While I was watching several videos on YouTube of Toronto streetcar routes taken from the driver's view out of the front winshield, I noticed several signs in the overhead wiring. These looked to be blue with white lettering reading "NA". Can anyone explain their meaning?
Were they located just before facing-point switches?
Yes
Facing Point Switches that were active were controlled by a sensor in advance of the switch that was controled by a "Power ON/OFF" sensor. I suspect that the sign you saw was to indicate the switch you saw had been made manual and the sign indicates Not Active. But I would hope someone more knowlegeable would confirm my supposition. Can you post the link to the video you saw so I can see it.
Is it this?
That's it.
Found this
"To say the least. There are more out of service electronic switches than serviceable ones at the moment. Whenever you see one of those green signs hanging from the streetcar wires that says "NA" with an arrow pointing in a certain direction - that's an electronic switch. NA means "Necessary Action" - which means the operator has to press a button if they want to go in the direction of the arrow. There is a coil onboard the streetcar that broadcasts a low frequency signal which is picked up by a loop in the switch and voila, the switch actuates. Most of these green signs are currently covered with yellow ones that say the switch is out of service and must be used manually."
Normally when the car changes the route, the driver uses the switch iron to move the points. It takes a bit of muscle to do that. When there is a diversion, say the Westbound Queen car went down to King at Church and is going back to Queen at Bathurst, there will be a guy sitting there with the iron so the driver doesn't have to get out and do it. But sometimes the remote control will actually work but that is rare.
I recall in 1964 riding a PCC in Pittsburgh quite near the PRR station. The switches there were controlled by a toggle on the motorman's dashboard; no getting out with a switch iron. I was given to understand these were common there, at least downtown.
I especially enjoyed watching the motorman operate these switches in wet weather, because with a flick of his wrist from inside, the switch movement forced a small jet of water straight up, startling unsuspecting pedestrians nearby!
At one time, they used a short section where the motorman had to either coast through an area or have power on through the section which would determine the switch operation. I believe it was sensitive to the amount of power (amperage) that the car drew as to whether it actuated or not. Car lights, heat and air compressor were not enough to trigger but motor power was. This was also used on some trolley bus overhead switches
The two systems described above are identlcal. The Toronto Peter-Witt cars did not have the switch and use power-on, power-off. The Pittsburgh Peter-Witts akso did not have the switch. Ditto Brooklyn.
For the power-on - powser-off system to work safely, the operator must have the ability to both power the motors and brake at the same time. The PCC basic control system prevents this, since motors are in dynamic-brake-mode whenever brakes are applied. Thus the PCC cars have the "action" switch to run current through a resistor, replacing the motor current.
The Thord Avenue and the Omaha and Coucil Bluffs systems did not employ any electric track switches, since the combination "dead-man's" pedal - lift-foot-to-brake - lift-foot-to-oprn-door control also does not permit simultaneous braking and powering. And the PCC-equiped action swtch and bypass resistor is lacking. Important junctions did have switch tenders. On Third Avenue, at 42nd Street & 7th Avenue (Times Squre). West Farms Square, 181st & Broadway, and Gettys Square, Yonkers, a switchman's shack included a large lever with a mechanical connection to a switch-point. In Yonkers, two levers.
Electroliner 1935 At one time, they used a short section where the motorman had to either coast through an area or have power on through the section which would determine the switch operation. I believe it was sensitive to the amount of power (amperage) that the car drew as to whether it actuated or not. Car lights, heat and air compressor were not enough to trigger but motor power was. This was also used on some trolley bus overhead switches
As far as I know, this method is still used in New Orleans. I remember seeing the motorman rapidly sweeping the throttle back and forth while the car coasted slowly through a curve where there were switches.
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"A stranger's just a friend you ain't met yet." --- Dave Gardner
Thanks to all who responded to my question. I recently heard from a friend who lives in the Toronto area who's neighbor works for the TTC, and who explained why the "NA" turnout control system is not being maintained. The new Flexity streetcars use a new wireless control ystem; the "NA" signs are being removed during routine overhead wire maintenance.
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