British Rail Moving Forward with Sat-Nav/GPS 192
de1orean writes "The BBC is reporting that after a successful limited trial using GPS satellite navigation to improve train safety and efficiency, British Rail is committed to instituting sat-nav throughout the system. It may be in operation as early as 2008."
Don't knw if anyone realizes this... (Score:3, Informative)
Re:First impression (Score:5, Informative)
In the end, well, trains don't always travel the same speed, they don't always travel at the speed they are told to. Sometimes they break down. Sometimes the switches aren't thrown properly (so there really are two dimensions, possibly more), sometimes a train runs away. Some times a train is on a section of track its not supposed to be. Trains aren't a trivial problem (we actually had to write a simulation of this in college in a RTS class, you had to do the computations and throw the switches at the right time, or you had yourself a fairly serious collision).
With trains at least, by the time anyone can visually tell you this, all you can really do is jump off and save yourself. It's literally a million pound weapon of death, by the time anyone can see the problem it's over. Having a GPS system on the train would enable you to spot all sorts of upcoming problems with out having to communicate with anyone onboard.
Kirby
BR (Score:2, Informative)
Lost trains not as uncommon as you might think (Score:5, Informative)
GPS is not so much to let the train driver know where he/she is (although that is a valid use under some control systems) as it is to let the train controllers and the safety interlocking systems know where the train is. This is obviously an important consideration before trying to place another train into that location ;-)
Historically there are rail systems around the world that do without this basic functionality, particularly in areas of low density traffic. Instead, procedures were established by which a section was proven clear. The signaller at the entrance to the section (or 'block') would ring a bell to let the signaller at the exit from the block know that a train was entering the block. The signaller at the exit would then ring a bell back to the signaller at the entrance when the train cleared the block section.
This worked to some extent (and indeed continues to work in many places around the world), but was highly susceptible to human error. A couple of years ago, at Glenbrook in Sydney's west, a crash may have been averted had the signaller had some indication to remind him that the Indian Pacific had not yet cleared the section ahead of the suburban passenger train. As it was, he forgot to inform the second train of the first's existence, with the result that the second rammed into the back of the first.
The most common method for establishing a train's locations is the track circuit - a power source is placed on one end of a section of track, whilst a receiver measures the voltage at the other end of the section. When the train is on the section, the axles of the train short out the circuit, and the receiver measures a 0V potential. This is fed back to the local interlocking, and any signals which require this track to be clear in order to give a proceed aspect will go to stop, preventing any other trains from entering the section and hence avoiding a crash. This is what the article refers to as the "current block signalling system".
The problem with track circuits is twofold. As mentioned in the article, the accuracy is not great - track circuits can often extend over several kilometres, so the best that can be said is that the train is "somewhere within that circuit". Secondly, the track circuits are relatively difficult to maintain - maintenance crews must go to each track circuit in order to perform routine maintenance. Travel time being relatively unproductive, rail operators would much prefer that maintenance be achievable in one location.
GPS would overcome both of the problems listed above. The accuracy would be greatly increased, limited only by the accuracy of the GPS. Similarly, the equipment for the location would all be located on the rollingstock, rather than trackside, and could be brought to the maintainers. Further, with systems like the European Rail Traffic Management System (ERTMS), GPS can be used to run trains much closer together in what is called a 'moving block configuration'.
This translates into lower running/maintenance costs, combined with greater efficiency - is it any wonder BR are interested? Aren't you?
Wrong, wrong, and wrong. (Score:4, Informative)
2) They're not "committed" to using it. "Key industry figures" (lobby groups?) had a meeting on Tuesday about whether to implement it system-wide. RTFA.
3) It won't be ready for service in 2008, that's when Galileo will be operational. RTFA.
Modernisation - British Style (Score:3, Informative)
The GPS one is a prime example. The door systems on the modern trains (the ones with sliding doors that don't have to be slammed shut and opened by reaching out of a window and fumbling for a lever) are GPS actuated. These doors will not allow passengers to open them unless the location of the train can automatically be established as being within a few metres of a normal station platform stopping point. The upshot? When it's cloudy or there is any kind of reception fault (as when we get back into London's Victoria station and we're under 20 ft of steel-reinforced concrete) the doors cannot be opened without the driver entering the positioning coordinates manually.
A driver was telling me that there is no 'look just open the bloody doors - I've got a key' button. So journey's all over the south coast are now delayed by really stupid door faults. Ironically the most reliable trains are the slam-door variety I mentioned earlier (which are eminently usable despite feeling like Stephenson's Rocket - unless you are in a wheelchair and then you can pretty much forget it).
Re:Modernisation - British Style (Score:3, Informative)
There is also a button to close the door, but rarely anyone pushes it. When the train is ready to depart, the conductor uses a key to close all doors except the one where the key is inserted. He looks if all doors have closed and nobody is stuck, then releases the key to shut the last door
This system existed way before GPS.
(indeed there were manual doors on older trains where you could open the door during the trip and all doors had to be closed manually)
This is rubbish.... (Score:2, Informative)
It was great in the summer, but not so great in the winter. When there were clouds. And no GPS reception.
We had to sit outside each station for 5 minutes while the driver got 'authorisation' to open the doors, becasue the GPS didn't know we were sitting beside the station.
Wonderfull bit of over engineering.
It's not British Rail (Score:5, Informative)
The article doesn't say, so it's reasonable for someone non-British to assume it's still called that, but it's probably Network Rail (formerly Railtrack) doing this. They are a now part-re-nationalised company that looks purely after the rails, stations and other non-profit making infrastructure. The private rail companies still own and (sometimes) run the trains and are doing very nicely thank you very much Mr Major (A stunning example of how privatisation actually works: Public funding, Private profit).
Rant over
Re:Modernisation - British Style (Score:3, Informative)
The slam-door trains also have a very useful feature known as a "guard's van" which is missing on modern trains, basically half a carriage of empty space.
Not only does that solve the wheelchair problem (large doors for wheelchairs, and there's a wheeled ramp on every platform to get wheelchairs into the guards van), but it means that you can have a combined bike/rail transport network (put bikes in the guards van) which is slowly being dismantled as they buy trains that you can't take bikes on.
GPS?! (Score:1, Informative)
(a) won't open in the main terminus (Victoria), so we have to wait about 30 seconds for the gurad / driver to wake-up and open them and
(b) which don't work properly even in stations in the opne (it's discouraging to hear that the driver needs to reboot the OBC to get the dorrs open - must be WindowsMe as it takes ages).