Interesting response on a mailing list whose subject is the electric trolley bus. Most of the posters are from Vancouver, one of six cities in the USA and Canada with this type of transit vehicle (the others being Seattle, San Francisco, Dayton, Philadelphia and Boston).
Brill was a former manufacturer of trolley buses until the 1950s; in Canada, they were known as Brill/Canadian Car and Foundry and the buses were known as CCF-Brill buses. New Flyer of Winnipeg makes them now; their latest two orders completely reequipped the fleets in Vancouver and Philadelphia, and are being considered for Seattle. Their motto, "Miles Ahead", however, is unfortunate. www.newflyer.com Carleton -----Original Message----- From: Mark W. Walton [mailto:[email protected]] Sent: Tuesday, February 08, 2011 22:15 To: 'etbc' Subject: RE: Are the Brills preferable? I miss them too Thanks for the explanation, Richard. BTW, an acceleration rate of 3.75ft/sec2 translates in modern terms to 1.143 metres/sec2. The Brills were built to Imperial measurements, I don't know about the Flyer E902s; the current New Flyer E40LFR and E60LFR probably to metric specs. Mark Walton [email protected] -----Original Message----- From: Dale Laird [mailto:[email protected]] Sent: Tuesday, February 08, 2011 2:12 PM To: Richard Schauer Cc: Mark W. Walton; 'etbc' Subject: RE: Are the Brills preferable? I miss them too Hi Richard; from what had been written here, I figured your explaination would be too complicated for some people, so I used the word 'governor' because at least it's intent would be familiar. As you said, the acceleration was set at the factory. I always assumed that was the reason the 2400 series were slower because all 16 of them had been built and set as one order. To explain why not all Brils were the same, because I knopw someone will ask: The purchaser can order a specific acceleration rate. Some transit operators feared passengers would fall down and some believed their passengers had the grip of King Kong on the stancheon. MIT determined the comfortable accel rate for a standing pass. is 3.75ft/sec2 On Tue, 8 Feb 2011, Richard Schauer wrote: > On Mon, 7 Feb 2011, Dale Laird wrote: > >> All trolleys (bus and streetcar) with foot pedal control had governors. >> They are called "automatic feed". Try thinking about what would happen if >> the operator could put the pedal to the floor and instantly apply the full >> 600 volts to the motor(s). >> >> On Mon, 7 Feb 2011, Mark W. Walton wrote: >> >>> Yes, I have. Governors can probably be tuned for different weights and/or >>> HP ratings. Did any of the Brill trolleys have governors? > > I realize that electrical things run on magic smoke and so there's no need > for accuracy in nomenclature or descriptions of how they operate :-), but gee > whiz guys. You won't find anything like an engine governor with springs and > centrifugal weights on a trolleybus or streetcar. The brains of automatic > acceleration in the days of the Brills was something called an accelerating > relay (for GE) or a limit relay (for Westinghouse). It told the controller > or control group what to do. > > Without traction motor current, it sat in the "keep notching up" position. > Electromagnetism from passing current pulled against the spring that held it > in that position, until the coach notched up "one too far" and the relay > moved to the "hold it right there" position. As the speed of the coach > increased, current fell until the relay gradually moved back into "notch up". > > If you wanted a faster acceleration for the same weight coach, you made the > spring stronger, or you made the magnetism weaker (for example, by shunting > some of the current through another path, or by reducing the number of coil > turns on the electromagnet). This permitted more current to flow before the > relay moved. If you have a heavier coach, to get the same acceleration as a > lighter one, you'll need more current too. These adjustments were made at > the car builder, and again after overhauls or when it was suspected that the > setting had changed. > > Yes, it's simplified. I'm ignoring lift coils, rate coils, backspotting > contacts and circuits, and a bunch of other things. But the above > description is the "meat" of how it works. > > Richard Schauer > Illinois Railway Museum, Trolley Bus Dept. volunteer > >
