Rigging for wind
10 January 2019
Know the wind. It’s a simple but profound statement for crane operators. The fact is that wind is the second most common cause for crane accidents worldwide. The American National Standards Institute (ANSI) reported that “between 2000 and 2010, there were 1,125 tower crane accidents reported worldwide, resulting in more than 780 deaths. One of the main culprits behind these tragedies was exposure to wind, which caused 23 percent of all accidents.”1
While being able to track wind speed is important, ANSI stresses, “…the primary concern related to the forces that wind exerts on a tower crane’s load is not the speed of the wind, but its pressure. Wind pressure varies as the square of the wind speed, so, as wind speed doubles, the wind pressure increases by a factor of four times. This means that a small increase in wind speed can severely threaten the safe performance of a tower crane1.”
Even a small increase in wind speed can threaten the safe performance of a crane.
So how can an operator effectively and accurately track the atmospheric changes impacting their work environment? One answer may be the TriSonica Mini, a three-dimensional ultrasonic anemometer that can fit in the palm of your hand.
The TriSonica Mini uses ultrasonic measurements to tell users exactly how fast the wind is moving – from the lightest breath to a stormy gale – and in what direction it moves: up, down, front, back or sideways. It also tells the temperature of the air, the compass heading relative to the device, the moisture borne in the wind, the density of the air and dew point, according to the manufacturer.
Ease of use
While cup-and-vane anemometers come in a variety of sizes, they can suffer the drawbacks of inertia (insensitivity to changes due to mechanical resistance) and wear (bearings and components). With the TriSonica Mini there are no moving parts to wear out or replace, eliminating maintenance issues. The TriSonica Mini can be easily mounted to a crane with a variety of mounting options, and information captured about the wind is output digitally to the operator’s interpretive device. In short, the TriSonica Mini was designed to assure operators know the wind.
According to Anemoment, the TriSonica Mini is an accurate and durable tool that has been deployed for atmospheric monitoring, weather reporting and ecosystem research worldwide. Users include NASA JPL, US Navy, NOAA, NCAR, USDA, DOD, leading engineering and research institutions around the globe such as University of Kentucky, University of Melbourne, University of Virginia, University of Oklahoma, as well as companies, big and small, that need to accurately understand what the wind is doing at any specific time.
The safe operation of tower cranes on a jobsite is never something to be taken lightly. Liability issues alone can be astronomical in the event of a crane failure during times of high winds. Investing in a reliable, accurate and robust ultrasonic anemometer will take the guesswork out of knowing real-time wind conditions. Peace of mind comes from knowing the wind. Additional information on the TriSonica Mini can be found at www.anemoment.com.
1 Kelechava, Brad (2016, July 7). Wind Effect on Tower Cranes. Retrieved from https://blog.ansi.org/2016/07/wind-effect-on-tower-cranes/.