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Post by brigham on Apr 12, 2019 7:57:54 GMT
The prep/service system becomes both simple and foolproof, once you grasp the difference between post-prep time, and time in service.
What would be gained by changing it?
(Other than taking money out of peoples' pockets. Again.)
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Chris M
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Post by Chris M on Apr 12, 2019 9:42:07 GMT
I think the simplest way to describe it (if I've understood it correctly) is that there are two clocks:
Clock 1 is the prep clock. This starts when a check is completed and runs for 24 hours.
Clock 2 is the service clock. This starts when a train enters service for the first time since the last prep and also runs for 24 hours.
A train can only enter service while the prep clock is running, but may enter and leave service an unlimited number of times during that 24 hours.
A train that is in service when the prep clock expires may continue in service as long as the service clock is still running.
A train that is in service when the service clock runs out must leave service (a) immediately, if it is at a station; or (b) the next station if it is between stations.
A train may not enter service when either clock has run out.
A new prep resets both clocks.
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Colin
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Post by Colin on Apr 12, 2019 15:53:12 GMT
The prep/service system becomes both simple and foolproof, once you grasp the difference between post-prep time, and time in service. What would be gained by changing it? Exactly! I think the simplest way to describe it (if I've understood it correctly) is that there are two clocks: Clock 1 is the prep clock. This starts when a check is completed and runs for 24 hours. Clock 2 is the service clock. This starts when a train enters service for the first time since the last prep and also runs for 24 hours. A train can only enter service while the prep clock is running, but may enter and leave service an unlimited number of times during that 24 hours. A train that is in service when the prep clock expires may continue in service as long as the service clock is still running. A train that is in service when the service clock runs out must leave service (a) immediately, if it is at a station; or (b) the next station if it is between stations. A train may not enter service when either clock has run out. A new prep resets both clocks. Yep, that's it. We got there in the end  |
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rincew1nd
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Post by rincew1nd on Apr 12, 2019 22:54:35 GMT
A train that is in service when the service clock runs out must leave service (a) immediately, if it is at a station; or (b) the next station if it is between stations. So the next question becomes, who monitors the service clock and how? I would expect the S Stock to have it built into the computer wizzardry somehow, but for the older stuff? Ok a driver taking a train out of a depot might know and/or be able to work it out from the details in the book where the prep time was recorded, but what about a train op relieving another in service? |
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Colin
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Post by Colin on Apr 13, 2019 0:27:54 GMT
So the next question becomes, who monitors the service clock and how? I would expect the S Stock to have it built into the computer wizzardry somehow, but for the older stuff? Ok a driver taking a train out of a depot might know and/or be able to work it out from the details in the book where the prep time was recorded, but what about a train op relieving another in service? Because trains are usually prepped by depot staff after they stable at the end of their working day, they will almost always have been done between the hours of 20:00 and 02:00 Given that night tube is only two nights a week, and only on half the lines, for the most part the most a train will ever do is 20 hours in service (05:00 start till 01:00 stable). And when it stables the next evening it gets prepped again sometime between 20:00 and 02:00, and so the cycle repeats. As I've said a few times already, night tube lines will put out freshly preppped trains with a new service clock around 23:00 on Friday and Saturday nights to cover the night tube service so this in itself will naturally mitigate the chances of a train exceeding its 24 hour service clock. The main risk is reforms around the transition to and from night tube. Service Controllers have access to a train maintainer within control rooms these days and they'll refer to them if there's a question mark over a particular train. Equally, the control room train maintainer might spot that a train has been out too long and can bring that to the attention of the service controller. Depots themselves may also be looking for a particular train and can "recall" it via the control room train technician or by contacting the service controller directly - this can happen at any time of day on any day of the week. The risk of a train exceeding its 24 hour service clock is so low, its almost impossible to achieve. |
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Chris M
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Post by Chris M on May 14, 2019 16:56:59 GMT
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class411
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Post by class411 on May 14, 2019 19:24:59 GMT
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