• PTC on Commuter Rail

  • Discussion relating to commuter rail, light rail, and subway operations of the MBTA.
Discussion relating to commuter rail, light rail, and subway operations of the MBTA.

Moderators: CRail, sery2831

  by twropr
I believe MBTA is using ACSES on its ex-New Haven lines so their equipment will be compatible with Amtrak when they run into South Station. On the Worcester Line is the "T" using ACSES? How 'bout the former B&M lines out of North Station?
Jacksonville, FL
  by 8th Notch
Amtrak sent a dedicated PTC trainset to the north side for ACSES testing on the north side a week or so ago so things are coming along.
  by Backshophoss
The only "kicker" is the lack of ab signals on the ex-B&M lines,part of the deal with Guilford on the sale to the MassDOT.
  by CRail
ACSES doesn't require cab signals.
  by Trinnau
ACSES was designed to overlay on ATC though. Why do you think MBTA is now installing ATC on the ex-B&M lines? They only got a temporary variance for use of it over the existing ABS system.
  by lordsigma12345
An ACSES without ATC deployment does have some differences because of the PTC requirement to provide for positive separation and avoiding movement through misaligned mainline switches. Such a setup requires installing additional wayside interface units on all the block signals where in the standard ACSES+ATC deployment they'd only be installed at interlockings/control points. They use the ACSES positive stop functionality to provide a degree of positive separation. If a block signal displays its most restrictive aspect (stop and proceed or restricting) or if the data radio in the locomotive fails to connect to the WIU a positive stop occurs and subsequently a restricted speed limit is then enforced for the duration of the block.
  by Trinnau
The MBTA's application allows a Stop & Proceed/Restricting signal to be passed at 15mph without requiring a positive stop. The radio communication failure still causes a Stop.

In either case the restricted speed limit is enforced for the entire block - or longer in some specific cases.