Railway track workers install and maintain railway tracks, and also make regular inspections of existing track. They are also responsible for the care of the ground at the side of the track, cutting back vegetation, the upkeep of any drainage systems, bridges and crossings etc. Overhead line workers install and maintain the power supply system for the trains. They also carry out regular inspection of the lines and repair any weather damage, for example from lightning. They must be particularly safety-conscious, carrying out repair work only when the power has been switched off, for instance. Track and line workers use a variety of tools and machinery to assist them in their work.