What is the function of an “expansion joint” in power lines?

The function of an expansion joint in power lines is to allow for thermal expansion and contraction. As temperatures fluctuate, materials can expand when heated and contract when cooled. In power lines, these changes in temperature can create stress on the structure and connections. The expansion joint acts as a flexible point, accommodating these movements and preventing damage to the electrical components, such as conductors and insulators. This design feature ensures the integrity and reliability of the power transmission system by mitigating the risks associated with thermal stress, ensuring that the system can reliably function across a range of environmental conditions.