Templot Club Archive 2007-2020
|
|||
| author | remove search highlighting | ||
|---|---|---|---|
|
posted: 20 Mar 2014 11:34 from: Ian T
click the date to link to this post click member name to view archived images |
Hi, Apologies if this is a silly question. I have been reviewing my plans for my layout and I noticed a potential anomaly. I understand the need for the tip of the Vee to have a precise location in relation to the timber it sits on and to my non-railway eye I would have expected a similar relationship to exist at the point where the two wing rails are at their closest (at the bend). All the turnouts I have used (B6 to D9) have this relationship ie the bend is on the centre line of the timber. but all my crossings don't come close, some of them it isn't on the timber at all some it is at the edge of the timber. See attachment. As I say this may not be a problem but it has potential implications for my construction methods (Soldering up a common crossing in a similar fashion to the products sold by C&L, plastic chairs on plastic sleepers). So my basic question is: do I leave it as is or should I shove timbers to put the support where I think it should be? Ian |
||
| Attachment: attach_1785_2426_Turnout_v_crossing.jpg 418 | |||
|
posted: 20 Mar 2014 12:30 from: Martin Wynne
click the date to link to this post click member name to view archived images |
Hi Ian, There is no fixed relationship between the position of the knuckle bend in the wing rails, and the centre of a timber. The distance from the nose of the vee to the knuckle bend varies with the crossing angle (and in models also with the width of the flangeways). Whereas for REA crossings the timbers are at fixed 30" centres (and similar dimensions for most other prototypes). This means that the knuckle bend is usually between the timbers, rather than supported on a timber. It is important to maintain the correct timber spacings at crossings, otherwise the special crossing chairs will not fit and support the rails in the proper place. Phil O of this parish posted some useful close-up pics of crossings in this topic: topic 475 and Michael Davies uploaded many track pics in the gallery at: http://85a.co.uk/forum/gallery_view.php?user=1679#gallery_top Here is a selection of them, all showing that the knuckle bend usually comes between the timbers: 2_200703_340000000.jpg  1679_261346_230000004.jpg  1679_261331_320000002.jpg  1679_261331_240000001.jpg  On this pic below from Mick Nicholson I added yellow lines to show the relationship to the gauge-faces, the blunt nose on the vee, and the way the vee top is taken down below the level of the wing rails to allow for the coning angle on the wheels. In this pic the knuckle bend is closer to the timber than in the above pics because the crossing angle is flatter: 2_270449_340000000.jpg  Many thanks to those members mentioned for uploading these.  regards, Martin. |
||
|
posted: 20 Mar 2014 17:01 from: Ian T
click the date to link to this post click member name to view archived images |
Thanks Martin, I now understand. I am about to start building my first crossing and I didn't want to start off on the wrong foot but you have cleared up my misunderstanding. regards, Ian |
||
| 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. |