12v electric magnet

[BrianG]

An electromagnet could certainly do what you want, but the power requirements would be a little excessive for what you get. And yes, vehicle momentum will certainly increase the load requirements. You could easily double that weight in motion depending how fast the car stopped in a crash.

Electromagnets are pretty strong to resist pulling them apart, but any slide action and they will release. Just like how a strong fridge magnet works if you try to pull vs slide it.

Where I used to work, they used electromagnets on the doors for security (also had UPS/generator to power them if mains were lost). They were pretty small (around 4" X 4" X 8" ) but you could not force them open. Those operated on 24v DC IIRC, and consumed a few amps just sitting there.

I am having trouble visualizing the application. But I would opt for a mechanical latching solution instead. Then, use a solenoid/servo or something to actuate the release so you still get your "release at the flip of a switch" functionality...

[JThiessen]

Generally when I design a shipping container, I design for a 10G forward load for the part restraint system. This makes certain nothing gives up when that vehicle goes from 70mph to 0mph in a second.
10G is basically 10X the mass of the object - in your case, almost 600 lbs.

[_paralyzed_]

Originally Posted by JThiessen

Generally when I design a shipping container, I design for a 10G forward load for the part restraint system. This makes certain nothing gives up when that vehicle goes from 70mph to 0mph in a second.
10G is basically 10X the mass of the object - in your case, almost 600 lbs.

The dropped floor conversion and lift in my van have it weighing over 9000lbs, and it's a half ton, my brakes take about 2 days to stop from 70mph

The conversion had to be crash tested to be DOT approved but they didn't test stopping distance. My poor e-150 is getting beat up, what'ya do?

It doesn't seem like this will pan out, I need something mechanical as BrianG suggested

[JThiessen]

DOT approvals are a freakin joke IMHO. You can put whatever GVWR on the side of your rig and they will certify them with no logical engineering look at the actual specs of the vehicle. The only time they actually step forward with a voice of authority is when there is a pending lawsuit on something. Sore subject for me...
Yes, a mechanical devise would likely be a better approach, and much easier to accomplish. Can you clamp around the rim of the wheels somehow, without damaging them? I'd almost have to think there should be a commercially available device that one could copy in some fashion.