Templot Club Archive 2007-2020
|
|||
| author | remove search highlighting | ||
|---|---|---|---|
|
posted: 7 Apr 2012 08:44 from: Templot User
click the date to link to this post click member name to view archived images |
Martin With straight switches the heel clearance of 4.5 ins which is ok if your working in P4 or S7 but for other standards is not sufficient. Do you increase the length of the switch to move the heel chair or do you adjust the planning angle? I could not see the answer clearly on Templot probably not got the right settings for what is shown. Thanks Don |
||
|
posted: 7 Apr 2012 09:33 from: Martin Wynne
click the date to link to this post click member name to view archived images |
Hi Don, The straight switches in Templot are derived from Table 7 in BRT3. The 4.5" heel offset dimension occurs at a virtual heel position a little way short of the switch rail end. So the actual offset at the rail end is somewhat more than 4.5". The rule is that there should be a minimum 2" flangeway clearance all along an open switch rail to ensure that wheel backs cannot make contact with it (which can damage stretcher bars and detectors). For 2.75" rail width this means a minimum offset of 4.75" at the rail end. However, this is still not sufficient flangeway for 00, EM, 0-MF, etc. If modellers using those gauges wish to use loose heels they will need to move the actual heel position further along the closure rail. A custom switch can be derived from the straight switches showing the rail joint in a different position, or the template can simply be marked up as required during construction. If the reason for using straight switches is simply to save space in the track plan design, it is easier to adopt the straight switch geometry for the turnout, but actually to build them as flexible switches in the usual way. The heel joint can be represented with dummy fishplates attached to the flexing rail. Templot also includes a range of non-prototypical short switches where the virtual heel position is at the end of the planing, and the turnout curve begins directly from there. These can be used to create even shorter turnouts where space is so critical that no prototype switch will fit. Templot2/TDV also now has an option to create gaunt turnouts without any switch at all. If the gaunt offset is set to zero, these can be used to create the footprint of set-track style model turnouts. regards, Martin. |
||
| Please read this important note about copyright: Unless stated otherwise, all the files submitted to this web site are copyright and the property of the respective contributor. You are welcome to use them for your own personal non-commercial purposes, and in your messages on this web site. If you want to publish any of this material elsewhere or use it commercially, you must first obtain the owner's permission to do so. |