OK, so after months of not touching this project (finishing my
BNSF PF conversion), I finally got back to the OTM Tracker project.
I will rehash it all (briefly):
This started with the OTM Tracker presented in RailBricks issue #6. From there, I updated the cab of the truck to look more modern. I added in the couplers (which were missing in RailBricks), redesigned the hydraulic support pylons, moved the hi-rail wheels to be more realistic and stable on track, and even added in some tool boxes.
I also redesigned some of the crane, particularly the “legs”. I actually operated one of these machines in the late 90’s, so I wanted to make the “legs” more realistic and workable (the workable part will probably require some continued redesign, but its better for now). The cab will slide the entire length of the beam in my design, and I completely redesigned the crane arm.

Here is the OTM Tracker in the travel position. The crane sits very stable on the bed of the truck, and will a little effort, you can get the crane arm into an acceptable position for road travel.

Here is the OTM Tracker getting up on the Hi-Rails to travel the rails. The second picture shows the gondola I added for the this project (which needs to be longer than my 24 stud version to allow the crane of actually sit on top and still have access to the car…you will see in a minute what I mean). Note the Hi-Rail wheels tuck up neatly inside the frame of the truck, preventing any issues when driving on the road (all this without compromising strength in the frame).

Here is the OTM Tracker preparing to off load the crane. The hydraulic support pylons work (I need to shorten the tops eventually so they minimize interference with the crane). The real truck has a pretty elaborate system that actually lifts the crane up to the same height of the gondola car, but I omitted that part (for now….).

Here is the OTM Tracker working from a gondola car. The “legs” at each end of the beam did not turn out as stable (or functional) as I had planned (hoped), so it may be in for a design in the future. There was also supposed to be some hinged part that actually clamped onto the gondola (again, they didn’t come out as envisioned), so right now it is just sitting there. You can see that the crane (18 studs long) it a bit too big for the gondola car to actually have access to it, so I think I will redo the gondola to be 28-32 studs long.
The Brandt and OTM Tracker decals were created using the corporate logos, and the red danger stripes were added to “pinch points” on the crane. All were custom made using Papillio white vinyl inkjet sticker paper (great product IMO).
I hope you enjoy this. My redesigns will probably wait for me to get done with my next project, so it may be a while before I update this.