Blender can work using real-world sizes, and indeed that is how you are supposed to work in Blender. I normally work in metric mode, because the metric system is far simpler to use, but after reading about standard US sizes for semi-trailers I went into imperial mode to see how long the trailer I bought was. It is 32 feet long, the smallest standard size for semi-trailers in the USA. By far the most common are 53 foot trailers so... I just could not resist, partly because it was easy to do. I cut the rear end off and moved it back, the cut out the section where the wheels are and duplicated it, then moved it back to join with the original. OK, you can imagine the rest easily enough. Once I had rejoined the newly positioned parts I had this magnificent beastie, a standard dry cargo 53 foot tandem-axle semi trailer! Great! Now my truck has more choice when hauling. I will of course be texturing both. Big trailers are often regarded as both working equipment and mobile billboards, so I will try to keep that in mind when deciding how to texture these trailers. And I have plans for another version of this 53 foot trailer, a most unusual one....