Q.: We have been cautioned against using too large a crane on a tilt-up job. What is the disadvantage and what harm could it do?
A.: Suppose the job calls for a 60-ton crane but that you have been keeping a 140-ton crane available because it is fast and efficient, and you decide to use the large crane. Suppose, then, that the bond breaker isn't working right and the panels stick. If the crane rigger comes up too close to the panel, it will stick when he tries to lift it and he will rip it apart because he is overcraned.<</p>
If the large crane must be used, the thing to do is to keep the stress away from the panel. If instead of working at a 15-foot radius the operator gets back to a 25- or 30-foot radius, there will be no problem. Now if the bond isn't breaking the way it should, the front end of the crane rears up. This prevents the crane from cracking the panel.