We tend to think about wind mostly during crane operations, however there’s another side to it and it is when the cranes are parked or out of service. The news this week from Vertikal brought two stories of two crawler cranes collapsing due to wind gust and probably out of service.
Fortunately no one was injured in these two accidents.
There are many reasons why this can happen, and when it comes to wind there are three main reasons that tend to repeat:
These can be easily 2 or 3 times the average wind speed. If our wind speed meter shows normally 40mph quite continuously, it can be no surprise to see a wind gust of double that wind speed. You can see an example of this below
If we look at the example below where the average wind speed is 20mph and suddenly we get a wind gust of 40mph, this does not mean that the wind load on the crane is just double, in fact it will be 4 times the wind load. More information on wind forces here: https://www.windcrane.com/anemometer-wind-crane
Besides the wind load, there’s also the position of the load in reference to the crawler itself, for example if the crane is lifting a load pointing North and the wind comes from the South, then the risk of a wind gust tipping the crane is much higher than if the wind was coming from the North. For this it is best to consult the guidelines of the crane manufacturers.
This is one that we hear more often, when cranes are parked or not operating during the night. Wind is very variable and difficult to predict since the surroundings impact the force of the wind. A crane can be left with the boom partially retracted or parked for what it could be a normal night, only to have a sudden drop of atmospheric pressure and the wind starts to pick up very quickly. In the case of a crawler crane, it is a lot more difficult to leave the boom freewheeling like a tower crane.
This is one of the reasons we developed WINDCRANE to be extremely energy efficient so it can run form the crawler crane batteries for days without depleting the vehicle batteries. In fact, the WINDCRANE consumes so little that it can be powered from the same air-traffic lights from the crane, without the need to use a boom wiring.
WINDCRANE is a live system, and we have helped a lot of crawler crane operators to keep in contact with their cranes even when no staff is on site since all the data is transmitted real time over the GSM network without the need of any base station.
Most of our systems are often used for weather claim conflicts and maximising lifting time, however our main core priority is always safety and this is the reason we always provide remote live access and instant notifications to all our customers of the wind speed surrounding their crane fleets. Not only that but we can provide wind forecast for any crane with corrected height wind calculation and the potential of high wind risk disruption to the project on a weekly basis.