Nick G Posted November 2, 2015 Share Posted November 2, 2015 I was wondering what is the purpose of these buffers rather than permanent buffers please? Link to post Share on other sites More sharing options...
Titan Posted November 2, 2015 Share Posted November 2, 2015 I think the idea is that they are clamped to the rails, such that in a collision they slide along them using friction to help stop the train rather than a sudden stop. Link to post Share on other sites More sharing options...
Nick G Posted November 2, 2015 Author Share Posted November 2, 2015 I think the idea is that they are clamped to the rails, such that in a collision they slide along them using friction to help stop the train rather than a sudden stop. Right, thank you, makes sense I suppose but I could see the point in a bay platform or terminus but these are on sidings just used to stable locomotives. Link to post Share on other sites More sharing options...
Titan Posted November 2, 2015 Share Posted November 2, 2015 Might explain why there is not a very long stretch of track beyond the buffers for them to get pushed along. Locomotives are heavy and expensive things, and can do a lot of damage even at slow speed. There may even be a greater risk of a runaway at a loco stabling point - loco not properly secured, brakes leak off... At terminal stations there are often extra clamps behind the buffers so as they get pushed along they collect more clamps and have progressively more friction added to slow the train down, rather than a big shock all at once. Link to post Share on other sites More sharing options...
Vin Posted November 2, 2015 Share Posted November 2, 2015 Hi, They are clamped to the railhead but absorb the energy of a loco, even at slow speed by being pushed along the track. It reduces damage to both the track and vehicle involved. Where as a traditional set of buffer stops were attached to the rail. An impact into them had several dramatic and destructive effects. The most common being the vehicle riding over the top, loosing bogies and underframe equipment in the process. The other was the fishplates infront of the buffers shearing off and the buffer stop being pushed through the dirt and effectively derailing the vehicle hitting them as there was a large gap in the rails. Regards Vin Link to post Share on other sites More sharing options...
Pacific231G Posted November 2, 2015 Share Posted November 2, 2015 I was wondering what is the purpose of these buffers rather than permanent buffers please? They are indeed friction braked buffer stops and they can be just as permanent as more common types. The Rawie name on the side was the clue and this German company makes a range of them as well as fixed buffer stops. Friction buffers not only bring the vehicle to a more gradual stop but they and the track should remain undamaged while doing so. Additional clamps can be bolted to the rail behind the buffer to add extra braking force and this design appears to be their 4 ZEB/6. More on them on the company's website including a data sheet (in English) http://www.rawie.de/index.php/gb/bahntechnik/vollbahn/gueterverkehr/bremsprellboecke If you're interested in modern railways the website is worth exploring. It also includes a gallery of older types of buffers and their failures but best of all in the experiments and tests section is a series of very convincing video clips of their buffers being tested with some quite rapid "runaways" including one in the London Underground Depot at Upminster. What is most incredible though in the earlier clips from the 1990s is just how close to the point of impact a fairly large number of railway staff were standing. In the construction and operation section is a very nice animation to demonstrate the principles of friction buffer stops- though the test clips are also very clear and a longer live action piece showing just one of their staff and a crane driver installing one at their works. Rawie employs about sixty people in Osnabrück and as well as a wide range of buffers and stops for everything from trams to crane tracks also makes lifting access barriers and loading ramps associated with buffers. One type I hadn't seen before were folding buffers that can be swung in or out. Link to post Share on other sites More sharing options...
RMweb Premium BR60103 Posted November 3, 2015 RMweb Premium Share Posted November 3, 2015 Is there another device just to the left of the buffer stop? It looks as if it has had some use -- some paint has been taken off. Link to post Share on other sites More sharing options...
Rivercider Posted November 3, 2015 Share Posted November 3, 2015 Is there another device just to the left of the buffer stop? It looks as if it has had some use -- some paint has been taken off. Is that the tip of a snow plough? cheers Link to post Share on other sites More sharing options...
Vin Posted November 3, 2015 Share Posted November 3, 2015 Hi all, That is the tip of the snowplough that can be found in York. The bufferstops are in the parcel spur infront of the Network Rail building at the back of the station. Regards Vin Link to post Share on other sites More sharing options...
Nick G Posted November 4, 2015 Author Share Posted November 4, 2015 Thanks for all the replies. Link to post Share on other sites More sharing options...
Boris Posted November 5, 2015 Share Posted November 5, 2015 Worth noting as well that in many locations these blocks are also tied into the signalling system. Link to post Share on other sites More sharing options...
Pacific231G Posted November 5, 2015 Share Posted November 5, 2015 Worth noting as well that in many locations these blocks are also tied into the signalling system. Intriguing- I've never heard of of a buffer stop tied into the signalling system- does it protect adjoining tracks if the buffers are moved - or are you referring to the moveable derails and blocks that this company also makes and refers to as "track locks" and "brake shoes" ? Link to post Share on other sites More sharing options...
Boris Posted November 5, 2015 Share Posted November 5, 2015 Intriguing- I've never heard of of a buffer stop tied into the signalling system- does it protect adjoining tracks if the buffers are moved - or are you referring to the moveable derails and blocks that this company also makes and refers to as "track locks" and "brake shoes" ? No, its a discussion I had with some contractors regarding the white line on the example of these in Whitby, the white line being to ascertain whether the buffers had been struck/moved or not, with striking these kind of blocks being treated as a collision. There is apparently some form of sensor supposed to be installed on ones in passenger termini (the proviso being new works after a certain date which I forget) to alert the controlling signaller that the blocks have been struck. Link to post Share on other sites More sharing options...
RMweb Premium Reorte Posted November 5, 2015 RMweb Premium Share Posted November 5, 2015 No, its a discussion I had with some contractors regarding the white line on the example of these in Whitby, the white line being to ascertain whether the buffers had been struck/moved or not, with striking these kind of blocks being treated as a collision. There is apparently some form of sensor supposed to be installed on ones in passenger termini (the proviso being new works after a certain date which I forget) to alert the controlling signaller that the blocks have been struck. Interesting, particularly as it looks like the ones in the picture have had something in contact with them at some time. Link to post Share on other sites More sharing options...
Boris Posted November 5, 2015 Share Posted November 5, 2015 Interesting, particularly as it looks like the ones in the picture have had something in contact with them at some time. Absolutely but its unlikely those blocks have the sensor because of their location Link to post Share on other sites More sharing options...
Nick G Posted February 20, 2016 Author Share Posted February 20, 2016 Model version of these bufferstops almost finished. Link to post Share on other sites More sharing options...
RMweb Premium phil-b259 Posted February 20, 2016 RMweb Premium Share Posted February 20, 2016 Worth noting as well that in many locations these blocks are also tied into the signalling system. Sounds like you are thinking of a "track circuit interrupter". This is a small device fitted to one rail that sheers into two pieces, breaking an internal electrical connection if it gets struck. This is wired in series with the adjacent track circuit (which a derailed loco / pushed back buffers may end up foul of), and ensures that any collision is protected by forcing the relevant signals to red. They are more commonly fitted to trap points than buffers however. Link to post Share on other sites More sharing options...
Boris Posted February 20, 2016 Share Posted February 20, 2016 Sounds like you are thinking of a "track circuit interrupter". This is a small device fitted to one rail that sheers into two pieces, breaking an internal electrical connection if it gets struck. This is wired in series with the adjacent track circuit (which a derailed loco / pushed back buffers may end up foul of), and ensures that any collision is protected by forcing the relevant signals to red. They are more commonly fitted to trap points than buffers however. Nope, I am thinking about the signalling specifications that I have in front of me. Link to post Share on other sites More sharing options...
Jim Martin Posted February 20, 2016 Share Posted February 20, 2016 Are the yellow things in the original photo some sort of wheel chocks with handles so they can be removed from the rail without having to go near the track? Jim Link to post Share on other sites More sharing options...
25901 Posted February 20, 2016 Share Posted February 20, 2016 Yes there are handled wheel chocks kept under there and the buffer/grease marks have been put on there by the DRS drivers who for some reason love buffering up to the buffers Link to post Share on other sites More sharing options...
Fay Singpoint Posted February 22, 2016 Share Posted February 22, 2016 Sounds like you are thinking of a "track circuit interrupter". This is a small device fitted to one rail that sheers into two pieces, breaking an internal electrical connection if it gets struck. This is wired in series with the adjacent track circuit (which a derailed loco / pushed back buffers may end up foul of), and ensures that any collision is protected by forcing the relevant signals to red. They are more commonly fitted to trap points than buffers however. We have been fitting "Track circuit Interrupters" to friction buffer stops for a good many years. Link to post Share on other sites More sharing options...
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