These are models for N-gauge model railway shipping containers in 2 of the most common formats 20 foot and 40 foot.
They print at lo-res in about 30 mins and use about 2.5meters of PLA.
Designed in OpenScad (files provided)
It was relatively simple as it is all a bunch of cubes - perfect for OpenScad.
The original sizes were found on the internet, then scaled by 160:1 to arrive at the right size for N-scale model trains.