Sunday, September 19, 2010

Turning trams: the triangle

The easiest way to turn uni-directional trams on a layout, of course, would be the turning/balloon loop. Just the polarity of the track would be a factor to consider. And if the tram line happens to be double track, even that wouldn't be a problem. The only drawback is that balloon loops are quite space consuming, epecially when not the smallest curve radii are used.

I have been looking for alternatives for the balloon, which there aren't a lot, but found the turning triangle quite useful, and also very easy to construct using the Tomix line of track:
The left design is basically a main line with a facility to reverse into and head back the other way. Several tram systems use these for backup turning options in case of a blockage further down the line. Note the use of an S99 piece at the end, which limits the length of trams. Of course any longer straight piece of track could be used here. (making the triangle considerably less compact though...)

The other option is the use of a turning triangle at the end of a (single track) line. See this video for a tram that uses exactly such a turning facility. By the way, I love the traffic lady and her little shelter in the video :)

This drawing shows a possible double-track solution. Left a balloon loop, using Tomix components (140mm radius minimum).
A turning triangle does require some action from the operator, but makes a great scene for spectators!


  1. My earliest memories of streetcars are of waiting for a (San Francisco Muni) J Church car at the end of the line, at Church & 30th. This was a double track line ending at a T intersection with a symmetrical wye (it's more complicated now because the line has been extended).

    In PCC days, the motorman would go to the "secret" backup controller under a rear seat, and back-pole through the wye. Indeed, it was interesting for the spectator (me!).

    There were a couple of "short turn" wyes, like your upper left example, around the system. There's till a few left.

  2. Those sound like good memories :) I believe there is only one 'wye terminal' in the Netherlands, Holysingel in Vlaardingen. Must have a look there sometime..

  3. Just realized that the balloon loop isn't such a good design because the rather tight S-curve in it. There are some good designs on this site: