Bar codes

Model Railroader Prototype information for the modeler
1

When did bar codes such as the one on this D&M car come into use? When did they (or did they) stop using them??

[image]http://www.rr-fallenflags.org/dm/dm3057alr.jpg[/image]

Note: Image from Fallen Flags website.

2

Not sure the exact year, but I believe it was in the 60’s. I think it was dropped in the late 80’s partly because the bar codes would get so dirty the readers couldn’t read them anymore. Nowadays, they use a small electronic transponder on every car and loco. These transponders are about 2 inches high, about 8 inches long, and about 1/2 inch thick.

Brad

3

I’m not sure the exact dates, but they are called ACI (Automatic Car Indentification) tags, and were introduced in the late 1960s and abandoned by the mid to late 70s. The main problem was of course, they got dirty and the optical readers, could no longer read them.

The ACI tags have been replaced by AEI (Automatic Equipement Indentification) tags, which uses electronic induction to read the tag. This way they can be read when painted over, or covered with grime. AEI tags are the small gray rectangles on the corners of modern cars.

Nick

4

Thanks… Now that I know what it’s called, here’s a little more info for those interested…

http://en.wikipedia.org/wiki/Automatic_Equipment_Identification

As well as some other info, Dates included… Can’t speak for accuracy but they sound reasonable to me…

http://info.detnews.com/hotbox/hotboxstory/details.cfm?id=187

Edit: If you Really want to get into the nutz and bolts of it, Here’s the Patent… That is of the Newer RF based system??

http://freepatentsonline.com/4160522.pdf

5

I think they started about 1966, I believe the first RR to use ACI was the Missabe road on their ore cars. That way they could weigh a 180 car ore train more quickly because the reader read the info so fast they didn’t have to stop the car on the scales, just go over it very slowly.

6

From www.hosam.com:

ACI(Automatic Car Identification)plates were mandated by the F.R.A.
in 1968 and were to be installed on all equipment by 1970.
They were abandoned as impractical in 1978. After 1978 the plates could
be removed, but many were never removed. As the equipment passed by
the trackside scanner it was scanned. All information necessary
to keep track of the engine or car was then sent to a master location
where it was logged.
Dirt, scratches, fading from sunlight and vandalism all contributed
to the eventual failure of this system.
Placing these on your models will tie them to the post 1968 period.

What do the little stripes mean?

http://www.nakina.net/aci.html

7

Do you know of any online information on decoding the bar codes by owner?? That is, item number 3 on the list in the link you posted…

8

I seem to recall some railroads (DMIR?) setting up an automated device that sprayed the cars with a jet of water at the height of the ACI labels to clean them off before being read??