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Not ready for prime time
Author: Ernest H. Robl
Date: 10-14-2015 - 15:10
A couple of years ago, a Class I railroad official actually involved in the testing of PTC told me that under certain concidtions, in difficult terrain (inside steep valleys, etc.), where the on-board unit could not receive signals from the requisite number of GPS satellites (don't remember the number) the margin of error for PTC was around 15 feet. Guess what, some older tracks are built on 15-foot centers. In other words, in these situations, the system may not be able to tell which track the train is on!
In this conversation, which was off the record (not for attribution), this official also said that there were a number of other potential problems that would not come to light until the system was widely implemented. Yet, he said, his railroad had no choice but to go with the hardware and software that was available.
He agreed with me that there were some European signaling solutions that could have been bought "off the shelf" that (1) would have done essentially everything that PTC was supposed to do and (2) did not require the use of GPS satellites.
-- Ernest
In this conversation, which was off the record (not for attribution), this official also said that there were a number of other potential problems that would not come to light until the system was widely implemented. Yet, he said, his railroad had no choice but to go with the hardware and software that was available.
He agreed with me that there were some European signaling solutions that could have been bought "off the shelf" that (1) would have done essentially everything that PTC was supposed to do and (2) did not require the use of GPS satellites.
-- Ernest
