Tom
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Signalfel?
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Post by Tom on Aug 30, 2005 18:36:20 GMT
In fact, even overshooting a stop diamond while proceeding under the authority of a shunt signal is a SPAD, despite the fact that stop diamonds haven't got sighting distances, overlaps, repeaters or trainstops.
While most SPADs have little adverse effect due to the overlap, I have known a train to very nearly become derailed after it passed a signal at danger and a set of points in the overlap moved just as the train SPADed.
Therefore while the majority of SPADs result in a train stopping a few feet beyond the signal and the driver getting relieved for interview with no harm done, they can, especially in high capacity areas or cramped layouts, become very dangerous.
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Post by Tomcakes on Aug 30, 2005 18:49:57 GMT
If SPADs aren't dangerous, when what are signals for? To use as fairy lights at christmas?
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Colin
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Post by Colin on Aug 30, 2005 21:17:37 GMT
Well my view is:
A red signal means danger. If you pass it, you have entered danger.
Therefore a SPAD is dangerous.
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Post by igelkotten on Aug 30, 2005 21:31:14 GMT
Looking at MA:s post, it is interesting to note that his statement is full of qualifiers: The train should be working perfectly well, the adhesion should be nominal, the train should not overspeed for any reason etc etc etc. And while that may be fine for a theoretical argument, it is not something I would want to trust in real life.
The problem is that signals might turn to red for any number of reasons. It might be because there is a train in a block ahead of it, within the planned overlap. It might also be because a set of points are in the process of throwing, or a crack developing in a rail joint, or someone applying a short circuiting device or whatever. And in those cases, the overlap might well be compromised to a larger or smaller degree.
Any reasonable railway operates on a "belt and suspenders" policy -that is, there should always be several barriers between a faulty function and an accident. By passing a signal at danger without following the correct procedures for doing so, you have removed one of those barriers. It should be OK, as long as everything else works OK. But how can you be assured of that?
Really, a single persons actions should never be the only barrier to an accident, but when you are doing a safety critical job, you should behave as if your actions were the only thing preventing an accident. If everything works out as it should, a SPAD isn't particularily dangerous. But the stakes are a bit too high for me to want to start gambling with them.
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Deleted
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Post by Deleted on Aug 31, 2005 14:56:44 GMT
<two penny goes in the slot>
I am not a train operator, so what I'm about to say is open for questions / comments / disagreements or whatever.
I think Mr I and Chris (I think - it doesn't display the thread history here....) have summed this up very well. Tripcocks and trainstops are great at recovering after the mistake (if I can call it that) has been made - they are an addtional safety feature. They are designed, quite correctly, to bring the train to a stand should a SPAD occur for whatever reason.
There are a multitude of reasons why a SPAD may theoretically occur - only one of these is driver error. In the 'one unders' thread Mr I talked about the problems of keeping humans awake and alert in monotonous environments. For whatever reasons, peoples minds wander - you cant help that. It only takes half a seconds mind wandering about what you're doing after work (as you've got 30 seconds til you're relieved), thinking about the game u saw last night, and you can hit a stick or end up at South Harrow. Nothing, short of converting to ATO, is ever going to stop this - we're humans, we get it wrong occasionally.
With regard the wristbands, it won't make a blind bit of difference if you have one or not - it won't stop you hitting a stick. What it might be, however, is a clever piece of PR by LUL to show the public that, outwardly, they are doing something to address SPADS. Whilst we all know a lot happens behind the scenes to address these, the public never sees them. Could this, therefore, be nothing other than a PR trick to assure / reassure the public? I don't know: maybe, maybe not.
<The floodgates are now open..........>
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Chris M
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Post by Chris M on Aug 31, 2005 15:16:35 GMT
<two penny goes in the slot> <snip> Could this, therefore, be nothing other than a PR trick to assure / reassure the public? I don't know: maybe, maybe not. The first thing that strikes me here is why just the Pic? To your average member of Joe Public (outside of London at any rate) LU is one organisation and don't understand the difference between the lines in terms of operation (I remember, years ago, to be suprised to see someone working in the ticket office at Westminster with an East London Line badge on, but none of my companions thought anything of it, even when I pointed out that the ELL doesn't go anywhere near Westminster station). I imagine that many people would be suprised to learn that a driver cannot drive on every line. Why not just "Professionalism prevents SPADs"? Chris |
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Deleted
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Post by Deleted on Aug 31, 2005 21:18:07 GMT
If the wristbands are a PR trick to assure/reassure the public, what methods are LU using to bring these to the attention of non LU staff.
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Chris M
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Post by Chris M on Aug 31, 2005 21:55:01 GMT
Thinking about it, I suspect that only a low percentage of the travelling public actually see the driver of the train, of those that do only a small percentage will see the driver in a situation where they have the potential to see whether they are wearing a wristband or not, let alone those that have a chance to read what it says. Everybody here knows how observant your average member of the travelling public is.... The only occasion I can think of (other than when I was purposefully looking for drivers at Earl's Court who knew DD, knew of the forum, knew where the forum meet was being held and would be prepared to tell a perfect stranger about it  (I didn't have any luck)) was when I was changing trains at Edgware Road from a District Line train to a H&C train to get me to Liverpool Street, there was a driver waiting to take over the same train. Even then I would have needed to be standing right next to him (I was about half a car length away) and looking at his wrist (I was looking for the train and making sure nobody attempted to make off with my bag) to have seen it. Given this, I don't think that the wrist bands function is likely to be to attract the public's attention to them. Or if they are then they're really not going to be particularly successful. Chris |
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Phil
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Post by Phil on Sept 1, 2005 8:40:17 GMT
A thought from your local Conspiracy Theorist: just suppose the Picc are NOT issuing them to t/ops (that would cost money!) but are only selling them on ebay. That way they make a profit and make the public aware they are active
BUt that still doesn't explain why ONLY the picc..
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Post by piccadillypilot on Sept 1, 2005 12:50:54 GMT
A thought from your local Conspiracy Theorist: ... BUt that still doesn't explain why ONLY the picc.. Testing the market? |
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Deleted
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Post by Deleted on Sept 1, 2005 14:15:33 GMT
BUt that still doesn't explain why ONLY the picc.. I beleive its not just the Picc. I have seen some others on different lines that are different to the PIcc ones... |
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(I didn't have any luck)) was when I was changing trains at Edgware Road from a District Line train to a H&C train to get me to Liverpool Street, there was a driver waiting to take over the same train. Even then I would have needed to be standing right next to him (I was about half a car length away) and looking at his wrist (I was looking for the train and making sure nobody attempted to make off with my bag) to have seen it.
