Rebuilt CN mechanical reefer 3D print

For years one of the projects that has lurked in the back of my mind was the CN 222600 series mechanical reefers that were rebuilt from CN's fleet of 8 hatch ice reefers. These mechanical reefers were staples on the Hudson Bay passenger train from the 1960's through 1983. CN rebuilt a significant portion of their 8 hatch ice reefer fleet into mechanical reefers in the 1960's as these were relatively new cars (the last cars were built in the late 1950's) that were obsolete due to the advent of mechanical refrigeration.  

The rebuilding process included plating over the roof hatches, adding full height plug doors, underslung genset, fuel tank, battery box and other equipment along with an A/C unit on one of the doors. The 222600 series cars also had steam lines for use in passenger service. CN also converted other cars with a 5' tall plug door. Other similar cars were in the 220xxx, 224xxx and 225xxx series, and likely others as well. CN's freight car renumbering efforts in the 1960's and 1970's will make your head spin.  

For the past few weeks I've been working with my good friend Tim S on this freight car.  Tim is a 3D CAD guru, he has forgotten more about 3D CAD than I will ever know. We both share an interest in all things northern Manitoba so this is a natural project for us. 

The 3D CAD file in the slicing program, ready to get set up to print

This is one of the test print bodies: one thing I found out is that as much resin gets used making the supports for the project as is used in the actual project itself

I did the printing, test fitting and building of the car. After lots of back and forth on design, car features and some practical "how does it print" testing, we have a finished car. I have a pile of "decent but not quite there" shells and underframes that I'll figure out something to do with. Lessons include not printing multiple bodies until the various issues have been resolved. I could have saved a fair bit of print time (and resin) by being less ambitious on print volumes.

The car body was primed to check for any blemishes or deep print lines. These were fixed as described below

A reality of 3D printing is that occasionally you will get deep print lines: an easy fix is to use Bondo Spot Putty (the kind they use for fixing cars) and patch any objectionable lines and blemishes.  I trim 600 and 1000 grit sandpaper to fit between the panel lines to sand and smooth the patches.  When finished you can barely see the lines. If there are a lot of print lines you can do an overall sanding of the body (between the rivet strips on the panels) to smooth out the lines. Current printers have barely noticeable print lines. 

I primed the body again after fixing lines and blemishes.  The main car body was painted with TruColor Silver paint. We printed the doors as separate parts to simplify painting - masking over the door rods is a pain if it is part of the body.  The 222600 cars all had red doors, with the A/C unit painted blue.  I don't know if it was originally CN Blue, but the colour faded quickly to a light blue colour so I went with that. I used Tamiya X-7 Red for the doors and Vallejo 71-333 for the blue A/C unit.  The underframe was painted Tamiya X-1 Black. Future cars will likely be painted with Vallejo paints simply because mixing the various paint types did cause some minor issues with adhesion and touch ups. I also added air hoses and a steam line connection to both ends of the car.

Black Cat Decals makes the correct lettering for this car in set CN 214152.  It has all the necessary lettering except for the ACI label and the yellow "no roofwalk" label.  These were taken from a Microscale (MC-4280) and Black Cat boxcar set (CN 525303) respectively.

I'll need a fleet of these for the Hudson Bay passenger train, as well as some general freight use cars. Tim will need a couple for his layout as well. There are some other potential cars still to come. 

Almost every photo of these cars shows them with varying levels of filth. Mark Perry Photo Thompson MB 1983. Used with permission

Whoever  came up with the paint scheme on these cars deserves a design award: silver body with red doors and black lettering is very pleasing to the eye. Next up is to weather these cars to within an inch of their lives. They were absolutely filthy, with it being very difficult to tell if they were actually silver instead of a dirt brown colour.

March 27, 2026 update    

Another four cars are ready for service.  Two will be heading to Tim's layout after getting weathered.