Quote:
Originally Posted by kingsway john
When running on the overhead wire, the trams used an earth return via the wheels and rails. (in fact in event of a derailment where the trolley pole still beon the wire, the crew were instructed to jump from car to the ground rather than create an earth when dismounting!).
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Ok, I jump in here to answer a few days after the last post
But as you say the return is through wheels to the rail.
When I was active on the museum/vintage/commercial tram traffic with old trams we learned exactly what you said. Jump of without touching the tram and then pull down the pantograph (or pull it down from inside the tram if possible) with the wire. Then mount the "växelspett" (metal bar with narrow end and a handle used for turning the point to change track) to the coupling and to the rail. Then pull up the panthograph again and drive off from what isolates the tram.
Of course, if you have derailed you don't need to drive away from there. Let the recovery crew take care of that.
But two axle trams (not bogies) can be isolated if there is a lot of sand or other isolating material on the rails.