Will the car make it in?

[Taylor]

This is a question I've pondered for a while, and it became reinspired by the airplane-treadmill discussion.

I'm sure we've all seen the movie scene where the sports car is speeding down the freeway, there's a semi truck ahead that lowers a ramp, the car drives up the ramp into the trailer, the door closes and the cops come blowing past.

Is this possible?

I'll leave this open before posting my own thoughts - I wouldn't want to bias anything or anybody.

[Elgin Clock]

Originally Posted by boiler

Is this possible?

Yes, a car can get IN to the truck, but I'm assuming you don't want the car to end up trough the wall and into the cab of the truck right? You want it to STAY in? lol

OK, here we go.

Well, some people know that I suck in physics (taken the class like 4 times and still haven't passed) so.. I'm just going to give a common sense reply.

Assuming you are on a highway and the tractor trailer truck is going 60mph:

If car is going double the speed of the truck, then it won't work because the car will not be able to stop in the truck in time (would have to do 60-0 in about 60ft.. (an average trailer is 53' long + the ramp)

If the car is going 60mph then it won't work as well, cause the car would just be pacing the truck behind it.

But, I think it would work if you are going ~10 mph over the truck's speed, and you will have enough time to go up the ramp and stop before you hit the end of the front of the trailer (behind cab) and it will work.

I think having a front wheel drive car, as opposed to a rear wheel drive car would impact these results differently as well.

If you have a front wheel drive car, those will catch the ramp first, and shoot you in the truck at a different rate, and with more time to slow down than a rear wheel drive car.

If you have front wheel drive, you can get the front wheels on the ramp.. and hit the front brakes, and you will be on the ramp and stopped. but rear wheels will still be rolling off the ramp (on the ground). so.. then you can just use that front wheel drive to go 10mph up the ramp and into the truck.

It would be a lot harder doing it with rear wheel drive, cause as soon as your wheels hit the ramp you are doing 60mph on a static surface (ramp into truck).

I think this would be a good mythbusters episode btw.

OK, so.. anyone want to throw in some "real" physics data to back me up, or strike my theory down?

[RogerR]

i've always assumed that you accelerate to a slightly faster speed than the truck, then put the car in neutral right before you entered the trailer, and coast in, using the breaks as needed.

[Andrew Blair]

I'd say it's definently posible to do, but I wouldn't want to be the guy in the car, or the owner of the car. Reason?

Semi-trailer ramps are steep, and sports cars are low. With some damage to the front of the car and one very rough entry, you could probably make it in.

Other than that, I'd say Elgin's probably got it pretty well down. I hope this won't turn into another "Will the Airplane take off from the treadmill?" thread...

[Cuog]

yes it can be done have u seen the chevy comercials from about a year ago when they had the SSR do it backwards.

And in fear factor teams around the same time they had the driver blidfolded and their partner had to guide them through it. one team did it

and on a smaller scale(I.E. at about 15 mph) i have done the same thing w/ a garden tractor and a utility trailer.

[DonRotolo]

Originally Posted by greencactus3

the 100-0 mph deceleration would be very slow because its ONLY decelerating the rotational inertia. not the whole car's. so with a little rubber mark it should stop easily.

Yes, exactly. The rotational inertia of the two wheels (at a time) is small. The relative speed of the two vehicles is what is important here. Once you hit the ramp, you will have to accelerate to get up the ramp, and stopping once you're in and up will be fairly easy.

Originally Posted by Cuog

and on a smaller scale(I.E. at about 15 mph) i have done the same thing w/ a garden tractor and a utility trailer.

Cool! Why don't YOU live in my neighborhood?

Don

[Cody Carey]

i've always assumed that you accelerate to a slightly faster speed than the truck, then put the car in neutral right before you entered the trailer, and coast in, using the breaks as needed.

I believe that that is exactly right. The pictures of kitt doing it also prove that it is possible, as those are not models

[Jay H 237]

Originally Posted by Andrew Blair

I'd say it's definently posible to do, but I wouldn't want to be the guy in the car, or the owner of the car. Reason?

Semi-trailer ramps are steep, and sports cars are low. With some damage to the front of the car and one very rough entry, you could probably make it in.

Other than that, I'd say Elgin's probably got it pretty well down. I hope this won't turn into another "Will the Airplane take off from the treadmill?" thread...

I agree with what you said, it can be done.

It would also be rough on the drive line of the car, although not as rough as exiting the truck at speed. A sports car isn't a necessity though, it can be done with almost any vehicle.

Also don't forget that as soon as the car hits the ramp it will lose some momentum due to the upward angle of the ramp, not enough to stop but it will slow down and if you hit the brakes you should be able to stop in the trailer whether it's a 53' or even a 48'.

Most of these regular trailers have an oak floor so you can scab cargo in except for the steel plate in the front over the king pin. Other trailers have an aluminum floor. Then there's also some that the floor is completely covered in rollers, not the type of trailer to pull this stunt with. They do make trailers with low loading heights, not dock height, for enclosed car hauling. These trailers are specifically meant to accomodate different vehicles, similar to this, but I don't think this is the type of trailer you meant for this experiment.

[Bill_Hancoc]

Sure it can be done at a slow speed but at above the speed that you can stop in 60ft it would be essentialy impossible. even with a front wheel drive car you would still be going whatever speed in relation to the truck and no longer to the ground. and when you braked you would be braking the back wheels too and there for almost pulling yourself off the trailer.

[lukevanoort]

I'd say you could do it. My vehicle for it? Some jeep. Lots of ground clearance, not too wide. But, if you screw up... well, that jeep will not be in as good shape as, say, a Corvette. Approach at about 7 mph faster and switch to fwd mode (I assume Jeeps can, I don't know) when the ramp is hit, and drop the rpms. The second the rear wheels are on, brake. It might work. (esp. with aftermarket brakes)

[greencactus3]

Originally Posted by lukevanoort

I'd say you could do it. My vehicle for it? Some jeep. Lots of ground clearance, not too wide. But, if you screw up... well, that jeep will not be in as good shape as, say, a Corvette. Approach at about 7 mph faster and switch to fwd mode (I assume Jeeps can, I don't know) when the ramp is hit, and drop the rpms. The second the rear wheels are on, brake. It might work. (esp. with aftermarket brakes)

eh... i disagree. first off a stock jeep wont switch to fwd. and noone i know would ever modify their jeep to do that.
id go with a rwd. roll the front up thats easy enough. and then just go 1mph faster than the trailer and roll up. even if the car is going 101 and the trailer 100, the 100-0 mph deceleration would be very slow because its ONLY decelerating the rotational inertia. not the whole car's. so with a little rubber mark it should stop easily. its prolly harder to do in fwds like minis tho.
stick a linelock in there and mightbe easier. or if its slower speeds go in reverse and parking brake.

[Mike Schroeder]

Should probobly just ask KITT

[Elgin Clock]

Originally Posted by Big Mike

Should probobly just ask KITT

I was waiting for that reference... LOL

[lukevanoort]

Originally Posted by greencactus3

eh... i disagree. first off a stock jeep wont switch to fwd. and noone i know would ever modify their jeep to do that.
id go with a rwd. roll the front up thats easy enough. and then just go 1mph faster than the trailer and roll up. even if the car is going 101 and the trailer 100, the 100-0 mph deceleration would be very slow because its ONLY decelerating the rotational inertia. not the whole car's. so with a little rubber mark it should stop easily. its prolly harder to do in fwds like minis tho.
stick a linelock in there and mightbe easier. or if its slower speeds go in reverse and parking brake.

Okay, I didn't know that. I just know some 4WD vehicles can, and the jeep seems like a good fit in other manners. Now that I think about it more, how about a motorcycle? Be pretty easy in that I'd think.

[greencactus3]

Originally Posted by lukevanoort

Okay, I didn't know that. I just know some 4WD vehicles can, and the jeep seems like a good fit in other manners. Now that I think about it more, how about a motorcycle? Be pretty easy in that I'd think.

now that i think about it, jeeps are fine if you have a winch. neutral, and winch it in. apply brakes as needed