What distinguishes an automatic crane?

An automatic crane is characterized by its ability to operate through preset cycles once activated. This means that, after the initial setup and activation, the crane can execute a series of movements or tasks without the need for constant human intervention. This autonomous function allows for increased efficiency and precision in lifting and transporting materials, making it an ideal choice in various applications, particularly in manufacturing and facility operations.

The other options do not accurately describe the nature of an automatic crane. For instance, stating that it can only be operated manually contradicts its automatic functionality, while requiring constant human guidance undermines the efficiency benefits that come with automation. Lastly, mentioning a maximum height restriction does not pertain to the definition of an automatic crane but might refer to specific operational limits, which are not inherently related to its automatic features. Thus, the distinguishing factor of an automatic crane lies in its ability to execute tasks through preset programming, setting it apart from manually operated cranes.