Jackknifing
 

Hi, I'm sure alll you experinced drivers have a interesting story to tell concerning this topic...I hope you can mention for beginners your methods used to prevent and control jackknifing.

Thanks

Just like a car, go easy on the gas, easy on the brakes, leave alot of following distance and watch your speed. In other words, keep your tires from spinning and keep them from locking up. Its alot easier to prevent a jacknife then save one. If you do jacknife then good luck! In most cases its because of over braking, but the brakes would have been applied for a reason so you probably need them, so letting off is a different problem, oh boy, see what I mean? A jacknife can be saved but you need alot of room which you usually wont have. Its usually going to take letting off the brakes and clutching so all wheels can rotate freely, and in some cases a little throttle, of course you steer into it, but when that trailer corrects its going to have a big head of steam going the other way! Saving it may not be humanly possible so its best to learn to avoid it.


If that doesnt work, take a couple bungee cords and hook one end to the side of the trailer and the other to the side of the tractor and repeat for the other side. :wink:

A jackknife can be saved but like Snowman said, you want to make sure you never have to find out if you have the ability to save it or not. I have seen one that was saved, only because the driver knew it was gonna happen before it actually started happening. He felt it starting to go and was already getting himself ahead of the trailer. Sometimes you can outrun the trailer(in an ungoverned truck of course) and pull it back straight behind you but you need the room to get on the hammer and stay on it till it comes back behind you. The worst you can do is to hit the brakes, unless you want to get the trailer jackknifed around to you faster. Best bet, drive like Snowman said so as to not have to jam on the brakes or be mashing the throttle. If you have hit black ice and that causes you to start the jackknife, your pretty much toast right off the bat if you don't feel it right away and get off the throttle and into neutral so your wheels are free wheeling.

Had it happen to me pulling a set of wiggle wagons down a steep grade. Was just moseying on along stab-breaking my way down when lo and behold I see that rear kite looming sideways in my westcoast mirror. Holy $#$! What did I do? About the only thing I could...stepped on the gas going downhill!!! Slowly but surely, the set straightens out but now I've got another problem on my hands because at the bottom of the hill is a busy intersection with a light. Can't jam on the brakes and I can't slow down! Luckily, heaven smiled down upon me and I caught a green light with no cars backed up. Laid on my airhorn and just sailed right on through!!!

That sure was a close call! I always avoid that hill now and take an alternate route if I've got a set or a pup on my back. Found out later that 20 years ago, a guy lost his breaks flying down that hill with +90K gross in the box and 2 logbooks under his seat. Killed about 5 people and ended up doing a long stretch in the can.

The city tried to ban big rigs from that hill but they got sued by some trucking companies because it was a state route.

I have no first hand experience of this, but I have heard that braking of trailer only may help get it back behind you. :shock:

Is this acceptable practice, should the occasion arise?

Creek

Maybe! Ha ha! Anything that works is acceptable. The reality is that its a feel thing. And the odds are against you. Trailer brakes handles are slow to react and when they do they tend to grab hard. They're also becoming obsolete in later models. Used perfectly for the situation it could be just the ticket but without alot of practice it would probably make things worse. Any jacknife caused by overbraking means you probably have no where to go so its a lose lose situation. If it was caused by your drives spinning then you have a chance if you detect it in time, just let off the gas.

In the old days, this was called "getting her straightened out"....but these days the 'modern' experts say No don't do it- it's also the #1 reason besides cost- that companies don't equip their tractors with them. I've been sucessful several times using this method. But you have to be understand....once the trailer is 15% out of line- you're not going to get it back. And if you use it- improperly you can actually CAUSE a jackknife with it. It should only be used on level-straight pavement or a gentle decline. If used on sloped/curved/banked it usually makes the problem worse.
When you do use it--you have to use the pedal too and smoothly try to pull ahead of it.....this means you'll need open pavement ahead. This is where the rub comes.....(1) you're probably in the jackknife because you're trying to STOP, (2) by the time you start to "feel" it coming around.....it's probably already too late.
(3) you're probably not on straight pavement without traffic spun out ahead.

Oh, P.S. You don't need a "ungoverned" truck to outrun your trailer in a jackknife. If you're driving 65 or 68(full speed-bumping the governor) in ICY winter weather.....you're not going have time to even see your life flash before your eyes...much less time to "try" to save a jackknifing rig..you're just fixing to have a hell of wild ride- and if lucky you'll wake up in the hospital.

And this thread is in the wrong forum.

The closest I've came to having my trailer pass me up was last winter.

I was heading across US 30 in PA between Latrobe & State College. The roads were bad and I was praying to see a place to pull over and sit it out. Well, that didn't happen...

I started down one of the mountains when the traffic ahead of me was at a dead stop. I was only going 10-15mph at the time. When I hit the brakes, that's when the trailer decided to break loose. I got off the brakes, trailer straightened, back on the brakes, broke loose again. I was coming up on the stopped cars pretty quick with my only outs being a deep ditch on the left, hit the cars in front of me or try the strength of the guardrail. I grabbed the trailer brake lever and worked it without touching the pedals on the tractor. Somehow I managed to get it stopped - with about 1 foot of clearance in front of me and the trailer directly behind me.

When I got to the bottom of the mountain I pulled off the side of the road and just "shook" for about 30 minutes.

One good thing (I guess) - the cars behind me stopped tailgating after that.

I do have first hand experience with a "Jackknife", fortunatly the jackknife lost.

I was east bound on 1-94 just outside of and approaching Chicago, it was very early morning around 0100-0200 or so. Loaded with about 22000lbs in the trailer. It was a warm spring night on straight and level ground, however it was raining. Traffic was very light with only a few 4wheelers near me. The rain was "pooling" on the road. I was at about 50mph. Any 4wheelers that were near me had cleared me and I was basically alone. I was in the center lane of 3.
I felt a pull in the seat of my pants and looked out the mirror and saw the trailer on its way around past the 15 degree point. You really have no time to thing about whats happening and you mostly just react to the situation. I did not steer into the trailer but opposite it, it was swinging right and I steered left until the pull I was feeling went away, this kept the tractor and trailer inline, however, it created a new problem. I was going down the road inline, but sideways. The initial correction was naturally overcorrected and the trailer begun swinging to the left, again I could feel this in the seat of my pants. I countersteered back to the right, again keeping the tractor and trailer inline, but still going down the highway sideways. The ossilations continued but dampining with each correction. I am guessing 4-5 swings and corrections and it was over. When the dust settled I was in the hammer lane, didnt hit anything or damage anything. (With the exemption of my shorts). I did not use any braking during the swings. (Service or Trolley).
If any of the 4wheels had been along side me during the swings, they would have beeen "swatted" off the highway.
To this day the real cause is still speculation, however, I strongly believe the trailer tires hydroplaned on the "pooling" water. The tractor never lost traction.
When the tires hydroplane they are still spinning but all contact with the road service is lost. No traction. Pulling the trolley brake would have "locked" the trailer wheels, probably making the trailer uncontrollable.
Since that day I have had a much greater respect toward a combination vehicle and how susptable it is to upset.

I cant say this technique would work in every situation, I got very fortunate that the outcome was favorable, and an amazing learning expierence.

Regarding a governed truck. If you are on surface conditions that could induce loss of traction, stay well below the governer so you have some power available that may allow you to accelerate out of a Jackknife.

Kinda makes you believe in Guardian Angels don't it. You were very very lucky....

I had a slight jacknife while empty on a rain slicked road 2 years ago. I was stopping for a redlight on a cruve with slight banking going down to my left. When I was nearly stopped, I heard an odd noise, like grinding. Looked in my mirror and could barely makeout that the trailer was sliding into the next lane. Let off my brakes and tried stopping again only for the tires to lock up on the trailer and start it coming around again. Luckily, nobody else was around at the time.

head, I was talking about outrunning the trailer if you have a full load behind you and it starts shoving you down a hill to where the trailer tries to pass you. Can happen in prefectly good weather, if your already running at the governor when it starts shoving you and coming around on you, you ain't outrunning it.

Jackknifing
 

Interesting stories guys..keep them coming....it could help a lot of beginners, especially when they hit the mountains.

Canada

Well as long as we're telling stories, there was this one time. I drive a single axle daycab with a set of doubles. When your empty, traction is just a distant memory.I was crusing home 55-60 mph at daybreak, empties, cold crisp morning, no precipitation but real cold. No reason to worry but as a precaution I tend to lift off the throttle on bridges. Well I hit this bridge and quicker then you can snap your fingers my tractor was sideways. I had lifted too much and the engine locked up the drives and I dont even have a jake break! I'd like to say I saved it, I immediately clutched and steered into it, but the truth is the bridge was so short it was over as fast as it started. I hit the dry pavement and it all straightend out, after nearly shaking those pups right off!

Do trailers have anti-lock brakes?

Mine says it does on the sticker on the side of the trailer, yet I can still lock the trailer tires with ease. 8)

I think all new trailers have anti-lock brakes - the key word being "think". All of the trailers at my company, except for 3 or 4 old ones, have anti-lock brakes. Whether they work or not is a completely different story.

My truck has ABS, but they don't work. The wiring harness for the ABS is bad and they don't want to spend the $800+ to replace it. So, I have normal braking on the tractor.

NONONO- you have already lost traction to the trailer, applying its brakes now will only insure that you wont at all...

Along the lines of what CFM said, know a Walmart driver who was running out of Maine empty in the winter. Had a driver behind him calling on the CB to let him know he was jackknifing at 45 mph. A gust of wind had blown his trailer out from behind him while he was crossing an area that had ice on the road. All he could do was hold his speed and let it come back on it's own.

Had it happen twice in one night the first year I was driving.
I had a cabover Pete and a 53 foot Reefer with 2 pallets in the nose. Going across South Dakota toward Rapid City. Lost traction on the tractor and it spun out from under the trailer.

What I did both times besides crap myself was.
Pushed in the clutch immediately and steered like my life depended on it.. Each time I saw the trailer in my mirror coming at me I just sawed the wheel as fast as possible the opposite way.

Probably went from side to side a total of 4 times each occasion. Left Right , Left Right. I am just turning that wheel in a blur , all the while whith my foot mashing the clutch to the floor. Didnt even have time to take it out of gear was not about to take my hand off the wheel.

Just mash turn turn turn turn , "holy crap I did it" :im not in a ditch" "im gonna stop next off ramp" . ......... "damn wheres the next town?" " Wow there isnt anything out here" ...... HOLY @#$% its doing it again" .

LOL.

Ok, here's my Jackknife Experience( which I didn't win )

Scene: Eastern Slope of La Veta Pass, Co (9413ft)
Date: April 15th, 1995


I had just picked up a load of potatoes out of Blanca, Co headed for Florida.
I had also just concluded my 2nd Winter of driving, and just 2 weeks earlier
had unloaded all my "winter" tools/equipment. These were the days before
qual-com and only the rich businessmen could afford cell phones. I had a new "dispatch" which I hated...was a smart-ass kid just out of school...and when I would be making a "check call" and tell him something like...."I'M on
I-71 mm 36 Ohio at the rest area." I'd get back something like...."I don't thank so..are you sure....there's no hwy 71 in Ohio" well anyway, it was Saturday...and on Saturday's they left out of the office at Noon.. It took longer to get loaded than I had planned and a "winter storm " was blowing in...I wanted to make it over the pass before I got snowed in on this side of the pass. And I wanted to make it to "our chance" truck stop before Noon so I could give the Prick his "loaded call".

So #1 mistake: I was in a hurry

I started up the western slope and it was just wet, all the truckers coming down the mountain reported just wet roads on the CB. I think I passed 4-5 trucks going UP the mountain with my 44,000 of potatoes on slipsheets. I was driving a T-800 KW with super10, no bells or whistles at all...just a foot brake and gears. I had just unloaded my thermometer I kept "taped to the west coast mirror" so I'd know exactly when the temp was dropping.....not that the freezing rain didn't usually give it away.

I topped the pass at about 60mph, and started down the eastern slope S-curves( 15 years ago- you had 2lanes coming up-1 going down)
I got 1/3 of the way down just fine- the roads were just "wet" like the other drivers had reported 20 minutes earlier.<<<< Mistake #2 ---Conditions change rapidly at high altitude.

I started around another set of the S-curves(well banked--I might add) when what to my shocked eyes should appear before me! The prettiest blanket of fresh powder that had been blowing in down below right around the exposed curve of the switchback. Here at that section of the mountain..the wind was blowing up the canyon and I knew that under that
fresh powder was a sheet of ice. I still had about 50 yards in front of me--1 more switchback before I'd reach the edge of that "frozen section"...I looked at my speedometer---it read 60mph.....I knew I was
@#$%$%#! I got on the brakes hard.......and got 'er down to 45 as my I
reached the White pavement and let off the brakes....I was probably as white as a ghost.....I was giving my mirrors a quick glance..and we were doing fine...at first....but as soon as I reached the "banked" part of those curves....the trailer started sliding that way.....I corrected....but that put me in the center lane-westbound lane) which I was coming up on a blind curve- I pulled 'er back over in my lane and knew I had to do something...the next curve was 45mph curve...and now I was back up to about 50mph and there wasn't any real estate to the right of me. I straddled the zipper and started praying there wasn't anyone coming UP that Hill....and sure enough as I eased down on the brake..that and the banked slope of that curve started her back toward the ABYSS( canyon below) I straighened her out again(over corrected- in the next switchback---trailer went back across the lane-- I over corrected again...and this time I got my right tires just off the pavement-----but it was just loose sand......leading up the the guard rail......which I plowed down 8 foot of before jacking the tractor/trailer and coming to stop with my driver door and front of trailer hanging over the edge of the cliff.

By the time the trooper got there----the sun had came out--all the ice/snow was completely gone and there were 0 skid marks---except for the trench I dug right up to the start of that guard rail.

One of the wooden post of that guard rail splintered and took out my passenger finder and punctured my fuel tank...I seperated the sleeper from the cab, and crushed the exhaust stack into the trailer.
And that load of potatoes were very messed up!

This method has worked for me on slick hills where there was clay mud that was wet, or snowy. just ease down the hand spike and use enough pressure to get it straight. Sometimes it is necesary to not lock the trailer brakes up, but to just add some drag to get the job done.

All of the older drivers I have talked to have said to leave the trolley handle(trailer brakes only) alone when the trailer starts swapping ends on you. Instead, they say to mash the throttle if conditions allow and yank it back behind you. Yes, you can use the trolley handle but it is very risky, especially for a rookie to be doing it. If your trailer is already beside you, using the trailer brakes ain't going to do anything to help you.

Yeah.. some times even stupid things work out right.

When I would pull triples to SLC from Reno, they would "slide" a lot. I just never looked out my mirrors much and if they started to get sideways, just "spike" the hand-valve (not all the way down) while accelerating. Sometimes it works, sometimes it doesn't...Spent more than a few winters on I-80 on OT waiting for a wrecker...Usually if it got bad enough, we'd ditch the third box. Or hang a single chain on opposing axles on the last two trailers. It was funny though whenever a UPS driver lost a trailer the first on the scene would be a UPS supervisor with a can of spray paint, painting out the company name. Like someone REALLY didn't know it was a Buster Brown truck ???......I also found that talking to myself helps immensely "straighten out damn-it STRAIGHTEN OUT NOW ! OH SH--!!