Jackknife!!!

Careful in your turns too. My one and only jackknife was while making a right turn going down hill on a snow covered road. This was in the Army and the truck had a tach box recording speed and it didn't register meaning I was at or below 5mph... unfortunately the trailer decided to go straight and pushed the tractor around on it.

 

The best thing to do is to not drive the truck like you stole it.

That being said, if you catch the jackknife early enough, accelerating out of it and counter-steering is your best option. Any time you lose traction (whether it's ice, snow, a steer tire blowout, etc), the best way to regain it is to accelerate. Hitting the brakes will make it worse, because you'll lock up the wheels and have no steering abilities whatsoever.

 

A jackknife occurs when your trailer tires break traction. Using your trolley brakes just complicates the matter as you are doing nothing to restore traction but aiding the traction loss. The only way to restore traction is to stay off the brakes. Preferably accelerating but usually having to stop quickly is what got you there in the first place. Empty trailers will jackknife much easier and of course wet roads will let you jackknife easier.

Let's say there is no traffic. You can actually control the level of a jack knife by how you brake. But once your trailer gets to a certain point it will force you to lose tractor tire traction which then you lost total control of the situation. Your only hope then is to hope the situation in front of you improves where you can point your steers and accelerate.

I once had a little old lady at the I-95/I-495 DC split change lanes at the split at the last second. She panicked and locked them down in front of me. As I braked hard I watched my trailer start to jack knife and me surrounded by traffic. So it was pretty much brake hard, as the trailer touched the zipper, release brakes, rinse and repeat all in the matter of seconds. Luckily as she disappeared under my hood view she gassed on it and avoided the collision. I had to pull to the shoulder to regain composure. That was back in my rookie days. A situation like that will teach you a lot.

You can't always help it but the best thing to do is to not get in that situation in the first place. Practice good following distance and don't fall into the monkey see monkey do mentality of tailgating. But if you do find your self in that situation you have to watch what's in front of you and your trailer at the same time. If you are going to hit someone try to minimize the damage. Letting your trailer come around and taking four more cars out is not minimizing. If the shoulder is your jackknife side then go ahead and do a controlled jackknife.

If someone runs a red light your swerving ability is limited so try to hit them anywhere but the door to hopefully save their life. You can go from the door to the trunk which might just save them. Slamming on the brakes and holding the wheel straight and hoping is not always the answer. It's good though you are looking at all scenario's. A good driver thinks and tries to find outs.

I can't remember which movie it was. It think it was Dual? or maybe Maximum Overdrive? with the coming down the mountain scene trucks were jackknifing. Of course it's a movie but the stunt drivers were controlling their jackknifes. As professional drivers we can't practice that but only learn through experience.

 

Funny Me, I just slow down and drive with the weather. If dispatch can do better, come show me.

 

Actually most jacknifes occur as a result of the tractor losing traction rather than the trailer.

 

So I grabbed my dispatcher by the neck, It says Kenworth, not aircraft. I would rather be late, than these kind folks loose there goods. They agree.

 

I don't know what part of science it is but think it's physices "an object in "motion will stay in motion unless acted upon by an outside force". I think thats the quote. Two forces are at work in the typical jacknife. A trailer wants to keep going straight and a skidding wheel wants to lead. You lock your drives they want to get to the front the trailer wants to go straight and everything goes to #### in a hurry. Not that I'm an expert by any stretch of the imagination but I've never had a jacknife and I attribute that to luck more than anything. The few instances I've felt the back end getting loose I've simply driven out of it. All instances for me have happened in the snow and or ice. In my opinion all jacknifes are attributable to driver error. Excessive speed not paying attention etc. Case in point in a severe rainstorm in San Antonio a couple days ago a truck exiting onto 410 from 35 lost it. Its an ugly high speed exit he jacknifedand #### near went off the over pass. A fallowing truck ended up jacknifed next to him. The first truck was traveling too fast for the exit back end came loose the second was fallowing too close and jammed his brakes locking up and jacknifed as well. Both were driver error in my opinion. Although the official report will probable say weather related. I was behind both the trucks and watched as it transpired but I was going slow enough and was far enough back to avoid it. As I stated previously luck.