Tony
12-08-2009, 11:52 AM
If you've ever wondered how we are able to cram cars onto our trailers without risking damage from bumping together, I'll try to show you now.
The simple answer is to stop motion. Larger car haulers use chains which completely limit motion on the trailer since the frame of the car is tightened toward the trailer decking, compressing the cars suspension. This limits motion in all directions except for some slight side-to-side, but not really noticable.
The smaller carriers, like wedges/flats/steps mostly use wheel straps. The manufacturers do not really explain how to secure a car other than 'around the wheel and down to the tie-down point'. But that is honestly not enough.
I have seen many tie-downs similar to the first picture... which if you think about it, when the truck applies brakes, the car can slightly move laterally towards the other cars. If you think that all of the cars will move in the same direction... you're wrong. They will all move in different amounts resulting in bumping between them. Here comes a damage claim for license brackets, spidered paint on plastic bumpers, or worse.
http://www.autoexpeditor.com/attachment.php?attachmentid=19&stc=1&d=1260295312
http://www.autoexpeditor.com/attachment.php?attachmentid=20&stc=1&d=1260295515
Now considering we do not want these cars to bump each other in transit, the best method is to prevent the cars from moving towards one another. To reduce motion laterally, we need to provide tension in a lateral direction to prevent this motion. For each side of the car, provide tension in the opposite direction.
By preventing as much lateral motion on the cars, we are able to place them closer together on the trailer without causing damage during transport.
http://www.autoexpeditor.com/attachment.php?attachmentid=17&stc=1&d=1260295030
http://www.autoexpeditor.com/attachment.php?attachmentid=18&stc=1&d=1260295169
Did you notice this? I slide my hook through the bottom of the rub rail and hook around. The reason? If for some dumb reason I forget to check my strap and it comes loose... I don't lose a ratchet!
http://www.autoexpeditor.com/attachment.php?attachmentid=21&stc=1&d=1260295853
The simple answer is to stop motion. Larger car haulers use chains which completely limit motion on the trailer since the frame of the car is tightened toward the trailer decking, compressing the cars suspension. This limits motion in all directions except for some slight side-to-side, but not really noticable.
The smaller carriers, like wedges/flats/steps mostly use wheel straps. The manufacturers do not really explain how to secure a car other than 'around the wheel and down to the tie-down point'. But that is honestly not enough.
I have seen many tie-downs similar to the first picture... which if you think about it, when the truck applies brakes, the car can slightly move laterally towards the other cars. If you think that all of the cars will move in the same direction... you're wrong. They will all move in different amounts resulting in bumping between them. Here comes a damage claim for license brackets, spidered paint on plastic bumpers, or worse.
http://www.autoexpeditor.com/attachment.php?attachmentid=19&stc=1&d=1260295312
http://www.autoexpeditor.com/attachment.php?attachmentid=20&stc=1&d=1260295515
Now considering we do not want these cars to bump each other in transit, the best method is to prevent the cars from moving towards one another. To reduce motion laterally, we need to provide tension in a lateral direction to prevent this motion. For each side of the car, provide tension in the opposite direction.
By preventing as much lateral motion on the cars, we are able to place them closer together on the trailer without causing damage during transport.
http://www.autoexpeditor.com/attachment.php?attachmentid=17&stc=1&d=1260295030
http://www.autoexpeditor.com/attachment.php?attachmentid=18&stc=1&d=1260295169
Did you notice this? I slide my hook through the bottom of the rub rail and hook around. The reason? If for some dumb reason I forget to check my strap and it comes loose... I don't lose a ratchet!
http://www.autoexpeditor.com/attachment.php?attachmentid=21&stc=1&d=1260295853