Slick kids, but they used to have some of those bomb-loading jammers at Barsto Truck Parts. Sadly it is defunct, and that was 25 years ago.
Now the transport story: A company named Bucyrus-Erie had a division in Pocatello Idaho that had the contract for reconditioning the 16 inch barrels for the various Battleships. The rebuilt barrels would be shipped to the edge of the Atomic Energy Site that is West of Idaho Falls to be proof tested, where they had a 16 inch gun. US-Subs has actually worked EOD-QC at that firing range. They would fire solid steel proof projectiles to test the barrels, and the projectiles would leave huge gouges in the terrain downrange of the gun. Before 911, security was pretty lax in that area, and enterprising scroungers would drive into the impact area to recover the projectiles for their own display use. Since the projectiles weighed around 3,000 lb., mistakes needed to be avoided during handling and transport. One less than careful guy dug a ramp into the ground so his pickup bed was down at projectile level on the ground. He then winched the big bullet into his pickup bed and headed for home. The story isn't clear as to if he chocked the projo, or if the chocks came loose, but when he drove around a corner, the projo rolled to one side of the truck bed, and the tire blew on that side. Gravity continued its part, and the moving projectile rolled the whole truck over.
So, preventing unexpected degrees of freedom during your trailering would be advised.