Single moving points do seem to be a common feature of many tram systems. I’ll just mention as well, since no one seems to have done so as yet, that many of these may be spring switches, which are common wherever a single-track line diverges to a loop or pair of runaround tracks at the line’s terminus. When a more or less standard traffic pattern exists, the use of spring switches is a simpler solution than remotely-controlling the switches, and in most instances eliminates requiring the tram operater to line the switches manually.
In such an arrangement, the movable point is permanently lined for one route, but a strong spring rather than the usual rigid linkage holds it in position. When the tram enters the switch from the ‘normal’, or facing direction, it follows the route for which the moveable point is set. A car entering the switch from the opposite direction, OTOH, will either push the point into the correct alignment or push it aside, depending on which route it used to enter the switch, with the point returning to its normal position when the car has passed.
I’m pretty sure I’ve seen narrow-gauge systems in continental Europe which have a full two-blade arrangement. And where it’s essentially a light-rail system with street running (Calgary, Manchester, from Google I see San Jose is like this, etc.), regular points/switches are used.
The actual steering mechanism for a streetcar is the flanged wheel and rail, just like a train. They use switches to change tracks, just like trains.
As far as throwing the switches, there are several mechanisms. The simplest is the crowbar method. There are manual switch mechanisms also, which are buried in the pavement and accesses through a heavy steel plate door. Then there are several automatic mechanisms, controlled by a dispatcher or my a radio broadcast tone.
[QUOTE=BlakeTyner]
In this photo you can see a transit employee manually switching tracks for a streetcar at a turnout. It looks like he carries his own tool to do this, as opposed to a regular switch that would have a linkage permanently attached. I’m guessing it’s a fairly simple matter of moving each point with the tool, much like a crowbar.
http://www.trainweather.com/FirstDayPowerClintonExt011807-chgswitch-5R.jpg
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Looking at the photo more closely, it appears that the driver’s “crowbar” is not the normal mode of operation for this switch. If you look between the driver’s legs, you’ll see a long steel plate lying perpendicular to the rails. This is an access cover that conceals the mechanism for moving the switch point. I’d guess it’s a solenoid.
[QUOTE=zagloba]
Looking at the photo more closely, it appears that the driver’s “crowbar” is not the normal mode of operation for this switch. If you look between the driver’s legs, you’ll see a long steel plate lying perpendicular to the rails. This is an access cover that conceals the mechanism for moving the switch point. I’d guess it’s a solenoid.
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For single point switches, it’s a spring mechanism that serves to hold the point in whatever position the crowbar pries it into.
[QUOTE=TheLoadedDog]
It’s a fantastic spark show if it happens at night too. I was quite sad when Melbourne replaced the trolley poles with pantographs.
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I once saw an electric bus (the term “trackless trolley” just doesn’t sound right to me) pass another bus that was on the same pair of wires. Hilarity ensued.
[QUOTE=David Simmons]
Ya know, people have wound up in Gitmo for less.
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Aw, gee, don’t you think that’s overreacting? Granted, it was a less than Stella joke …
