N&W Bicentennial celebration equipment

NW Mailing List nw-mailing-list at nwhs.org
Thu Mar 17 11:17:22 EDT 2016


Seeing that old Automatic Car Identification plate brought back memories for me.  When it became obvious that the railroad industry's decision to go to the optical ACI system was based on hastily performed testing and that the failures of the system were becoming obvious to all, an Association of American Railroads committee was formed to see what could be done to correct the shortcomings.  Most of the railroad representatives on the committee were communication and signal department specialists, but I was appointed to the committee from the N&W Motive Power Department.  After a number of meetings and field inspections, the committee concluded that a new ACI system would be needed.

Next, a new AAR committee, designated "New Concepts in ACI," was formed, and I was appointed to this committee also.  Again, most of the other committee members were C&S specialists.  We reviewed several potential ACI system, one of the most intriguing of which incorporated (as best as I remember it) a transponder underneath the car which had a array of cavities open at the bottom, and each cavity could be "tuned" by moving a small rod in each cavity up or down, each tuned cavity representing a letter or a numeral in the car reporting marks.  An interrogator between the rails would send a microwave beam up to the transponder and each cavity would respond with a frequency depending on its tuning.  This elaborate system was not recommended by the committee.  What the committee recommended was another microwave system which was essentially the system in use today.

Gordon Hamilton

  ----- Original Message ----- 
  From: NW Mailing List 
  To: NW Mailing List 
  Sent: Thursday, March 17, 2016 7:06 AM
  Subject: Re: N&W Bicentennial celebration equipment

    turned to road-side scanners that produced a print-out of the
    train.  Known as ACI (Automatic Car Identification),equipment
    (including cabooses) were fitted with ACI labels.  You've
    probably seen them -- colored ribbons arranged horizontally on
    a black backing pasted on the side of the car.  From memory,
    the ACI label had fourteen stripes (+ or -)  enough to identify
    an ATSF car with six digits.

  Quite a few years ago, I found in the weeds off a right of way one of the black ACI plates that had finally given up and detached itself from a passing car. Based on the barcode (starting on the left), the N&W was the car owner (stripes 2-5) of car no. 12905 (stripes 6-11). Stripe 1 is the "Start" and stripe 12 is "Stop" with the last stripe (8) is the check digit.
  This has been hanging in my basement, but I am willing to part with it for the archives.

  Bruce in Blacksburg



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