The role of the catenary catenary contact wire suspension by dropper. Catenary wire can carry a certain current to reduce the impedance of the traction network, reducing voltage loss and energy consumption. Catenary wire material can be divided copper catenary wire, steel catenary wire, aluminum clad steel load-bearing cable. Steel catenary need to take anti-corrosion measures.
 
1 Mg-Cu alloy stranded 
 

2 Copper stranded wire

Solid and stranded (classes AA and A) bare copper are suitable for overhead transmission and distribution applications. Stranded conductor of greater flexibility (classes B and C) are suitable for uninsulated hook up, jumpers, and grounds in electrical construction. Soft drawn copper is unilay construction.