I have 3 mowers, 3 wheel barrows, bunch of hand tools, power washer and some other stuff that is in my trailer at all times. only thing i did was screw 2x4's to the floor infront the wb wheels, and behind the wheels, and between the front and back wheels. I just bunji all the handtools together (rakes in one bunji, shovels in another, etc). Everything stays intact, which im suprised, im really suprised that the wheels barrows stay intheir place.
I plan on getting some prolockers very soon. No matter what stuff can fly out of the trailer if it was impacted enough, not to mention either killing someone, or even just breaking a bunch of your equipment if it was sliding around. A trailer traveling at 60mph can stop, the stuff inside cant, unless you secure it down. The only thing 2x4's do, atleast from what I can tell, is help it from sliding around, if I had a hard enough impact, for sure it'd come right through the trailer, maybe.