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Re: Trolley Poles and Pantographs
Author: Max Wyss
Date: 10-13-2015 - 14:11
Whether trolley poles or pantographs (or bows) are used depends on the way the wires are set up.
Pantographs require no obstruction below the middle of the wire, but allow an easy change of the wire (as we have in a tensioned catenary. The wires over switchwork can be simple wires suspended in parallel at the same height for a few meters.
Trolley poles allow for suspensions coming below the wire a few centimeters besides. On the other hand, they require a uninterrupted wire, meaning that pieces of wire have to be butt spliced, which makes the suspension elastic. Switches also require wire switches.
So, it looks as if that museum has wiring for trolley poles, and that's the reason why they could not use the pantographs.
Pantographs require no obstruction below the middle of the wire, but allow an easy change of the wire (as we have in a tensioned catenary. The wires over switchwork can be simple wires suspended in parallel at the same height for a few meters.
Trolley poles allow for suspensions coming below the wire a few centimeters besides. On the other hand, they require a uninterrupted wire, meaning that pieces of wire have to be butt spliced, which makes the suspension elastic. Switches also require wire switches.
So, it looks as if that museum has wiring for trolley poles, and that's the reason why they could not use the pantographs.
