jis
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Thank you.
At the risk of going a bit off topic of the thread .... Actually, if you read the technical papers on ACSES, you will find that ACSES is installed in three segments. Segment 0 involved adding the additional cab signal pulse codes, and the additional speeds. Segment 1 involved adding the transponders for providing trains with location and civil speed enforcement information. PSRs (Permanent Speed Restrictions) are usually handled this way and primarily this provides the ability to enforce stops at home signals. Segment 2 was about adding the radio link to provide means for releasing a train from home signal failures and providing dynamic feed for TSRs (Temporary Speed Restrictions). Apparently the last segment is now being enhanced so that a train equipped with standard freight PTC equipment will be able to operate in ACSES equipped territory with ACSES providing the expected PTC radio messages. PTC equipped trains will use GPS position data and on board track data instead of transponder provided position and distance to target data.
Anyway, going back to the original subject, all diesels operated by Amtrak in the Northeast (including those that operate out of Boston, New York, Philadelphia and Washington) and all MNRR diesels are equipped with PRR cab signal system minimally. Amtrak diesels that operate commercially on the NEC must also have operational ACSES in them.
The reason that all diesels operating out of Washington must have cab signals is that RF&P to Richmond also has cab signal, and Amtrak generally does not allow an engine on a train to leave its origination point with cab signal inoperative under such circumstances. Incidentally the originally RF&P Cab Signal used 60Hz carrier frequency but the same pulse codes as on NEC. The carrier frequency on RF&P was change to 100Hz to match the first carrier frequency on the NEC, thus removing one compatibility headache.
The other thing that people don't realize is that there is lot of trackage in the east which has operating cab signals but still speeds above 79mph are not allowed on them. I have never quite figured out what the deal is with that. I suspect it may have something to do with having Cab Signal available but not required or some such - a cost and maintenance issue.
At the risk of going a bit off topic of the thread .... Actually, if you read the technical papers on ACSES, you will find that ACSES is installed in three segments. Segment 0 involved adding the additional cab signal pulse codes, and the additional speeds. Segment 1 involved adding the transponders for providing trains with location and civil speed enforcement information. PSRs (Permanent Speed Restrictions) are usually handled this way and primarily this provides the ability to enforce stops at home signals. Segment 2 was about adding the radio link to provide means for releasing a train from home signal failures and providing dynamic feed for TSRs (Temporary Speed Restrictions). Apparently the last segment is now being enhanced so that a train equipped with standard freight PTC equipment will be able to operate in ACSES equipped territory with ACSES providing the expected PTC radio messages. PTC equipped trains will use GPS position data and on board track data instead of transponder provided position and distance to target data.
Anyway, going back to the original subject, all diesels operated by Amtrak in the Northeast (including those that operate out of Boston, New York, Philadelphia and Washington) and all MNRR diesels are equipped with PRR cab signal system minimally. Amtrak diesels that operate commercially on the NEC must also have operational ACSES in them.
The reason that all diesels operating out of Washington must have cab signals is that RF&P to Richmond also has cab signal, and Amtrak generally does not allow an engine on a train to leave its origination point with cab signal inoperative under such circumstances. Incidentally the originally RF&P Cab Signal used 60Hz carrier frequency but the same pulse codes as on NEC. The carrier frequency on RF&P was change to 100Hz to match the first carrier frequency on the NEC, thus removing one compatibility headache.
The other thing that people don't realize is that there is lot of trackage in the east which has operating cab signals but still speeds above 79mph are not allowed on them. I have never quite figured out what the deal is with that. I suspect it may have something to do with having Cab Signal available but not required or some such - a cost and maintenance issue.
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