Tower cranes are phenomenal tools of efficiency. They allow for construction work at severe heights. IN few cases, during the construction of high-rise and sky crappers, the tower crane paves its sky-bound path: as it draws higher levels of a building above itself. A tower crane supplier enables the crane in a way that it is elevated to the higher levels through a hydraulic cylinder present at its base. At higher elevations, a tower crane is exposed to a large number of dangers which make it susceptible to accidents. From 2000 to 2010, there were around 1100 accidents happened due to tower cranes; reported from around the world. The accidents turned out to be 780 deaths approximately. One of the significant reasons behind those tragedies were the wind exposure that caused around 23 per cent of all the incidents.
At lower atmosphere, wind speed usually increases, along a gradient as height grows. Meanwhile, the fundamental issue related to the forces which wind exerts on the crane’s load is not the speed that wind typically has, actually its pressure. Wind pressure differs in line with the wind speed. So, as the speed of wind doubles, the wind pressure goes up via four times factor. This suggests a sharp increase in wind speed can threaten the safe performance of the tower crane severely.
In the manuals, the majority of the tower crane manufacturers suggest the speed in which they should cease the operations to bar unusual hazards. The maximum value is typically 45 mph (20 meter per second). As per ISO 4302:2016, the maximum speed for wind, for all kinds of installed cranes (in the open) should be 20 meters per second. However, this value can be higher in specific transporter type up loaders which are made for high wind exposure. The value for which is 28.5 meter per second.
Since the value of optimal permissible pressure and speed can differ depending upon the particular use of tower crane, the tower crane supplier must convey that information to the buyer and end-user of the crane. As per ISO 9374:2014, manufacturers should measure the max. Wind speed in which the tower crane is resistant to slide, along with precautions which could be made while higher speeds, and handover the information to the customer.
Through careful adherence of the international standards together with tower crane supplier’s instructions, can save precious lives during the construction of high-rise buildings.