On 20/04/17 15:05, 'Noel Reed'noelreed10@... [TramsDownUnder] wrote: >
> /The trams will be double ended [bi directional] so brushes would be
> in front of and behind the pick-up shoes. Would the ‘rear’ brush
> contacting a power rail still ‘alive’ cause a CB or fuse to cut power
> ? How would wear of the brushes be monitored so that they always
> contact the rail. Would they retract to avoid wear on the road surface
> and on ballasted track when the tram reaches the proper overhead
> trolley wire and *_be proved_*_to have re-lowered_ when returning to
> the APS sections on the return journey ?/
I couldn't say anything about 'proved', but watching the console of a tram in Bordeaux while transitioning, there are appropriate 'animated' graphics that depict the raising or lowering of the APS shoes, and it just doesn't flip from deployed to retracted or vis, it sits there for 20 seconds or so doing a little animation of raising or lowering. And the indicator lamps in the control switches blink while it's transitioning too.
Now it could be just playing a little movie file for the time the mechanism is supposed to take, or it could be playing the movie in a loop till it gets feedback that the shoe is in position. Can't say. But the console indication definitely wasn't binary (up or down).