What is the necessary method for bonding plates to a steel column?

The bonding of plates to a steel column can be achieved through multiple methods, including welding, brazing, and bolting, making the choice of "all of the above" valid. Each method has its unique characteristics and applications based on the specific requirements of the project.

Welding creates a strong, permanent bond by melting the base materials, providing excellent electrical conductivity and structural integrity. This method is often preferred in situations where high strength and durability are critical.

Brazing involves melting a filler metal to join the plates to the column, which can be advantageous in scenarios where heat-sensitive components are present, as brazing allows for lower temperatures than welding. This method can also provide good electrical connections when done correctly.

Bolting, on the other hand, is a mechanical method of attachment that allows for easier assembly and disassembly. It is widely used for its convenience in construction and maintenance situations, and it can accommodate thermal expansion differences between the components.

Since all these methods can effectively bond plates to a steel column, the answer indicating that any of them may be suitable aligns with the principles of good engineering practices in lightning protection systems and structural integrity guidelines.