Re: positive train control
Author: COLLEX AKA COLLISION EXPERT
Date: 10-14-2011 - 20:36
OldPoleBurner Wrote:
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> PTS could have prevented it - more or less
> (assuming we ever get PTS to work right 100% of
> the time). Up until the point where the
> calculated braking distance (at whatever speed)
> exceeds the distance remaining to the target point
> (the restricting signal), PTS would have allowed
> the train to proceed being governed by the
> previous signal.
>
> But as soon as the calculated braking point was
> reached (or closely approached), either the
> engineer stops applies full braking at that point,
> or the PTS will - stopping the train BEFORE the
> signal is passed. That is because there is still
> adequate braking distance to the signal to do so.
>
> However, I said "more or less", because of what
> can happen next. After the enforced stop at a
> restricting signal (or a non-absolute), the PTS
> must then permit a restricted speed movement into
> the already occupied block ahead; simply because
> that is what the aspect is conveying.
>
> This is where even PTS cannot help much. It has no
> means to tell whether the crew actually observed
> switch positions or not - nor can it tell if the
> crew has taken note of a train or obstruction
> ahead. Worse yet, PTS cannot do these things for
> the crew anyway, as no means to reliably detect
> the exact position of any parked (or unequipped)
> vehicle has ever been invented. Moreover, a
> couple-up move under a restricted aspect must be
> allowed in any event. And that can still lead to
> a "Hard Couple!"
>
> So PTS will be of no help whatsoever when running
> on a restricting aspect, except for the initial
> stop and proceed part of it.
>
> OPB
hate to burst your bubble but you're thinking inside the box ... PTS is not like ATC ... it's a collision warning and collision avoidance system taking many factors and computerizing them into a situation ... in this situation with an oncoming train heading towards a stop signal and a train moving at a speed above the posted speed it most definately would prevent such an incident ... this guy blew by the signal because of
1: his inattentiveness and
2: his train speed well above the posted ...
had he been going 25mph the posted track speed he might have blew by the siganl but he would've had enough time to stop before kissing pilots ...
PTS will work off equipment with a GPS installed in the locomotives-it will also detect signal indication-switch alignment-block length-train speed-closing speed and simultaneously calculate a collision situation ... so if the system sees a train in a collision routing and the system detects a train speed above what the posted track speed as the case was here and the signal indication is restrictive (STOP OR RESTRICTING)in this case and detects a switch alignment headed into track holding a GPS equipped engine the system will shut the engine down and make an emergency brake application like a time penalty more than likely before the train even gets to the stop or restricting signal ... the system is designed to work preactive to prevent an incident not reactive after an infraction has already been made ...