I'm working on a restoration project that might require the recreation of a 1970s era ACI tag. Has anyone ever had one produced? How would you get the stripes "correct" to match a code for a certain car?

https://en.wikipedia.org/wiki/KarTrak

-otto-

It seems to me that much of the required information is available in the wikipedia link you provided. Each "tag" has 13 labels. The image to the right of the text in the "Design" section gives each of the 13 possible labels, starting with the "0" label at the top and ending with the "Stop" label at the bottom. Each of the labels shows a text representation of the value it encodes, in the bottom left corner of the label.

The link also shows the order in which the car information is encoded. So it is simply a case of substitution.

It might be challenging to determine whether the car was in railroad-owned, private-owned, or non-revenue service when the tag was applied. That info goes in the second label from the top.

You can get the owner code information from a link at the bottom of the wikipedia article. This info goes into labels 3 thru 5.

Labels 6 thru 11 are the car number. Leading 0s are prepended to make the least-significant digit of the car number occupy label 11.

The modulo-11 math can be challenging, but is also described in the wikipedia article and a link therein.

It should therefore be relatively easy to determine what labels to put on the tag, and in which order, for an accurate tag.

If you find this too challenging, I would be willing to help you figure out the right coding for a given car.

Regards,
Bob Milhaupt

Happy to see we are to the point where ACI labels are now being restored.

Has any group ever done a display on KarTrak ACI? Does anyone have a reader? This is such an important part of railroading history (and technology in general) that is overlooked.

Correction. Second line from the bottom. It is the first line of the four digit owner code.

Remember, tags are read bottom to top. Bottom line is Start, then the four digit owner code, then the six digit car number, then Stop, then the parity number on top.

It might be easier to just build a reader using current technology - a digital camera feeding into a computer, then writing code to identify each strip and generating a display after looking up the information from a database on the computer. Good luck finding parts to keep an original running!

I own a KarTrak reader. The difficulty isn't the reader itself, as much as it is the refrigerator sized computer that runs the whole show (which I do not own). Last I knew there were still a few surviving up on the Missabe in Minnesota (readers and computers), but they may all be gone by now. If you can get your hands on a reader, you can get the mirror assembly to spin and the xenon lamp to light up, which simulates the field conditions. As mentioned earlier, a small camera with a AI software to identify the bar codes would be the easiest way to preserve the identity of the system for a museum environment, etc.

Pretty sure those ACI tags used reflective tape (like most STOP signs). The reflective tape is needed for the system to work in total darkness and in bright sunlight;

https://reflectivetape.info/history_of_reflective_tape/

Might be hard to get that with the custom colors/patterns used in the original KarTrak system.

But you might get by with a laser printed color/pattern layer over a simple sheet of reflective tape behind each "stripe".

Perhaps this product;

https://www.uline.com/Product/Detail/S- ... -yds-White

With laser printed transparencies with the ACI patterns might work ?

(disclaimer; I have no affiliation with uline).

Cheers, Kevin

As for the old DM&IR ACI readers, I helped kill them off in the mid to late 2000's. Installed four or five SAIC / Comet AEI readers between Duluth and the mines for DM&IR / CN.

At that time I could not believe they were still running, but they were, thanks to begged / borrowed / scrounged parts from Chicago to keep the old computers going.

If someone needs a closer date of expiration, let me know and I'll dig through my old e-mail.

Otto,

We did a 1970s era restoration of a Minnesota Northfield & Southern boxcar and caboose several years ago and made up replacement barcodes for them that were then simply printed on an outdoor vinyl. (Sans-reflective properties, as we were on a budget...) But the end result turned out very nice. See pictures included.

To build the barcodes, I seem to remember considering future planning, and writing a web-based PHP script to take user input and then simply assemble the bar images in the correct order (yes, even with the correct check digit) as a single graphic that I then sent off to our local sign shop. Using Eric Neubauer's document on the subject (http://eaneubauer.ipower.com/aci.pdf) helps out in finding the correct railroad code. That was a couple of computers ago. I'll have to see if I have it backed up somewhere since we have yet to do any other ACI-era restorations. (Well, it was such a narrow span of time they were used...)

At our railcar shop, we are still occasionally getting 1970s-built hoppers that still have these stuck on. Third picture shows one that, all things considered, is in pretty decent condition. Note the little protector that was welded on to shield it from spilled commodity.

Rivet-counters will notice a slight difference in the STOP codes of my reproduction label and the PTLX label. Mine was based off the original barcode that was on MNS 408, so it appears that there were adjustments or variations in the specifications even when the system was in use.

- Mike Lewis, Wasatch Railroad Contractors

It's possible that a computer hobbyist could write the equivalent of a 'driver' for one of the nodding-mirror readers, and figure out a virtual-machine emulation of the old logic and programs (it sure wouldn't involve either too much processor or too many LOC!)

The idea of taking a 'staring' image and then essentially OCRing it to extract the sense if a much better approach in just about any respect. Of course this represents orders of magnitude more sophistication and power than anything extant in the operating days!

When I was figuring out how to port some of the Mac OS 4.2 UI to the System/36 many years ago, there were programs that could assign 'fields' to portions of an image, and other programs that could selectively interpret visual information in those fields and convert it (or call routines based on the information) as desired. It is possible that some of the older 'logic' could be used to parse information taken from a modern photograph in much the same way it would have been 'buffered' from a mechanical sequential reader...

In the 1974 edition of the Car and Locomotive Cyclopedia, (possibly 1970), there is a multi-page description of the system and its operation. I was looking for something else last night and got distracted by it and then moved on. Tonight I read this...

The free Iphone apps out there that read bar codes - and there are several - take a digital photo, then analyze the photo to read the bar code. I think that would be the best way to create a reader - an Iphone app. I don't think the modern laser/spinning-mirror scanners could handle the colors on the KarTrak bar codes, but I could be wrong about that. Have you reached out to one of the creators of the free apps on the Iphone to see if they could assist?

As for the original system - if you really wanted to use the original system - there have been PC emulators created for just about every paleo-system from the 1960s and 1970s. I have heard the original system described as refrigerator - sized and from IBM. Does anyone know exactly what type of system it was? System/36, for example?

Chris.

I'm hoping to have some made for my chessie caboose. I'm working on restoring it right now. Anyone wanna help with making the tag for C&O 3154?

Joe

I was fascinated by these labels back when they were new. They were Scotchlite "silver" on the white parts (not the pure white Scotchlite), and the white areas were printed over with small black dots, and the numbers were printed on one side of the stripes, and a clear coat over all stripes. The stripes were red, white, blue and black in various combinations. I would think that Otto has access to the Car and Locomotive Cyclopedia mentioned in a previous post.

I recall them having the thickness and consistency of those decals with the month and year you put on your car license tags, if you could ask the state who makes them I bet the manufacturer could make the ACI tags. Some of them weren't very sticky, you could peel them off and put them back on straight if you were OCD.