Centuries ago the Japanese were the first to use windsocks. They were originally hung on a tall bamboo pole on “Boys Day”, to celebrate all the male offspring. One was flown for the father of the house, and one for each of his sons. The father’s windsock was often black, and the eldest son was red, and one was represented for each additional son in other bright colors. They were also flown to celebrate the birth of a son. These first windsocks were made in the shape of a koi fish, and were called koi noburi. They were made out of paper or silk, and were embossed with the family crest. Affluent Families had the means to be able to make theirs out of silk.
History shows that Romans also used windsocks as far back as 105 A.D. for military banners. It is believed that they were used to represent different military groups.
In 1800’s “wind-sails” were used to funnel air down to the lower compartments of a ship. They were shaped like a wide tube or funnel made out of canvas. It is believed the windsock was fashioned after the wind sail, and was later recreated for the use of airplanes to help determine wind direction and speed. Now they are a common site at airports, and you may sometimes see them along roads and highways at windy locations.
You may see a windsock flying at a chemical plant where there is risk of gaseous leakage. They are not used to determine a chemical leak, but is used to help determine which direction and how strong the wind is blowing. In the event of a leakage this would help determine how far and fast the contaminants would travel. And would help in determining an evacuation zone.
To determine the wind direction from a windsock; the wind is originating from the opposite direction the windsock is pointing. So if a windsock pointing north, this indicates the wind is coming from the south. When determining wind speed, it is indicated by the windsocks angle in conjunction to the pole it is hung on. When the winds are strong it flies horizontally, and in a light breeze the windsock droops. Airports have special FAA (Federal Aviation Administration) certified windsocks. FAA standards state that at 15-knots (25 km/ 17 mph) the wind will fully inflate a properly functioning windsock. A 3-knot (5.6 km/3.5 mph) as the minimum wind speed to cause it to move, or minimum wind speed to cause it to orient itself in accordance to the wind. To be effective they need to be put up high on a pole, so it can move about freely in the wind, and it is also more visible. It is common at airports to have windsocks lighted at night, typically with flood lights. Either on the pole causing the light to shine inside it, or on the ground surrounding it.
Windsocks are also a popular yard ornaments, and are usually a hit with children. They are also fun and easy to make. A great starter sewing project for a student new to sewing, because they are bright and colorful and easy to make. Decorative windsocks are more for decoration and are not highly effective, but they can be used to determine a general idea of wind speed and direction.