Templot Club Archive 2007-2020
|
|||
| author | remove search highlighting | ||
|---|---|---|---|
|
posted: 23 Mar 2011 19:21 from: Martin Wynne
click the date to link to this post click member name to view archived images |
http://www.railpictures.net/viewphoto.php?id=240339 |
||
|
posted: 23 Mar 2011 19:57 from: JFS
click the date to link to this post click member name to view archived images |
I like the "point indicators" I can just imagine a driver coming on the junction at 185 mph and thinking, "heck, I going the wrong way!" or what if the one at the switch and the one at the crossing are pointing different ways!!! Ballasting could be tidier... Thanks for the pic, Howard. |
||
|
posted: 23 Mar 2011 21:19 from: Martin Wynne
click the date to link to this post click member name to view archived images |
Here's a nice detail pic of a swing-nose crossing: http://en.wikipedia.org/wiki/File:Bewegliches_Herzstueck.jpg Notice the absence of check rails. Martin. |
||
|
posted: 24 Mar 2011 11:31 from: BeamEnds click the date to link to this post click member name to view archived images |
Martin Wynne wrote: http://www.railpictures.net/viewphoto.php?id=240339That should keep a modeler busy for the winter! |
||
|
posted: 24 Mar 2011 12:44 from: adj click the date to link to this post click member name to view archived images |
Martin Wynne wrote:Here's a nice detail pic of a swing-nose crossing: All very nice and interesting. I remember seeing switching noses in Germany, think it was early 80's. Why is there a need for a moveable nose? Is it due to the length of the nose? I thought the wheels were supported throughout the crossover. Adriano |
||
|
posted: 24 Mar 2011 13:26 from: Martin Wynne
click the date to link to this post click member name to view archived images |
adj wrote:All very nice and interesting. I remember seeing switching noses in Germany, think it was early 80's. Why is there a need for a moveable nose? Is it due to the length of the nose? I thought the wheels were supported throughout the crossover.Hi Adriano, Wheels are fully supported through crossings at any angle, but safe operation of a conventional crossing to prevent mis-tracking to the wrong side of the nose depends entirely on the check rail. The very flat angles of high-speed crossings have a greater risk of mis-tracking, and at high speeds the check rail and wheel backs suffer high intermittent shock loadings which is a bit alarming for such safety-critical components. By swinging the nose there is no break in the rail and hence no need for check rails*. This results in a smoother ride and less wear and tear of the crossing components, but at the expense of maintenance of moving parts, drive motors, detection interlocks, and all the rest. No, Templot doesn't support swing-nose crossings, although geometrically there is no difference from conventional crossings, so you could use the ordinary templates. I've never seen a swing-nose crossing properly modelled -- anyone? I don't mean the old tinplate toy track.  *But the crossing in the first link above does seem to have check rails. I'm a bit puzzled by that. Anyone? regards, Martin. |
||
|
posted: 25 Mar 2011 12:53 from: Judi R
click the date to link to this post click member name to view archived images |
Martin Wynne wrote: Wheels are fully supported through crossings at any angle, but ... check rail.As with most things in life, the full reason is a little more complicated. Yes, the wheels are fully supported and guided but there is a dip. The wheel treads are coned at 1 in 20 and, when the wing rail starts to turn away from the gauge line, the wheel contact point moves outwards. Due to the coning, the running diameter is smaller and the wheel will start to drop ... not a lot, but enough to be significant. The next thing that happens is that the crossing V nose is reached and makes contact with the wheel tread at the proper position but about 2mm lower than normal rail level. This is why the nose is always tapered down by 3mm (1/8 inch in old money). The wheel now starts to ride on the V which is ramped back up to the normal level. This dip causes quite a significant impact at higher speeds and that causes wear to the nose and wing rails. For very high speeds, 100mph and over, swing nose crossings can be used to eliminate the gap and the dip and all the wear that goes with that. Regards, Judi |
||
| 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. |