Device recommendation
I don't have any specific device suggestions but what is the use case? Assuming you have an area out of the elements to mount it you could use any old 12 volt tracker with a small battery and solar panel. Or possibly you could install the battery on an outdoor enclosure.
This use case is shipping containers in the us, more specifically the rail cars they sit on, so exposed and no power.
Are they ever going to be stacked? Maybe try browsing https://gurtam.com/en/gps-hardware. There are units that are intended for trailers and other assets with no available power that can run for extended periods on battery power, I would assume its at the expense of location update frequency.
Looking for a 4G (no 2g or 3g) solar powered GPS tracker for use on containers that allows me to use my own sim card. Any recommendations are much appreciated. gps at aseltine dot com is my email. Cheers