A conical textile tube that resembles a giant sock is known as a Windsock. It is identified with a tapered sleeve open at the both ends. FAA provides detailed guidelines of Specification for Wind Cone Assemblies No: 150/5345-27E

Major usage of a Windsock

• Basic guide for recognizing wind direction, strength and speed at airports and helipads
• For wind speed and direction in chemical industries and Refineries.

How fabric plays a role in functioning of a Windsock?

To answer that, firstly it is important to be aware about –

Basic functioning of a Windsock

Windsock is designed in such a way that a metal frame holds the wider end open allowing the air flow in the wider end and exit in the smaller end, with this the orientation of the windsock helps to identify the direction of the wind and the shape of the tube gives an estimate of the wind speed. Windsocks are lit at night with flood lights – either the one mounted on the pole shining inside it or on top surrounding it at many airports.

Real Science behind Windsock functioning

Windsock is installed in the opposite direction of wind; in short, wind direction is the opposite of the direction in which the windsock is pointing, therefore a windsock pointing due north is actually indicating a southerly wind. The Wind speed is indicated by the windsock’s angle which is relative to the mounting pole as per which in low winds, the windsock droops and in high winds, it flies horizontally.

To help estimate the speed of wind, alternating stripes of high visibility color are used where each stripe adds up to 3 knots to the estimated wind speed and on the other hand, some circle frames mountings that makes the windsocks to be held open at one end thereby indicating a velocity of 3 knots. The specialty of the windsock is that it is a standalone system which works without power and displays wind speed directly to pilots and other users whereas anemometers does not show wind speed directly and need a dissemination system to provide the information.

Importance of Wind Sock Fabric as per ICAO and FAA standard guidelines

The standards listed by ICAO and FAA for fabric windsocks explain the importance of fabric upfront with essential functioning facts. As per these reputed authorities,

• The wind cone assemblies must be designed to operate under any ambient temperature between -67°F (-55°C) and 131°F (+55°C) and wind speed up to 75 knots (140 km/hr or 86 mph).
• The fabric windsock must be designed in such a manner that it takes the shape of a truncated cone when filled with air.
• The fabric windsock must be reinforced at all points which are prone to abrasion due to flexing against the metal framework and thus should be designed in such a manner that should allow removal and replacement without the use of stitching.
• The fabric windsock must be constructed in such a way that it should drain out the water.
• The minimum effective length and the throat end opening diameter of the fabric windsock should be 8 feet & 12 feet in length with 18 inches & 36 inches throat diameter respectively.
• The fabric windsock must be designed in such a way that it causes the windsock to fully extend when exposed to a wind of 15 knots or 28km/hr
• The fabric should be made of either synthetic material; cotton or a blend of both with coating over it.
• The fabric should be water repellent.
• The fabric must have a minimum breaking strength considering Warp – 150 pounds and Filling – 150 pounds
• Strong testing methods should be followed to determine the minimum strength of the fabric.

How SGS Windsocks fulfill the ICAO and FAA guidelines?

Along with maintaining general listed standards of ICAO and FAA, our Windsocks comply with the standard fabric design and size options. Our windsock fabric is highly durable in terms of use and color as SGS makes use of Hypalon fabric which is made waterproof with a high quality UV coating that can stay unchanged for a very long life keeping the windsock fabric water resistant easily in rainy season.

• The windsock fabrics of SGS Frangible do not offer any electromagnetic interference and thus does not pose any danger to communication and airline system at airports thereby ensuring safety and no deflection.
• The thickness of the windsock fabric is rightly maintained at SGS along with all cabling and power circuits included in the windsock itself.
• The wind sock fabric of SGS Frangible has a shelf life of up to 6 months to 1 year depending upon the installation area and thus proves to be a complete value for money.

As Wind Sock specifications vary based on the type of use, the SGS Frangible Towers has the ability of offer standardized customization right from windsock framework to its fabric that’s why our windsocks has been successfully tested for –

• Full impact crash test by 3rd party along with Salt Spray+ test thereby proving its authentication.
• Temperature Resistance and Di-Electric Strength test
• Wind Load Deflection and Flammability test
• Flexural Strength; UV Resistance and Tensile Strength test
• Flame Spread & Smoke develop Index

Conclusion

While evaluating the strength and life of windsock fabric, it is important to consider the location for a wind sock. In addition to that, the evacuation lanes along with their routes must be taken into consideration specifically in industrial and agricultural areas, reason being an improper placement of the wind sock could lead to an unsafe evacuation of personnel to a safe assembly area, so SGS Frangible ensures perfect wind sock fabric along with perfect wind sock classifications for all operating environments like airport, Helipads and marine and intelligently provides frangible solutions by defining and simply meeting the regulations for wind sock fabric, wind sock height and size and lastly a satisfactory installation and maintenance which qualifies and proves us as one of the most authentic and reliable provider of frangible structures; accessories; products and quality composite solutions.