I use DOS regularly. I maintain a product for my company that is a PC based programmable protocol converter and logic processor, for use in the rail industry. It has been running on DOS for something like 15 years now, and will continue to do so for the forseeable future.
I don't know, I'm more than happy to associate the concepts of Microsoft and IsNot together. Microsoft 'IsNot' my software provider of choice, Microsoft 'IsNot' able to produce reliable, well tested software, Microsoft 'IsNot'...
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?
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One wonders, though, how many bugs have gone unfixed in IIS?
I think it has been made pretty clear already, but for the record....
15 + 2yrs relationship development + 2yrs relationship recovery = 19.
RTFA, my friend.
This from a slashdotter? That's rich!
Is a diety like a god of weight loss?
Last time I checked he was a computer scientist, not a taxidermist.
I use DOS regularly. I maintain a product for my company that is a PC based programmable protocol converter and logic processor, for use in the rail industry. It has been running on DOS for something like 15 years now, and will continue to do so for the forseeable future.
It works. So why change it?
I don't know, I'm more than happy to associate the concepts of Microsoft and IsNot together. Microsoft 'IsNot' my software provider of choice, Microsoft 'IsNot' able to produce reliable, well tested software, Microsoft 'IsNot'...
Government's more interested in keeping their secrets, and Bruce Willis can't always be around to look out for them!
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?