"We refer to the current collector on the top of the tram as the trolley pole. On our site we have two wires above the trams, one for cars running north and the second for cars coming south, but owing to some temporary track issues, at Wakebridge, we have to stop and move the current collector from the north to the southbound wire, before proceeding north to Glory Mine. In doing this the trolley pole is drawn down from one wire, under it, and moved over to over to the next wire. This act is called "ducking the trolley". The signs around site were put up earlier this year to remind crews to duck the trollies and ensure the current collector is on the correct wire. Should a car proceed with the trolley on the wrong wire, there is the risk of a de-wirement at places where the wires diverge, or worse, if approaching another tram, the two-trolley poles would collide."