to each other. Diagram C shows the relationship and placement of the forces and their interaction. When any force exceeds drive, the boat will not move forward. The center of effort, or CE, is the geometric center of the set sails. The center of effort is the balance point of the sails and is very important to the speed of the craft. Also, the center of lateral resistance (CLR) aids in proper sail trim and boat balance. This is the center of all underwater portions of the boat. Without these areas in balance, the drive, forward motion, of the boat would be lost. The keel is most probably the most important part of a sailboats forward momentum. The keel prevents sideways motion, drift. The keel produces a drag and drive from the flowing water and the angle of the keel in the water from the heeling boat produces side force or resistance. A successfully designed and sailed boat balances these forces in such a way that there is a surplus of forward motion. Now that basic hydro-dynamics have been covered, the wind and sails are still left to discuss. Air moves in parallel streams that are very difficult to deflect. Low pressure air is far less dense than a high pressure area. A sail will achieve a low pressure area on the convex side giving it maximum lift. A sail is the same as a sideways airplane wing. On diagram A below, a sail is shown in its airstream. The air moves faster over the convex portion making a low pressure area. Diagram B shows how the sail starts to lift and push forward when the wind flows across. It was Archimedes who first saw that a boat would displace its own weight in water. Based on this, ratios developed based on various areas of underwater hull, and areas of cubes with the same dimensions. The most important being the waterplane coefficient. This is the ration between the underwater plane of the boat and a rectangle having the same length and width. These along with various other, and more complicated,
Some common words found in the essay are:
Lake Titicaca, America's Cup, Cup Zealand, , air moves, forward motion, speed wind, low pressure, times speed wind, sideways airplane wing, sideways airplane, motion boat, boat balance, righting lever, move forward, wind sails,
Approximate Word count = 1534
Approximate Pages = 6 (250 words per page double spaced)
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