KarTrak.  Photo by John Keyes.
photo by John Keyes

The KarTrak system was developed by GTE Sylvania (Waltham, Massachusetts) in the 1960s to identify and track railroad cars and containers (e.g. SeaLand). It used a vertically-stacked series of color-coded reflective barcode labels from 3M to encode each car’s car number. The barcodes were read by mailbox-sized scanners installed trackside.

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

The KarTrak system gained wide-spread use in the late 1960s and 1970s, although by the late 1970s, it was largely abandoned. You can still spot the occassional KarTrak label on a railroad car. KarTrak is described in U.S. patents 3,225,177 and 3,275,477.

Online, more KarTrak information can be found within this PDF [no longer available online]. Some excerpts, which quote other publications:

The DM & IR [Duluth, Missabe and Iron Range Railroad installation is simple, yet effective. It depends on two unique system elements. A Sylvania KarTrak scanner and a permanent marking of Scotchlite reflective sheeting on the side of each car. The KarTrak scanner reads the special code marking of Scotchlite reflective sheeting. This pattern contains a start to read indication, room for variable information, and is followed by the empty or lightweight in long tons. The car number and the stop read mark. Both sides of the more than 9,000 cars and locomotives carry these markings. The KarTrak scanner turns on automatically as the train approaches. The scanner optically analyzes the identification markings, converts this information into electrical impulses, which are ultimately printed out on a tele-typewriter, paper or magnetic tape, or directly to a computer. This is made possible by feeding the electrical impulses from the scanner to the data processing equipment housed in this console. [Sylvania/3M promotional film]

By 1967 the [KarTrak] system was so successful that all North American railroads adopted the plan, followed soon after by the American Trucking Association, who put the codes on all trailers shipped by rail. At its high point, some seven years after its start, approximately 2,000,000 labeled cars, owned by 130 railroads, were spread over 135,000 miles of track. Most of the scanners were in place, the recording system was up and running, and the entire system was working the way it was planned. [Punch Cards To Bar Codes, 1997, p. 50, Benjamin Nelson]

By 1974, 95 percent of U.S. freight cars had been labeled. [The Bar Code Book, 1991, p. 13, Roger C. Palmer]

Update 3/17/2011: Just found this excellent article by David Jarrett Collins: Bar Codes: The 50th Anniversary of the First Bar Code Scanner.

Perhaps the earliest attempt at industry-wide use of bar codes was initiated in the late 1960s by the American Association of Railroads (AAR) to track railroad cars. It used a multi-colored bar code pattern and the first optical scanner to read the symbols.

This year, 2011, marks the 50th anniversary of the deployment of that first bar code scanner. It seems a suitable time to tell the story of how this development occurred.

Here’s a close-up of a well-worn KarTrak plate on Flickr.

Author: John


12 thoughts on “KarTrak”

  1. Very interesting. The crew that developed KarTrak must have all been geniuses before being struck down by excessive consumption of excellent and delicious prime steaks at the Pickwick in Duluth while installing the D M & IR system.

  2. Hello John;
    I typed Kartrak into search engine DuckDuckGo and got this page. In 1972 and 1973 I worked on the Kartrak system. The plant was GTE Sylvania in Lindenhurst, Long Island NY. I helped develop the scanner assembly. I also worked on the first style of memory using the thin sheets with holes in them. These were stacked on an assy. Current was passed through them and electronic pulses were read and interpreted by a tele- type system. The scanner had a spinning wheel with 11 mirrors. A bright lite was reflected out to the color coded id plate and the reflection was read by the scanner circuitry. It was a long time ago for me. I used to have several plates which I kept as mementos. Many moves and states they got lost but I do remember the technology somewhat. Thanks for your attention. Charlie

  3. What size were the plates? Can’t find that info anywhere, and I’d like to be able to produce some as home-made decals. They look to be about 12″ x 24″, but it would be good to know exact dimensions.

  4. Would any of you guys who worked on Kartrak scanners, have access to a operation and maintenance manual for one of the scanners? I recently picked one up as scrap, and have come upon the realization that very few of the actual scanners survive, as well as very few of the manuals! The plan is to get the scanner operational for a display exhibit, powering the wheel and the Xenon bulb…

    1. Philip–

      Where are you? I have some KarTrak stuff but NO ‘manuals’ or service literature. . . 😦

      Best – david –

    1. I have quite a bit of ‘KarTrak’ stuff. Where are you located? I’m in northern Cheshire County, NH, and IF it’s convenient for you I’d prefer to do a personal ‘show and tell.’

      Best – david –

      1. I’m in the Houston area.

        Do you have any code plates that attached to the rail car exterior?

      2. No, I don’t. 😦 What I have is the ‘track side’ equipment, scanner, ‘electronic rack,’ etc.

      3. Hi David-

        I’m in Wisconsin. I’d love to talk to you about your scanner and equipment. Any chance you could drop me a message? martin_ lumber AT yahoo DOT com. Thanks!

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