How are tower crane types categorized?

Tower crane types are categorized primarily by how they are attached at the base. This classification is critical because it influences the crane's stability, how it operates, and its suitability for different construction scenarios. The attachment methods can include designs such as fixed, climbing, or tethered, which directly affect how the crane interacts with the construction site.

Understanding the base attachment has implications for safety and efficiency. For example, a free-standing tower crane must be anchored correctly to ensure it can handle the loads it is lifting without tipping over. Similarly, climbing cranes are designed to elevate as the building progresses, showcasing their innovative attachment design that accommodates growing structures.

The other options, such as operational speed and aesthetic design, do not fundamentally impact the performance and function of a crane in the same way that the base attachment does. Lifting capacity is an important characteristic but does not define the category of the crane itself—rather, it indicates the crane's maximum potential weight it can handle. Therefore, categorizing tower cranes by their base attachment method is essential for understanding their operational characteristics and applications.