The wires on the high-speed railway are called overhead catenary. They are put into the air by the brackets on both sides of the track, and then contact with the pantograph on the high-speed railway to transmit power to the high-speed railway.
Usually, we see two wires on the high-speed railway, one above and one below. In fact, the only real power transmission line is the one below, that is, the real wire. The wire above is used as a 'suspension wire' so that the wire can be better connected with the pantograph in the air.
This' suspension line 'is called a messenger cable. Because of its special design, it can suspend the wire without affecting the contact with the pantograph on the high-speed railway.
In other words, the wire is not 'tied with a rope and tied to the suspension line', but 'sucked' by the connecting wire hanging from the messenger cable, so there is nothing below the wire to hinder its contact with the pantograph.