SUMMARY

This research studies the tip-over stability of crawler cranes in heavy lifting applications. Two major applications are discussed:
1. Crawler cranes with movable counterweights:
Crane counterweights provide balancing forces so that the crane does not tip over as it picks up and moves heavy payloads. To increase the stability of the crawler crane and help support a heavier payload, the concept of a movable counterweight is introduced. However, introducing a movable counterweight complicates the static and dynamic analyses of the crawler crane.
This research provides a detailed static and pseudo-dynamic analyses are performed to calculate the limits of the counterweight position to ensure stability and prevent tip-overs for different crane parameters and configurations. Finally, a guideline is given to crane operators to prevent accidents, and define safety regions of operation.
2. Crawler Cranes in Tandem Lifting:
One common problem in crane lifting operations is the need to transport a bulky or irregular-shaped payload. In this case, it is preferred to handle these items by tandem lifting with two cranes. The complexity of such a configuration is discussed, and a static tip-over analysis of the two cranes in tandem lifting operation is studied.
These cranes have a large tendency to tip-over creating bigger catastrophes, since the tipping of one crane causes the other crane to tip as well. Also, it is often difficult to synchronize the behavior of the two cranes since they are operated by two different operators, who often have difficulties perceiving what is going on the other side. Thus it is important to provide a set of guidelines that can simplify the procedure and minimize accidents.