mrfs42
71E25683904T 172E6538094T
Big Hair Day
Posts: 5,922
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Post by mrfs42 on Dec 23, 2011 13:38:20 GMT
[snip]drivers won't be driving defensively when looming upon cautionary aspects. Although perhaps OT for this discussion per se, the concept of 'defensive driving' tends to make a bit of a mockery of a carefully designed signalling system. I realise that this is an old hobbyhorse of mine that I have mentioned on the forum before, but wearing a signalling hat: to my mind if a train slides past a signal and comes to a stand on the overlap of that same signal then the signalling system is doing exactly what it was designed for: there is no need for all the brouhaha about SPADs - if anything the fear of a SPAD has slowed the job up, making the job of the signalling designers harder.... |
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Post by jardine01 on Dec 23, 2011 13:38:32 GMT
ATO on the Mainline no way! It would take years to install lots of closures on a busy Mainline which mainline are we talking about here East Cost Mainline or West Coast? Also traveling at 125 mph in ATO? Pritty scary! Also the rolling stock uses some Diesel trains I.E the Intercity 125's. However am sure there is going to be a new breed of trains for the mainlines coming around 2019/20
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Post by br7mt on Dec 23, 2011 14:41:48 GMT
ERTMS Level 3 is said to use a very similar set of signalling principles to SelTrac S40 and probably all the other moving block ATP and ATO systems as well (Bombardier Cityflo, Invensys WestRace etc). Once you've got ATP implemented it isn't that big a technological leap to implement ATO. The principle challenge is to get the ATO control algorithm right and most of that is achieved anyway through the development work for ATP (brake rates and gradients for example).
Knowing how robust the safety case has to be before ATO is permitted, then yes, I would quite happily ride in an ATO train at 125mph or even faster.
Whether the cost / benefit ratio favours ATO though is a different matter entirely.
Regards,
Dan
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castlebar
Planners use hindsight, not foresight
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Post by castlebar on Dec 23, 2011 14:46:13 GMT
jardine 01 said "East Cost Mainline"
How very, very true.
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Post by eurostarengineer on Dec 23, 2011 15:32:31 GMT
Japans bullet trains have ATC which is pretty much ATO. 373's have VI and TVM430 which is pretty much ATO and 373s do 186mph, bullet trains are roughly the same I think.
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Deleted
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Post by Deleted on Dec 23, 2011 17:22:17 GMT
ATO operation on UK mainline is not far off. Probably the first line in the UK to use it will be Thameslink which will use ERTMS controlled ATO for the central section.
Frankly, just as for Crossrail there is little alternative if you want to push that many trains (24 12-car trains per hour!) safely and reliably through central London tunnels.
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Deleted
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Post by Deleted on Dec 23, 2011 22:26:10 GMT
Japans bullet trains have ATC which is pretty much ATO. 373's have VI and TVM430 which is pretty much ATO and 373s do 186mph, bullet trains are roughly the same I think. None of these systems are ATO. The driver has full control of the train and is supervised by the signalling system in place. VI is just cruise control. |
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Post by eurostarengineer on Dec 24, 2011 2:50:57 GMT
Notatraindriver.
May I ask you read my post again? I said its pretty much ATO. VI and ATC are basically on board ATO with no track based control. Speed under both systems and you'll be brought down to line speed amongst other things braking curves are produced as well as signal ahead status, upcoming and current signal/line status.
All things like in ATO, apart from the automatic acceleration of the train.
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Post by tubeprune on Dec 24, 2011 8:03:09 GMT
ATO makes no difference to train movement safety, it's the ATP that does that. ATO is simply allowing the train to accelerate automatically, which it can do anyway, and to brake to a stop at the right place, be it a station platform or a signal.
The real value in ATO is removing the variations in driver performance. This is important in metros where you need all the capacity you can squeeze out of the system. It is also becoming more important on those main line railways that are strapped for paths. I reckon you could get 10-15% more trains per hour with ATO just by removing the "defensive driving" that plagues our railways today.
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Deleted
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Post by Deleted on Dec 24, 2011 11:33:06 GMT
Notatraindriver. May I ask you read my post again? I said its pretty much ATO. VI and ATC are basically on board ATO with no track based control. Speed under both systems and you'll be brought down to line speed amongst other things braking curves are produced as well as signal ahead status, upcoming and current signal/line status. All things like in ATO, apart from the automatic acceleration of the train. Doesn't ATC stand for automatic train control? That means there *is* track based control. Vitesse Impose is just cruise control which the driver doesn't have to use if he/she doesn't want to. |
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Post by eurostarengineer on Dec 24, 2011 13:34:32 GMT
Sorry, worded the last post wrong. ATC doesn't use track circuit or other equipment to as tubeprune said "allow the train to automatically accelerate/brake" PTC is an advanced form of ATC.
All I'm saying is that both systems have the very basics (systems needed to retrofit ATO?) should it be decided to run with it.
Vitesse Imposée does also produce a braking curve should the train be speeding as it enters a marker board section. Again, another very basic system of speed control.
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