Referencing Nathan Vanderslice's comment about pulling equipment into a van...
Here's what I did for awhile; the amp rack weighed about 400 lbs and sometimes I was the only one available to work a show. The winch is has a 1000 lb capacity and was run from the van battery. It worked great... then I realized, "what the hell am I doing?" I sold off the amps (Crown, Crest, Peavey) and went all QSC PLX. The rack now weighs about 200 lbs and I don't need to the winch. ---> If you can avoid having to load your vehicle this way, by all means... don't do it. Too much room for error and potential injury.
Pay no attention to the "see through" lights on the wall - those belonged to a band that I mixed for on a regular basis - they gave me a "little more $" to store their lighting and some of their sound.
There are only a few hazards here and if properly done, they can be all but eliminated.
1 Make sure that your anchor point for the B&T is something solid, that is a part of the vehicle.
2 Make sure that your cases/carts are properly loaded so that the heaviest stuff is on the bottom.
3 Make sure that open cases/carts are not overloaded, that is, packed so full that stuff is falling out of them.
4 The pulling point of the cart/rack should be somewhere below it's midpoint. This helps assure that you don't tip it over if a wheel snags, and does enough to keep it from tipping over when pulling it up the ramp, especially if the ramp has a steep leading edge.
5 Try as best as possible to load where you are on level ground from side to side, if that's not possible, have someone on the low side to make sure that the cart/rack doesn't tip over. Not hard to do if the movement is stopped before it goes too far.
6 Periodically check the condition of the equipment (ramp, B&T, winch) and make necessary repairs ASAP.
I know this sounds like I may be talking down to some of you, but it's amazing how many people overlook these simple steps, especially the last one. The last thing you need, especially if you are by yourself, is to get seriously hurt during setup. If you need help, hire someone even if it's only once, or make arrangements with the client to provide some help. It doesn't necessarily need to be someone really strong. Again, if something starts tipping over, catching it right at the beginning is the key. One last thought is that if something's going over, you have to know when to let it go and keep yourself safe. Your own safety and health are far more important than any equipment you have.