Many the stories that happened on the North Shore Line with drunken sailors… Relieving themselves in 3rd rail territory. There’s one to tell the grandkids, if in fact you are able to have any ,after an encounter with 600 volts on a very sensitive body part .
Randy
Chicago Aurora and Elgin trains on their Geneva-St. Charles line switched between third rail and trolley pole three times in the course of a one-way trip. Outbound from Chicago (and onto the branch) on third rail, then to trolley wire through the streets of West Chicago, then back to third rail in the open country and finally back onto trolley wire in Geneva and St. Charles. The conductor really got a work out on those trips!
Thanks, Dutch, it has been a while since i’ve been down that way. Did they also change to commercial 60 cycle power when the change in voltage occurred? I can’t figure how the older M.U.s and FL9s,that weren’t rebuilt “survived” the voltage change, but their electrical systems must have some flexability in them to allow for voltage variations.
The third rail is DC powered so no cycles other than on feed side of substation. but that was always 60 Hz as far as I know
The info about the four rail London System is interesting - I always thought it was to keep electrolysis corrosion out of the metal tunnel lining. As for signalling - is it a “single rail” or “double rail” system, or a “frequency track” ? And does it require impedance bonds at insulated joints?
On the “Mythbusters” TV show the simulated urinating on a 3rd rail to test the proposition that one would be shocked - they found the stream broke up on the way down and broke continuity… but then a couple of six-packs before trying it for yourself might give a different result.
The FL9s would have preferred even higher voltage DC. Control system had to employee several stages of traction motor field shunting in order to get locomotive to operate at full speed while on 600 VDC 3rd rail.
Somewhat higher voltage on the MUs should have made little difference. The control system on them works by putting a variable resistance between the 3rd rail and the traction motors. Somewhat higher voltage would just change the balance speed for each step of resistance.
The Fl9 control system for Third rail works same, A relay panel over compressor handles several dynamic grid resistors in series between the third rail and traction motors, the field shunting system for diesel and third rail is same and is a two stage Field reduction, at 45 and 60 mph.
It may be that part of the reason is avoidance of electrolytic corrosion (or was originally).
As far as I know, generally the signalling on the ‘Tube’ is two aspect colour light stop and repeater (distant) signals with automatic train stops, controlled via conventional double rail track circuits. There are probably other types of track circuit in use on the system as well - the oldest parts of the system are over 140 years old so there has been a lot of evolution. The newer lines can be different - the Victoria line has had automatic train operation since it opened in 1967 (using multi-frequency control currents in the running rails), and the recent Jubilee line extension was originally going to be ultra-modern moving block signalling - but time and cost pressures resulted in it being equiped with fixed-block in the end.
Tony
There has been a feirly comprehensive set of responses to this subject.
There is also side-contact 3rd rail. One or two tunnel lines have had rail on the roof of the tunnel and a simple circular line in the UK had the collection from the wall opposite the platforms!
Some tram systems have used studs that rise as the vehicl approached and went down into the road again after - but they often stuck in the raised position, which caused problems for haorses. I believe the Bordeaux (France) system uses a modern and more reliable version of this.
Some systems, like washington, had the rail in a conduit, hopefully secure from accidents!
What about Monorails?
I seem to recall watching “Mythbusters” on my cable TV channel and they appeared to prove thaat it was virtually impossible to be electrocuted by peeing on the 3rd rail unless you happened to be kneeling by the 3rd rail and doing the business a few inches away from the rail…
Seen same epsisode
Maybe one for the urban myth’s thread, but apparently relieving oneself on the third rail and allowing the current to arc back was, if you survived the experience, a cure for gonhorrea practiced by many Allied Servicemen in Berlin post 1945.