Looking at pictures from the 1960’s and 1970’s I notice that locomotives and freight cars have what appears to be a color coded bar code. What was there use? I don’t see them on new cars anymore so when did they fall out of use?
Just what you called them, bar codes.
They didn’t make it too long…the dirt made it to hard for the visual scanners to recognize the codes.
They were replaced by the AEI system, the little gray rectangles you see on car at eye level, on the sill near the ends.
The purpose is to identify each car electronically, reporting mark and car number, so a clerk dosents have to try and hand write a list or train sheet.
The AEI, or Automatic Equipment Identification system used low frequency radio signals that activate the AEI tag to talk back to the scanner, it only works with in a few feet of the scanner.
About the only place I saw the old visual bars function was on the DM&IR at Proctor, MN. DMIR ran inbound ore trains thru a “bath” that tried to wash the bar codes just prior to the machine reading 'em. They had better than 90% accuracy largely because of the wash and that all the cars were nearly uniform in length and all bar codes were about the same height above the rail. Otherwise, the system was a flop.
This was an early attempt to read the cars - sort of a colored barcoe. The system was in part designed by 3M(they made the tags) and was tested on the DM&IR - the test looked good. The AAR decided to roll this out and the railroads started applying the tags(KARTRAK???). On the DM&IR the cars did not get slushed up as bad, and since the tags were all mounted the same on the ore cars, they worked very well. On the rest of the railroads, there were mounting issues and if the tags gote damaged or very dirty, they would read false. The entire proram was scrapped in the early to mid 70’s. The current AEI tags are a small plastic unit attached to the car. As a car passes the reader, a memory unit with the cars reporting marks burned into it transmits the info to the reader. The reader sort of charges the tag and it is alive & transmitting for a few seconds as the car passes the reader. These are use in other industrial applications as well(trailer/containers/etc…).
Jim
Actually, the Kar-Track system for Automatic Car Identification (ACI) was invented by Sylvania. The colored codes seen on some of the older cars yet today was a second generation of “bar-code” identification. An earlier version was used by Kansas City Southern (and perhaps others) for a time.
It was about 1966 or 1967 when ACI was mandated; this mandate lasted until 1978 or 1979. The system worked as long as labels were maintained, but the maintenance (and cleaning) took a lot more time and money than was originally anticipated.
Nonetheless, I use ACI nearly every day, in my hobby–many relettered and renumbered freight cars still have the ACI labels reflecting their (usually) original identity, and I can usually visually “scan” a clean one.
I know one bar code that “fell” out of use in about 1974 as the barcode bracket literally fell off the box car it was attached to and landed near the road. That bracket graced my wall for several years.
dd
Dirt, weathering, and vandalism. Do you suppose there were many members of the Brotherhood of Railway and Airline Clerks that were happy to see A.C.I. technology cut into their car checking duties? Over the years I saw a good number A.C.I. tags spritzed with spray paint, and not just by graffiti artists.
Actually it’s a microwave beam. The energy of the beam is captured by the A.E.I. tag and converted into just enough electricity to power a computer chip and radio transmitter. The tag transmits back the car’s initials and number, whether the tag is located nearer the A-end or B-end of the car, and the tag’s general condition. Each car in interchange service is supposed to have two tags - one on each side.
Unlike A.C.I., a technology that never achieved not much more than a 64 percent usefulness factor,
The handy part of any such system is that it can check the consist virtually anywhere. There is an RFI scanner located next to a crossing near me - several miles from the yard. I’m sure it’s tied into a computer somewhere, and every time a train passes, that scan is probably checked against what should be in the consist. In addition, the railroad now has a record of where ‘your’ car is, should you ask for status.
RFI tags are everywhere, even on compressed gas cylinders.
A more general term for this is “RFID”. I have seen stories that Wal Mart is considering requiring vendors to place tags on each pallet. One proposal was to put one on each item, so a shopper could just fill up a cart and roll it up to a register, which would then tabulate what’s inside without having to unload…not THAT one will take a lot of effort.
I wouldnt be surprised if the little Invenroty control devices, the white tabs which have to be de-senstised at the register, are a low power/low cost version of the RFID…
Albertson’s Grocery chain, in Texas, is already using this type of system.
There are quite a few “bugs” to work. It seems to me to take longer to check out.
Decals of the bar codes were/are available. I did nearly all mine at the time but leave them off now for the opbvious reasons. No one has ever commented on them though.
Many of my models have them. I won’t bother to take them off, but won’t add any more, either.
Those little white things inside packages are just metallic strips - open one up sometime. Sometimes you’ll find one in something you bought at a store that doesn’t have the sensors at the door. Then you go into a store that has the sensors and set the danged thing off…