CN’s Rail Inspection Portals

CN's Rail Inspection Portals near Winnipeg, Manitoba
CN’s Rail Inspection Portals near Winnipeg, Manitoba

In May 2018, CN awarded a contract to Duos Technologies to provide four Rail Inspection Portals (rip®) around Winnipeg, Manitoba to perform automated inspection of passing trains. These portals incorporate high speed cameras and thermal imaging to inspect rail cars at speeds up to 70 MPH (110 km/hr).

These portals are now in operation, and CN is clearly happy enough with them that it placed an order for three additional portals in November 2018. Two of these portals will be built in the US and one in Canada, I believe near Toronto.

How They Work

LED lights
LED lights

The portal has high speed cameras mounted on the sides, top and bottom of a frame that encloses a track. These cameras basically take a series of thin, very tall “slice” photos that are stitched together by the system’s software into a complete picture of a rail car.

The portals are equipped with banks of LEDs to light up the train as it passes through, so they can be used at any time of day.

The portal also reads the AEI (Automatic Equipment Identification) tag on every rail car so it can match the image to a particular car. This information is combined into an operator interface like this (from the Duostech RIP System video):

Duostech Operator Interface
Duostech Operator Interface

Note the labels matching the car or locomotive number to the image, and the different views. Locomotive FXE 4814 is shown from the top as well as from both sides.

Taking pictures is great, but the real value of the system is the automated analysis of the images. Duos has optional modules that can be purchased to do things like this:

  • Boxcar open door identification
  • Missing/open hopper door hatch identifications
  • Detection of train riders
  • Pantograph inspections
  • Thermal imaging for “hot spots”

As a software guy, the applications for this image data are what are really interesting to me. I imagine they will build up a library of rail car types (and maybe even specific rail cars) and then the system can automatically highlight cars that are “different” from the norm. Imagine unit trains going back and forth through these detectors, and the system noticing that one car has changed from the last time it came through. A human operator could then look at the images to determine what the issue is.

It would have to filter out things like snow clinging to a car, graffiti sprayed on a car, etc. so there are definitely a lot of “smarts” required in the software.

Now we’ll look at each of the four portals around Winnipeg.


Rail portal under construction in Winnipeg
Rail portal under construction in Winnipeg

The first rail portal was well under construction by September 2018 in the south end of Winnipeg, on the CN Letellier subdivision that runs between Winnipeg and the US border at Emerson. This portal is visible from the Perimeter Highway, which you can see in the background.

I first noticed the portal in September 2018. By mid October, the protective shell around the detector was mostly complete, although it was still being worked on then.

October 2018 - note rails in ground
October 2018 – note rails in ground

Note the rails in the ground in the photo above. I believe those were for the UGG grain elevator that used to be here, although I could be wrong.

This portal is in operation, but I have yet to see it working with a train running through it. There are only a few trains a day on this subdivision, so it is a matter of luck and persistence.


The rail car inspection portal at Vivian, Manitoba
The rail car inspection portal at Vivian, Manitoba

East of Winnipeg, a portal was built next to the community of Vivian. This small town already has a hotbox detector – featured in my article Robot Railfans over on the excellent Trackside Photographer site.

When I visited Vivian in November 2018, the portal was not yet in service. I parked in the town, and hiked through the snow to see the detector. On the way there, I startled this deer.

"Whatcha doing out here?"
“Whatcha doing out here?”

While I was slogging through the snow, I heard a distant horn. Train!

It turned out to be a westbound container train, led by CN 5655.

CN 5655 at Vivian, Manitoba
CN 5655 at Vivian, Manitoba

The portal did not light up as the train went through, so I don’t think it was quite in service yet. Before the train arrived, I did hear some fans or something like that, so I think it had heaters running. Still, it was pretty neat to see a train go through it.

Containers going through the rail inspection portal at Vivian
Containers going through the rail inspection portal at Vivian

There is a road crossing in Vivian and another just west of the town. I think it would be interesting to try a zoom lens at those locations to get a more “head on” look at a train going through. Here’s a video by Jim Burnside from one of those crossings.

Running through the portal at Vivian – Jim Burnside video

I packed up, walked back to my car, and headed back toward Winnipeg. It turned out that CN 5655 stopped at Anola so I was able to grab this view of the lead engine, lit by the setting sun.

CN 5655
CN 5655


Rail inspection portal at Nattress, MB
Rail inspection portal at Nattress, MB

I wrote about my adventures trying to find the portal at Nattress, and finally finding it, so I won’t repeat those here.

Sainte Anne

Rail inspection portal between Sainte Anne and Dufresne, MB
Rail inspection portal between Sainte Anne and Dufresne, MB

I first saw the rail inspection portal near Sainte Anne, Manitoba in late October 2018. It was still under construction at this time, and when I visited, no trains came along. This portal is very accessible, visible from highway 12, with road 207 to Dufresne running right beside it. The photo above shows the portal with the grain elevator at Dufresne visible at far left.

I went back again in early February 2019, on a very cold afternoon, and I was fortunate to catch a train going through it. CN 2314 was powering a container train westward on the CN Sprague subdivision.

CN 2314 entering the rail inspection portal
CN 2314 entering the rail inspection portal

My understanding is that the portal is designed to light up after the lead locomotive enters. It didn’t light up here until after the loco was through the portal.

Scanning... scanning...
Scanning… scanning…

Here’s a closeup of the train rolling through. The train is lit and photographed on both sides, top and underside.

Closeup of the rail portal in action

My buddy Jim Burnside was at the Sainte Anne portal on the same day, but we didn’t see each other. He recorded a video of a train running through the portal.

Another Jim Burnside video!

Here’s a video I took of an eastbound train going through the St. Anne portal in April 2019.

Other Inspection Portals

Union Pacific posted a video of some research and development they were doing into machine vision. I don’t know if they went beyond this (the video is from 2016) but it’s interesting!

I hope to get out and take more photos of trains going through these portals.

I’d love to know how well they are working for CN!

12 thoughts on “CN’s Rail Inspection Portals”

  1. Hi Steve,
    In past blogs you’ve mentioned that the “telephoto lens” is your best friend or similar comments. That’s only half right. With a telephoto lens one has to be very
    careful. For example if shooting along a mainline with a loooooong lens it “can”
    make the track look very rough as it will amplify every little impurity in the track
    structure. The end result is what looks like “very poor track” when the reality is
    quite different.

    • Hi Ian, that’s true, a telephoto lens will “compress” the scene and any bumps in the track look magnified. It is a bit of a reality distortion… as the photographer, you have to decide if you like that effect or not.

  2. Thank you for sharing this. I lived in the Kingston area of Ontario along the CN line and never heard of an inspection portal. Its a great idea that I hope they will implication more of. You are obviously more dedicated than most as you don’t let the cold stop you. Great information and awesome pics so thanks

    • Hi Andrew, I think we’ll see a lot more of these portals around.

      If I let the cold stop me, I’d stop railfanning for half the year! 😉

      Thanks for your comment!

  3. I was a CNR car inspector at Walkley yard Ottawa in the 60′ 70′ and retired in 1986.
    This is a far cry from walking yard inspection, where sounds and smell were major details, but this is 2020 and no one can stop modernization and cost control.
    I am pleased to see these new camera systems, I now know what replaced us car inspectors and not convinced it is better.

    • Hi Jacques, yes, it is definitely different than the walking yard inspections. These are intended for rolling inspections more than the “car knocker” inspections – which have definitely changed too.


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