Amtrak Dual Equips Part of NEC for I-ETMS PTC System

Effective April 23rd, 2020, Amtrak is activating I-ETMS (Interoperable Electronic Train Management System) on its Philadelphia to Washington route between PENN and the end of CTEC territory at CP-AVENUE and on the Harrisburg Line between FRAZER and STATE.  This is the PTC system generally used outside of the Northeast commuter zone by the Class 1's and other railroads and on Amtrak territory I-ETMS will be used by NS freights and MARC commuter trains.  The bulletin order with the relevant information can be found here.

Here are some important takeaways regarding this bulletin order.

1.  I-ETMS relies on the cab signal system to enforce train separation as a CSS failure will constitute an I-ETMS failure.  This was generally suspected to be the case due to the lack of I-ETMS antennas at intermediate signal locations in cab signal territory both on NS and on Amtrak. 

   "Trains operating with I-ETMS that experience a cab signal, ATC, Speed Control or LSL failure enroute must consider I-ETMS to be inoperative and proceed in accordance with SI 592-S2."

2.  Some MARC Locomotives were ACSES equipped for NEC operation, but as of 2018 MARC was still ACSES exempt.  MARC now appears to be switching over to I-ETMS, but I am unsure if it is because the locomotives can only support one PTC system or simply want to simplify procedures as the Camden and Brunswick lines as CSX will use I-ETMS.
   
   

   

   ACSES receiver on a MARC MP36 locomotive. 

    
3.  I am still working to get the instructions for the I-ETMS on board apparatus, but the I-ETMS special instructions make reference to time consuming software downloads, manual entry of consist weight and manual selection of track before entry into I-ETMS territory. All of this manual entry through what is probably a fairly simplistic interface device is likely what led to METRA's complaints about PTC setup times of 10-15 minutes necessitating schedule changes.  ACSES does not require complex setup procedures due to the use of transponders.
4. The rules state that the Stop release becomes available after 300 seconds (5 minutes) stopped within 1500 feet of a stop signal, but I was told that might be a typo as 30 seconds would be a more reasonable amount of time.
5. It will be interesting to see how the two systems stack up regarding braking curves and calculated enforcement points.
6. SEPTA's claims that ACSES was incompatible with I-ETMS to justify separating the West Trenton branch from the CSX Trenton line were not entirely truthful.  The 2015/16 project cost a good deal of money and reduced capacity on the West Trenton Line with SEPTA claiming it was out of their hands.  As I pointed out at the time there was nothing that would technically prevent deploying both systems on the same section of track and Amtrak has proven this assertion without much fuss or fanfare. 

Anyway, that's all I have.  MARC riders, keep your eyes open to see how I-ETMS effects performance.  I'll follow up and try to get the answers to the lingering questions.