• Trams in Czech Republic & Germany

  • Discussion about railroad topics everywhere outside of North America.
Discussion about railroad topics everywhere outside of North America.

Moderators: Komachi, David Benton

  by QuietGuy
 
I just visited the two countries noted and noticed that trams ride the streets and follow the same rules as autos and busses. However, at some intersections, one tram will go straight and another will turn. Is the driver of the tram capable of switching the tracks as he approaches the intersection or is there some timing mechanism that automatically switches the track and the driver waits for the signal to proceede?

  by David Benton
 
I became intimately acquainted with east german tram tracks when the front wheel of my bicycle became jammed in one while touring there . unfortunately despite my close view i did not notice any switching arrangement
i do know that trolley buses here in new zealand choose the route there overhead pickup will take at a intersection by either accelerating or braking at a certain spot , somehow this causes the poles to choose one route or the other .

  by thirdrail
 
The control of light rail or tramway switches is amazingly simple. There is a perfect example of this in several places in the US as well, like Lee Circle in New Orleans, where St. Charles cars in both directions round the circle counterclockwise. There is a contact on the trolley wire overhead. If the motorman has the car under power the switch remains as is. If he is coasting, the switch is thrown. It's that simple.

  by george matthews
 
Originally tramways at complex junctions had a pointsman who directed them. Sometimes the driver had to step down and alter them. Now a tram will have a device inside which changes the points appropriately.

  by David Benton
 
thansk for the explanation , Thirdrail , and welcome toi the worldwide forum .

Do the tracks such as in New Orleans actually having moving points ( or blades you may call them ) ,or is it something on the tramcar itself that moves .
the tram points or switches that i have observed here on heritage tramways didnt appear to have any moving parts , so i presumed it was something on the tram that moved to take the different route . i guess theres more than one system in use worldwide , but i wonder what the norm is .
  by thirdrail
 
David Benton wrote:thansk for the explanation , Thirdrail , and welcome toi the worldwide forum .

Do the tracks such as in New Orleans actually having moving points ( or blades you may call them ) ,or is it something on the tramcar itself that moves .
the tram points or switches that i have observed here on heritage tramways didnt appear to have any moving parts , so i presumed it was something on the tram that moved to take the different route . i guess theres more than one system in use worldwide , but i wonder what the norm is .
Generally streetcar or tram switchwork has single point switches. As street rackage generally uses girder rail with a flangeway as part of the rail, a single point on the outside of the curve suffices. When the switch is set straight the point acts as a guard rail to prevent the car from entering the curve. The switch machine that throws the point is below street level beside the straight stock rail and usially covered with a cast iron lid.

  by QuietGuy
 
"Originally tramways at complex junctions had a pointsman who directed them. Sometimes the driver had to step down and alter them. Now a tram will have a device inside which changes the points appropriately. "

I would like to know what the "device" that is used.

Does the driver have a lever that he push down at the right point in the track to make the switch?

Is there a proximity switch that senses the conductor over head which is in a control circuit with a relay that also senses whether the conductor is drawing power, and if so makes the switch and if not, leave as is as one previous post suggests?

Or do the switches automatically cycle periodically, and the tram waits for the signal to indicate that it has switched to the direction it needs to take (I was able to see the tram signals, but was unable to stand long enough to see several cycles)?

I noticed that the switch mechanizms were just below street level, with large metal covers to access them. These streets also had auto traffic simultaneous with the trams. This would never work in the USA now, too many cars would demand the right of way and be crushed by the trams, as has begun to happen in Houston.

  by DutchRailnut
 
As noted in second or third post, most trams switch the switch by either drawing power or coasting by a set of auxiliary contact wires next to trolley wire. if drawing power while going by the contacts the motors go into dynamic brake for a moment and feed back power for switch trow.
when coasting nothing happens and switch stays same.

  by BenH
 
In Frankfurt am Main (where I've lived for the past 6 years) the points are controlled automatically with some sort of signal that is sent from the tram to the next set of points. I'm not sure how this is done, but I have observed that the driver is not [normally] required to take any action to allign the next set of points on his route.

Every now and then this system seems to fail. In this case the driver must stop, get out of the tram, and use a special metal rod to manually allign the points. The metal rod, which is about 1 meter long, hangs in the cab of all trams (in Frankfurt).

  by Horst
 
Hi,

I've just popped into this topic accidentely, perhaps I can contribute a bit to that questions concerning the switches. I live in Essen, Germany, 40 miles north of Cologne.
German tramway are sort of "standardized" as the same signals are used, the same rules and regulations.
The way that described by DurchRailnut and thirdrail was used up to the seventies. Nowadays things are much more technified (or better, computerized): each tramcar must have (and has) a transmitter which continuously transmitts data about the car, the route, delays etc.
It is necessary because if the tramcar enters either an underground section or a "high-speed area" (faster than 35 mhp, up to 60 mph, which in fact is high speed for a tram car) then the signal system has to know how to handle this car.
Side effect is that the route information can be used for setting the switches. In the approach area of each automatic switch there is a antenna (between the rails, under the surface) which receives the route signal. So the switch "knows" where the tram wants to go to.
If this procedure fails the engineer has two ways to get around.
1. There are switchbuttons in the cab. Appoaching the switch and pressing the needed button will set the switch semi-automatically.
2. The full-manual work. As mentioned each tramcar has a switch lever ("switch iron"). For obvious reasons a tramway switch cannot have a classical lever like railways. The mechanism is under the surface. There is a hole in the surface; through that hole you can reach the mechanism.
German tram engineers like that procedure, especially in ice, rain and snow ;-)
I hope that was not too much. If you have further questions just drop a mail. If you are desperately in need of visual information I could send a low res mpg file as attachment.

Horst
Last edited by Horst on Tue Aug 30, 2005 5:08 pm, edited 2 times in total.

  by David Benton
 
Welcome to the worldwide forum Horst . Please feel free to post as much information as you like , it will be good to have a German participant .
Regarding photos , it is preferable to post links if possible , if not low mb photos are ok .

  by Horst
 
Thank you.

If I had webspace I would have posted the link....
Let's see, actually I have some webspace somewhere, but haven't activated so far.

see you

Horst

  by Komachi
 
Yes, Horst, let me also, belatedly, welcome you to the Worldwide forum. And I'll repeat David's gratitude for a German representative here. I (and hopefully the other participants) look forward to your future posts.

Again, welcome, and enjoy your stay.

  by Thomas I
 
In the City of Bremen exist a tram-junction wich has a signal tower.
(at Domsheide if somebody knews Bremen...).

  by george matthews
 
QuietGuy wrote:"Originally tramways at complex junctions had a pointsman who directed them. Sometimes the driver had to step down and alter them. Now a tram will have a device inside which changes the points appropriately. "

I would like to know what the "device" that is used.

Does the driver have a lever that he push down at the right point in the track to make the switch?

Is there a proximity switch that senses the conductor over head which is in a control circuit with a relay that also senses whether the conductor is drawing power, and if so makes the switch and if not, leave as is as one previous post suggests?

Or do the switches automatically cycle periodically, and the tram waits for the signal to indicate that it has switched to the direction it needs to take (I was able to see the tram signals, but was unable to stand long enough to see several cycles)?

I noticed that the switch mechanizms were just below street level, with large metal covers to access them. These streets also had auto traffic simultaneous with the trams. This would never work in the USA now, too many cars would demand the right of way and be crushed by the trams, as has begun to happen in Houston.
I am sure that in modern systems it is electronic. What it was earlier I don't know.