Towing story (long) - grossin' 17k+ (accident)

[fordnut85]

Surge brakes SUCK!!! Glad everyone is OK, could have gotten REALLY bad REALLY quick.

As was stated before, a quick grab of the trailer controller would have fixed that problem.

[Tex5String]

It's the pendulum effect when the center of gravity of the load is behind the trailer axle(or the centerline of tandem axles). If the load moves to the right because of wind or the draft of a passing truck , the tongue and hitch go left, pushing the flexible combination of tires(sidewall flex) and suspension of the tow vehicle to the left.
Now with the hitch moved to the left, the trailer oversteers to the left with the weight acting like the rudder on a boat, so after a second or two, the load is tracking too far to the left, pushing the hitch to the right. The trailer travels farther out of line each time because of trailer suspension and tire-sidewall flex.
This may be one reason the big rigs have the axles at the rear of the trailer: no way to the get the center of gravity of the load behind that location.

I am always careful when loading horses to get the big one in the front end of my stock trailer and the lighter one behind the axles.