On my travels i have noted log trailers with no forward restraint to stop the goods they are hauling from crushing them if they had to stop sharpish, the logs would just go straight through the very thin metal at the back of the cab, then it is fatal or severly injured from a crash.
The log trailers seem to be hauling any thing that pays, which is fair enough, they are just trying to make a living, but i have seen metal pipes, no head board on the trailer.
The same with flat bed trailers, railway tracks with the concrete still attached, that had nothing to stop it going forward on to the driver in a crash, and heavy pipes, no restraint on them, and numerous types of heavy machinery on wide load trailers.
most of that type pf load you mention , it wouldn’t make much difference if there was a headboard , once it starts going it won’t stop . those loads have to treated with great respect . pipes especially are a nightmare to secure , it helped to rope every layer and strap over the top , but that isn’t foolproof .
I think you worry to much, your last posts seemed to be getting very close to the point of trolling as with this one, unless you have to pull the trailers whats the problem 
perhaps the key word is driver , as opposed to the customary steering wheel attendant , should have thought of that before .
toby or not to be worry about your own load 
I should mind my own business.!! 