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Post by xtmw on Jul 12, 2023 11:21:56 GMT
I think I remember seeing somewhere that the Jubilee Line ATO can run trains 'non-stopping' at all stations for one specific train or something like a train can have a sharper braking curve when running late. Would someone mind confirming these because I didn't realise Seltrac had all these capabilities.
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Post by starlight73 on Mar 2, 2024 12:14:39 GMT
I’ve done some digging on the forum and it seems both of these features exist. In the SSR resignalling thread, Colin wrote the following. (The “Northern line incident” is the runaway engineering train in 2010.) Not sure if station skip can be set up for unlimited stations or not. I still remember the Northern line incident a few years ago and although it was an exceptionally rare event it happened and a train carrying passengers had to skip stations and travel at higher than usual speeds. Quite possibly present-day safety systems would have thwarted the safe and happy outcome. Quite the opposite actually. Service control can set up station skip and trains will travel through platforms at 18mph under TBTC/CBTC. Under legacy signalling (as was in place on the Northern line at the time of the incident you refer to) trains had to pass station starters at 5mph unless an overlap allowed for a higher speed. About regulating trains to the timetable by varying speed: Jubilee TBTC does that if I’ve understood correctly. See this post from 2011 (not sure who wrote this, as their account is now deleted). TBTC can definitely regulate trains against the timetable, as a later post says, by way of the System Regulation Server part of TBTC. When a train arrives at a station its journey time to the next station is calculated to allow it to arrive on time and a suitable velocity issued to it. Note the calculation is made as the train arrives so if it subsequently has an extended dwell time the train will still use the same velocity, probably making it slightly late and the system will then recalculate and either reduce the dwell (but not below a specified minimum) or speed the train up for the next station to station run. Whilst the timetable still has a little slack in it compared to achievable run times there will still be some slower runs between stations if trains are predicted to run early (but often on the system at Neasden you can see a whole line worth of trains within 2 to 3 seconds of perfect on time running with zero intervention from staff). |
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Colin
Advisor
My preserved fire engine!
Posts: 11,310
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Post by Colin on Mar 4, 2024 10:10:52 GMT
I think I remember seeing somewhere that the Jubilee Line ATO can run trains 'non-stopping' at all stations for one specific train or something like a train can have a sharper braking curve when running late. Would someone mind confirming these because I didn't realise Seltrac had all these capabilities. With TBTC (Jubilee & Northern lines) and CBTC (C&H, District & Met) there's two ways to set up non stopping at stations. 1) For trains in passenger service, service control set up station skip and trains will travel through the platform area at 18mph - this is usually only done for a platform or station closure. It could in theory be used at multiple stations (ie, as in the Northern line runaway incident referred to above) but unless you've got a couple of stations closed in succession it'd be unusual to skip multiple stations. The likes of new years eve would be an odd exception where on the District for example Embankment & Westminster are closed at the same time - sometimes with Temple too. 2) For trains running out of service service control set up the signalling up so that the train is forced to stop at each platform and the driver has to re-start the train. The idea in this instance is to replace the driver OPO alarm system which is inoperative in ATO mode as otherwise a train could in theory travel from one end of the line to the other with a collapsed driver and no one would know till it reached the end of its journey. |
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