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posted: 19 Apr 2018 16:13 from: richard_t
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Hi A recent photograph on ebay showed that on my chosen prototype where a road went under the station the track was on way-beams. I know little about way-beams, so I wonder if I could ask the following: (These are for bullhead rail) What would the longest beam be, and if the section of track was longer, would the joints in the way-beams be staggered. The track is straight in all cases in my chosen prototype where it's on way-beams. Would any rail joints be on the beams? I've seen on the MOD document that rail joints shouldn't be within 4m of the end of the way-beams. It seems there are cross beams (for want of a better term), between the way-beams every 4 or 5 chairs. Does this seem right and was there a fixed size for the beams? Finally, on one of the platform roads where the under bridge goes under there's a couple of turnouts. I don't have photographs of this area, but I'm guessing these wouldn't be on way-beams? When the station was relaid with flat bottom rail, I think the way-beams where all removed, but I think I'd like to keep them, as it would add a little interest. Thanks in advance Richard |
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posted: 19 Apr 2018 18:35 from: Phil O
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I am unable to have a look on Google Earth,to check, but most if not all the railway bridges over the Thames in London were on way beams. Phil. |
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Last edited on 19 Apr 2018 18:36 by Phil O |
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posted: 20 Apr 2018 14:34 from: Judi R
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Longitudinal timbers are used where vertical clearances are tight because they save the depth (and weight) of the ballast. They are directly fastened to the steel bridge beams so it's difficult to adjust alignment and are usually tolerated only where necessary in slow speed areas. Yes, I know there are high-speed exceptions. The long timbers are usually 12" x 12" and sometimes bigger, up to 18" x 18", and the cross timbers - the transoms - are usually around 6" x 6" and are paired with a steel tie rod to strap the whole lot tight to hold the gauge. Judi R |
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Last edited on 20 Apr 2018 14:35 by Judi R |
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posted: 4 May 2018 10:44 from: richard_t
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Thanks Judi that was a great help. I've found a bit of further information in the NERA "Standard Railway Equipment, Permanent Way, 1926" booklet, diagram 107. It has three arrangements, S1J chairs on 18" beams, L1CC chairs on 18" beams, and M1 chairs on 12" beams. For 60' rails, these chairs are all placed at 2' centres. Looking at the picture it seems to be M1 chairs, as there's no checkrail visible, and M1/L1 are distinct enough from S1J chairs. On diagram 107 there are two "chairings", with the 2nd chairing showing the use of a saddle chair (either S1 for S1J/L1CC arrangement, or M1 for the M1 arrangement) under the fishplate. This looks most interesting, so I knocked up these renders. 499_040542_180000000.png 499_040543_250000000.png |
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posted: 4 May 2018 17:13 from: Andrew Barrowman
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So that's why they are called bridge chairs! Nice 3D model. Are you going to have it printed? Cheers! Andy |
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posted: 5 May 2018 10:33 from: Judi R
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That's a beautiful picture! Only one niggle, I believe the fishplate bolts should be placed with the heads in the 4-foot. Judi |
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posted: 5 May 2018 20:12 from: Rob Manchester
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Judi R wrote: That's a beautiful picture! Only one niggle, I believe the fishplate bolts should be placed with the heads in the 4-foot.Judi, I thought that at first but had a niggle that maybe in this situation there may be reasons for putting the bolts the opposite way to normal. Despite a concentrated look through many books/pictures I haven't found any evidence of this The main conclusion I came to was that I didn't have many pictures of rails on bridges ! Rob |
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posted: 6 May 2018 13:24 from: richard_t
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Judi is correct - I blame my summer cold :-( | ||
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