So what do you do if your gym only has a smith machine and dumbbells? It's dangerous and hard to bench without spotter.
I bench 120kg+ without a spotter (at 95kg body weight). If I were to fail disastrously, I might have a broken rib, but without collars on the bar the chance of a severe failure that cause me to drop the fully loaded bar on my chest is pretty much 0. I've put it down on my chest and rolled it off more than once, and it only causes a light bruise that's gone in a few hours. I probably wouldn't do much more than 1.5 tim…
The first thing is, unless you're not concentrating, you don't really drop it. For me, it's normally not being able to lift the weight back up when I've brought it down to my chest. Without collars, you can just tip the weight to the side, the plates fall off, and the bar (fairly rapidly) pings upright. Makes a bit of a noise, and you feel like a fool, but that's all :-)