home - colophon - about ngn -

Neat, simple solution to a problem that has disappeared - how to turn a trolley-pole without sending the conductor out into the middle of the road. Hats off, gentles, to an anonymous but ingenious engineer from the Bristol Corporation Tramways.


Most trams collect their current from an overhead cable, and in the hey-day of the British tram most systems used trolley-poles. A tram pulls the trolley-pole along behind it, like a child going for a walk with a balloon. At the end of the route, someone (usually) had to turn the trolley-pole; the tram, being in most systems double-ended, just set off in the reverse direction. Some extravagant operators simply fitted two trolley-poles, or installed turning loops; others, not necessarily extravagant, went for bow-collectors of one or other design. In general, though, turning the trolley-pole was part of the conductor's duties. Even before the explosive growth of motor-traffic that coincided with the end of the tramway era, walking backwards into the middle of the road, tugging against an heavy spring and squinting against the sky to find something less than an inch wide might not always have been the high-point of a long working day.


Two extra lengths of cable and a couple of spring points, that's all. Just before the end of the overhead, the trolley slips through spring-loaded points at A and B. As the motorman carefully reverses, spring-point B guides the trolley out, away from the tram and into the triangle. The trolley runs up to the apex, down the second side of the triangle – because of its general tendency to follow the tram to which it is attached – and back through spring-point A. Bob's your uncle. "Ease and elegance," to use approving terms from a different domain altogether.