Templot Club Archive 2007-2020
|
|||
| author | remove search highlighting | ||
|---|---|---|---|
|
posted: 14 Jan 2009 16:00 from: Jim Guthrie
click the date to link to this post click member name to view archived images |
I've been messing about with a design for a layout based on the Caledonian in pre-Grouping times (mentioned in Scott's "Spare Room" thread). The basic shape will be an ellipse and the radii will be quite tight, so to keep the radii of crossover roads between double track to an acceptable minimum, it will be necessary to use crossing angles in the 1:9+ range. In one crossing, there could be a single slip and that should have a switched diamond with an angle of 1:9 through the K crossings. Did pre-Grouping companies use switched diamonds - which could also be interlaced? I've only been aware of switched diamonds appearing from the Grouping period onwards. Jim. |
||
|
posted: 14 Jan 2009 16:50 from: Martin Wynne
click the date to link to this post click member name to view archived images |
Jim Guthrie wrote: Did pre-Grouping companies use switched diamonds - which could also be interlaced? I've only been aware of switched diamonds appearing from the Grouping period onwards.Hi Jim, The answer seems to be yes, but probably not widely used. C. J. Allen (1915) shows at Fig. 119 -- "Messrs. Sykes and Howard's Patent Movable Diamond Crossing". He says one such had been "recently laid by the LBSCR at the new Victoria station". There is an alternative idea at Fig. 117 -- "Messrs Henry Williams' Patent Diamond Crossing Point Protector" in which a component is raised vertically into the flangeway gap at the K-crossing, to prevent wheel flanges striking, or going the wrong side of, the point rails. That would make an interesting model! I will scan these later, but I'm a bit pushed for time now. However, C.J.A. also lists dimensions for GER fixed K-crossings, which go up to 1:9. So you may get away with a fixed crossing in the slip if you can get it to run reliably. regards, Martin. |
||
|
posted: 14 Jan 2009 18:10 from: Jim Guthrie
click the date to link to this post click member name to view archived images |
Martin Wynne wrote: Hi Jim,Martin, Many thanks for that. If 1915 was an approximate date of introduction then it's possible that such installations were only on new, complex installations and I don't think my proposed layout could be considered as such :-) Unfortunately, the slip will be in a fairly critical situation as part of a trailing crossover with the straight road of the slip being the lead into the goods yard. So a typical operation would be reversing wagons across it - probably the ideal situation for vehicles to take the wrong road.  I dare say I could use the trick of raising the check rails at the "K" crossings to extend the checking effect of these rails to prevent wrong road diversions as far as possible.Jim. |
||
|
posted: 14 Jan 2009 22:03 from: Martin Wynne
click the date to link to this post click member name to view archived images |
Jim Guthrie wrote:If 1915 was an approximate date of introduction then it's possible that such installations were only on new, complex installations and I don't think my proposed layout could be considered as suchHi Jim, Mick Nicholson has prompted me to look at the NER 1912 track standards book, which I should have done in the first place of course! Page 51 has a detailed drawing of a switch diamond, for angles 1:8.1/2 to 1:12 in 1/2 steps. However, it's timbered rather than sleepered. I will get it scanned shortly. Thanks Mick. p.s. C. J. Allen's 1915 book was a reprint of articles which had appeared earlier. 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. |