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posted: 21 Aug 2014 07:49 from: Hayfield
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On my recent trip to Bodmin Central I decided to try and get some close ups of some of the switch and crossing chairs. Looking at the platform resell crossover there seemed to be a mixture of different chairs (2 & 3 bolt). These may have been changed during BR days, or just using what can be found now in preservation circles. 982_201348_500000000.jpg 982_201349_180000000.jpg 982_201349_580000000.jpg 982_201350_190000000.jpg |
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posted: 21 Aug 2014 07:53 from: Hayfield
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Sorry I can't seem to edit between photos, nor can I stitch the photos together. Perhaps I should have taken a Panoramic photo In the top photo there is a strange bar between the rails, may be some form of locking mechanism, but why its there ? The second and third photo shows the different plate under the crossing nose chair. Upper check rail has 4 2 bolt check chairs and one 4 bolt, lower check rail chairs 4 bolt chairs. Bottom photo shots sleepers of varying lengths Here is a close up or the bar 982_210308_130000000.jpg |
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posted: 21 Aug 2014 08:46 from: Phil O
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Hi Hayfield There is a probability that the original check chairs cracked due to excessive forces or bad casting and were replaced with what was available. The plate under the nose is the GW standard Slab and Bracket. see this link and scroll down to see a slab and bracket on the ESR. topic 184 Finally the bar is a an adjustable tie bar used to stop rails spreading out of gauge, usually used where the chairs are a bit loose on the sleeper or timber. For a while one of the platform roads at Paddington was alternate tie bars and acrow props to hold the rails to gauge as the baulk timbering was well past it's sell by date. HTH Phil |
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posted: 21 Aug 2014 09:04 from: Hayfield
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Phil Thanks for the link, but the slab under the bracket looked different to the other one. Just noticed the drain in front of the sleepers which have been cut short in the bottom photo |
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Last edited on 21 Aug 2014 09:05 by Hayfield |
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posted: 21 Aug 2014 09:31 from: Martin Wynne
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Hi John, Thanks for the pics. You had them side by side on one long line which makes editing tricky. I have spaced them out for you. It's always best to press the ENTER key a couple of times (3 times if using Google Chrome) between inserting each picture. They can appear to be on a new line when they are not -- it's just the browser fitting them into the available space. If you do get in a muddle, click the Edit raw button after posting to sort it out. regards, Martin. |
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posted: 21 Aug 2014 10:28 from: Hayfield
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Thanks | ||
posted: 21 Aug 2014 13:39 from: Phil O
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The top photo showing the nose, the nose is sitting on a rectangular slab which has not been shaped back from the nose bolt to the front of each of the other pair of bolt's which hold the brackets. Also note that the timbering is not standard GW practice, which would be square to the C/Line of the turnout. | ||
posted: 28 Feb 2015 11:36 from: D Foster
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The "drain cover" is the top of a catch pit. If you were to look down through the bars you should see a box shaped pit with a half-pipe section across the bottom between two pipe ends. The line of drain usually runs parallel to the rails. There are regular fall patterns and regular frequencies for pits - but the info I have on that is lost at present. However, it's usually very possible to spot lines of catch pit covers along most lengths of track. the most recent ones are very helpfully made of bright blue plastic. It is extremely unwise to tread on the old ones! It hurts a lot if/when they collapse. In fact there are cess pits in both the 6ft and the cess. Given the state of some of the track in the pics this suggests a big water issue here. The track in the first pics is clearly in a very bad state with a lot of infilling contamination of the ballast. this has become so bad that the ballast/mess is beginning to form pillows between the sleepers which have a clear gap between them and the ballast. this means that this track is unstable. it is possible that there are voids under at least some of the sleepers related to this problem. Someone will have the horrible job of digging it all out. ideally the whole track would be lifted out and the ballast "deep dug" down to planet level. Then a modern membrane would be inserted before building up appropriate layers of ballast. Of course, any correction or addition to drains could also be made while the track was out. When track is in this condition it can "pump" vertically. When this is very bad it can produce a derailment. It is terrifying to ride over in a train at speed. In a Running Line track that pumps has a severe speed restriction imposed on it. (There are some nice Youtube examples of Amtrak trains not just pumping but squirting great gouts of water leaving - I think - Chicago). An alternative to pillowing and loose sleepers is that the whole lot sets like concrete. this is more dangerous than loose track - anything hitting it at speed can bounce off. I have know "concrete" ballast to have to be jack-hammered out a chunk at a time. (It broke the back-hoe digger they tried on it). According to my training the sleeper-wide flat plate under the toe of the point blades is called a sole plate. Note that both the sole plate and the gauge tie bar are not continuous between the rails. Both have an insulated joint in them. this is so that they don't mess up any track circuit in the length of track. |
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Last edited on 28 Feb 2015 11:50 by D Foster |
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