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| Boom gate failures force indefinite shutdown (Melbourne, Aust) 14/04/2015 at 17:42 #71078 | |
GeoffM
6282 posts |
" said:You put up a sign warning road users of the danger of high speed trains (in that case 110mph). Active warning devices should not relieve the road user of their responsibility to be on the lookout for rail traffic...which naturally should have the right of way B) .Maybe I need to add a sarcastic smiley - your tongue must have been firmly in cheek writing that! SimSig Boss Log in to reply |
| Boom gate failures force indefinite shutdown (Melbourne, Aust) 14/04/2015 at 18:32 #71083 | |
Jersey_Mike
250 posts |
" said:Ha, both my driver's education manual and the Boy Scout Railroad merit badge both state that proper level crossing procedure includes slowing your car and looking/listening out for approaching trains even if there are warning devices because said devices can sometimes fail. All crossing protections have something known as "snitch lights" that signal the train crew that the crossing has activated. If they do not see that the crossing has activated they must slow the train and use more To be fair those few 110mph crossings on the Hudson Line are a bit of an anomaly as they were grandfathered in. The Incremental Train Control System signaling overlay now in service on two 110mph routes in the Midwest was originally designed as a grade crossing safety system that would reduce train speed in case of a crossing failure. Log in to reply |
| Boom gate failures force indefinite shutdown (Melbourne, Aust) 14/04/2015 at 18:43 #71085 | |
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GeoffM
6282 posts |
" said:All crossing protections have something known as "snitch lights" that signal the train crew that the crossing has activated. If they do not see that the crossing has activated they must slow the train and use moreIndeed but said lights are rarely visible from more than a few score yards so there's absolutely no hope of slowing if you're doing anything more than about 25mph or are coming around a bend. SimSig Boss Log in to reply |
| Boom gate failures force indefinite shutdown (Melbourne, Aust) 14/04/2015 at 18:59 #71087 | |
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Muzer
718 posts |
In the UK, crossings are also monitored for failures. This is why we have so many different types. Obviously the simplest is CCTV/MCB — the signaller/crossing keeper can see if the barriers aren't down! AHBCs, there is some form of proving (not entirely sure what) to ensure the barriers are down. Does anyone know how this works — is it shown to the signaller if the barriers haven't gone down? Since the strike-in point is often the wrong side of braking distance, how does this work? And AOCLs/ABCLs/AOCL+Bs/etc. work in a similar way to what you describe, where there is a light that the driver must observe before being allowed to pass over the crossing. These are obviously only suitable for places with low line speeds as otherwise having to slow right down is too much of a time waster. Log in to reply |
| Boom gate failures force indefinite shutdown (Melbourne, Aust) 14/04/2015 at 21:31 #71093 | |
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clive
2738 posts |
" said:The SimSig AHB module is basically a simulation of the circuits in the Red Book. The signaller just has the three lights: raised, working, failed. The failed light comes on in a number of situations, some simulated (barriers down too long) and some not (barrier detection failed, local control activated). If I'm recalling correctly, you will get the alarm light if the barriers aren't down within a certain time of the crossing activating. Quote: It doesn't. If the signaller sees the crossing fail, she's supposed to collar the protecting signals on either side, which can be up to 10 minutes running time away IIRC. But if the barriers fail during an operating cycle, the hope is that car drivers will obey the flashing red lights. There's no way to stop a train in time if the crossing operation fails; it's simply viewed as a low enough risk to be acceptable. Log in to reply |
| Boom gate failures force indefinite shutdown (Melbourne, Aust) 15/04/2015 at 11:11 #71109 | |
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Jan
889 posts |
" said:Ha, both my driver's education manual and the Boy Scout Railroad merit badge both state that proper level crossing procedure includes slowing your car and looking/listening out for approaching trains even if there are warning devices because said devices can sometimes fail. While I agree that one should be on the lookout as far as possible at level crossings, in practice this isn't always possible. To give an example from Germany: For level crossings without technical protection, appropriate sighting distances have to be maintained so road users have a realistic chance of spotting an approaching train in time. For level crossings equipped with lights/barriers, there's no such requirement, so at those kinds of level crossings it is often not possible to spot a train approaching at full speed in time. In some of the more extreme cases, by the time you can properly see an approaching train, your bonnet is already parked over the tracks. Especially in urban/built-up areas, increasing sighting distances might involve demolishing a number of buildings, so in the end, as a road user you have to rely on the correct operation of the level crossing equipment, or failing that, the proper implementation of degraded working, i.e. trains are cautioned over the level crossing at a slow enough speed so you can see them in time. Two million people attempt to use Birmingham's magnificent rail network every year, with just over a million of them managing to get further than Smethwick. Last edited: 15/04/2015 at 11:14 by Jan Log in to reply |