Make the trains run on thyme...?
How to make the trains run on time? Satellites. That's how
India has joined the gang of nations looking to make its trains run on time by using satellites. India's Ministry of Railways and Space Research Organisation (ISRO) this week signed a memorandum of understanding that “... aims for developing applications in the field of Remote sensing and Geographic Information System (GIS) …
COMMENTS
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Friday 18th March 2016 09:59 GMT Anonymous Coward
Re: Attention passengers
your 17:17 to Zurich will be on time but not in the right place, or will be in the right place but we're not sure what time?
If you see what the Swiss have cooked up to make trains run on time you appreciate why someone wants to do it with satellites. They collect so much data from so many sensors that they had to resort to using messaging kit normally used in trading to handle it all. If I'm not mistaken it all comes together in Zollikon.
Their delays are mainly due to passenger overload (there's only so much capacity, even with doubledecker trains), and the system is capable of then reworking the tables for the routes because they have a LOT of trains going on relatively few tracks. That reworking includes intermixing slow goods traffic with fast passenger trains, which makes for quite an impressive puzzle that needs to be solved on the fly every time there is a delay or a defect somewhere. It's IMHO a miracle that it works at all, let alone so well.
There used to be a live map of the system at swisstrains.ch, but the domain is for sale. Shame.
Accidents still happen, but even there their ability to cope with those is impressive.
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Friday 18th March 2016 07:13 GMT Ken Moorhouse
Fail-Safe
The question is whether such tracking engenders fail-safe operation of the railways. If I recall correctly satellite signals are attenuated by rain and as I understand it, parts of India have a lot of that. So, are the trains then delayed because of the weather? Or do you speculatively send a train down a long single-line track with no crossing points and gamble that "the other end" does not despatch a train at the same time? Even if preventative mechanisms kick-in if trains get too close to each other (in good weather conditions??) you still have the problem of knowing which train has the "right of way" and which has to be backed up to the last crossing-point - which goes right back to the original point of commissioning such a system:punctuality. There's a lot to be said for traditional signalling systems, or for spending the money on double-tracking the whole country, if that hasn't already been accomplished - but then there is the problem of dealing with track maintenance, which means shutting down one of those two lines whilst the other operates on single-line working principles.
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Friday 18th March 2016 07:38 GMT Anonymous Coward
Re: Fail-Safe
If only the professionals working on this had thought about safety and integrity issues while busily duct-taping their cheap satellite phone to the cab wall. Oh wait, they did! For the European system you could try following that space4rail link in the article, and maybe start with the 3InSat project.
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Friday 18th March 2016 07:50 GMT John Sager
Re: Fail-Safe
Well, the single track working problem was solved well over a century ago with the token system. Originally physical, with end-to-end interlocks between the token dispensers in the signal boxes, it's now often done electronically. No reason why they can't do that over satellites. That's what makes me so surprised about that head-on crash on a single track in Germany a few weeks ago.
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Friday 18th March 2016 09:12 GMT Anonymous Coward
Re: Fail-Safe - Rail magazine
"in the current edition of 'Rail' "
What's on the front cover (ie have I missed it in the shops yet)?
Alternatively is it, er, online? Couldn't quickly see it at
www.railmagazine.com
And while I'm here, anybody got any decent recommended (ie not Wikipedia itself) analysis of what went wrong in the Wenzhou high speed train crash?
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Monday 21st March 2016 13:46 GMT Anonymous Coward
Re: Fail-Safe
"article in the current edition of 'Rail' that describes the different systems for single line working that are currently employed in the UK."
Current edition means Issue 796 March 16-March 29 with "Structural defects force Heathrow 332 withdrawal" as the front page headline.
The single-line signalling article is on pages 72-76 but for some reason doesn't feature in the contents listing on page 5?
£3.80 at all fine newsagents, and selected supermarkets and motorway service stations.
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Friday 18th March 2016 13:00 GMT bazza
Re: Fail-Safe
The question is whether such tracking engenders fail-safe operation of the railways.
So long as it's done right, yes. Generally speaking you need everything to fail safe when the radio craps out, and not depend on radio to propagate the fail safe network-wide.
So if an emergency stop signal for a train is delivered by radio, that won't work. The signal may not arrive.
However if the train stops automatically if the radio craps out, that's better, so long as the signalling separation gives everything else time to realise there's a problem before one train hits another.
My biggest worry over things like this is that it's putting a lot of eggs in one basket. Lose the satellite and you're left with minimal train network capacity for years.
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Friday 18th March 2016 18:30 GMT PNGuinn
Re: Fail-Safe
Which in India probably means lots and lots of single line working, with right to the track still determined by possession of a mechanical token.
Somehow I'd have far more faith in a lump of brass in the driver's paw or round his neck than an incredibly complex and weather dependent .....
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Friday 18th March 2016 08:01 GMT Refugee from Windows
Not really necessary
Funnily enough trains run on predictable routes and don't have conflicting traffic to slow them down. Even then there are signalling and control systems that know where a train is, a system that's worked for over a century and seems to make them pretty safe.
Other factors can't really be controller by a satellite, it'd be a bit like problems in Discworld - you can know how much fresh prawns cost at their source but no chance of getting them to market!
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Friday 18th March 2016 13:05 GMT Stoneshop
Re: Not really necessary
and don't have conflicting traffic to slow them down.
They do. Maybe you wouldn't want to call all of the causes 'traffic', but that's beside the point.
In no particular order: wildlife, mechanical failures, suicides, yoofs playing silly buggers, electrical and/or comms failures, leaves on track, snow on track, other stuff on track*, human error**, sabotage.
* trees, vehicles, drunks, etc.
** Failing to top off the fuel tank (not as exciting as the Gimli Glider, but a problem nonetheless). A freight of steel sheets shifting during transport due to not being tied down securely and knocking several dozen catenary poles out of true. And much more of that.
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Friday 18th March 2016 15:27 GMT Doctor Syntax
Re: Not really necessary
"don't have conflicting traffic to slow them down"
Back in pre-denationalisation days when I commuted on the Chiltern line they'd frequently send a stopping service out just before a delayed through train. It wouldn't have mattered so much but they'd reduced a number of 4 line stations down to 2 so there was no chance to overtake.
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Friday 18th March 2016 09:01 GMT Charles 9
My question is how well would such a system work on a rail network with a lot of tunnels which would obscure the train's position when seen from above. And there's no guarantee a train will maintain speed within the tunnel. What if it breaks down inside and is too deep in to get a signal out?
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Saturday 19th March 2016 08:45 GMT Anonymous Coward
[GPS] Repeaters inside the tunnel.
If that was done the "obvious" way (a GPS antenna "up top", with the signal rebroadcast in the tunnel), I'm tempted to think that people in the tunnel would think they were in the same location as the original antenna, no? Maybe better than the satnav thinking you've been instantaneously transported 150 miles away to the last tunnel it was in, in Birmingham (I think that's what makes it happen), but...
All good stuff.
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Friday 18th March 2016 09:34 GMT Anonymous Coward
tunnels
"how well would such a system work on a rail network with a lot of tunnels which would obscure the train's position when seen from above. "
It would have to work better than my otherwise excellent CoPilot satnav software does in tunnels. Doesn't matter where the tunnel is, there's a 50% chance I'll instantly be transported to Birmingham. Then back to where I was. Then Birmingham. Etc. Till signal is restored.
Rail tunnels have a habit of being quite long in comparison with road tunnels.
"What if it breaks down inside and is too deep in to get a signal out?"
Existing mechanisms, e.g. track circuits, GSM-R? Otherwise, dunno.
I'm sort of getting a feeling of a satellite operator looking to sell a value added service here except the value added isn't entirely obvious, in general.
Original press release (?), for reference:
http://space4rail.esa.int/news/tracking-trains-satellite-premiere-for-europe
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Saturday 19th March 2016 01:17 GMT John Brown (no body)
Re: tunnels
"It would have to work better than my otherwise excellent CoPilot satnav software does in tunnels. Doesn't matter where the tunnel is, there's a 50% chance I'll instantly be transported to Birmingham. Then back to where I was. Then Birmingham. Etc. Till signal is restored."
LOL, that's a good one.
My Garmin guestimates where I am in the tunnel. If there's anything to slow me below the speed limit then it usually guesses wrong, but at least it tries. The only down side is one tunnel I use seems to have a blip in the map. There's a side road above the tunnel which is maybe 20 metres long and has been inaccessible for at least the last 5 years, but the Garmin map thinks that not only is it connected to the main road above the tunnel but the other end (a dead end) connects to the southbound tunnel 30 feet below. If I'm on the road above and wanting to go south, the routing tries to get me to drive down under the 30 feet of ground to get onto the tunnel road. If I'm in the tunnel going home, the routing tells me to exit the road at that point from 30 feet underground.
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Friday 18th March 2016 13:31 GMT Anonymous Coward
"India is of course very reliant on railways for passenger and freight movement because its roads are often deeply average."
You should try living in the South West, we dream of roads that are "deeply average". And as for rail-links, they haven't been significantly improved since Brunel's time.