Near jacknife in rain

Oh I used to have one of those QCs that called home to mommy when I hard braked. Had an event once while bobtail. Got that call from safety. Those things, all those radars and other things and those rearward facing camera's is why i am so glad I am out of trucking.

 

I was not sure it might come across as saying you're wrong or did not know a possible answer. That how this social media stuff seems to go a lot.

I said people can step on the throttle and pull the trailer back behind them and then try slowing down. It not something a lot of driver think about. Especially when you need to stop. I had the same thing happen to me. Stopping for red light. Trailer was sliding to all the parked cars on side of road. Only option was step on throttle and hope I could get trailer under control and try stopping for red light again.

 

Oh yes...the i shift or auto shift (whatever you want to call it) have done some devious things to me.Like you said basically"grabbing a lower gear Suddenly for no apparent reason,or like happened to me about a Year ago. 24° Foggy,road Wet ( Think fils of ice occasionally...Going down Blewett Pass (Wenatchee)...Takin it really Easy...SOB startted kickin up shifts .Whoa! Had to go in "Maual Mode" to keep from running too fast down the grade.They can be "really handy" though ...sitting in traffic.

 

Dont Forget...About the Weekly "Report Cards".Lol

 

My auto shift is rarely out of manual mode. Thanks for reminding me why.

It's not hard to spin 'em on wet roads when empty. Or to slide if trying to stop too quick.

 

I have had that trailer come round. But my first tractor jackknife was in a COE and it was very violent I got out of that one but all crooked at that intersection in question. Spent oh a hour questioning my desire to stay in the industry. Shook for like two days. But like a horse, you get back up there. Find a way to get along. Or stay off it forever.

My third with the ex on small ice west of knoxville was a bad day. Ex was driving so it made it her first. And she froze. Well... I adjusted the wheel for her felt the drives bite and told her to freeze some more like a statue with that right foot as the transmission worked on gearing and settled. However number two spun in that spot got it back but three through seven went into the median which was a wide canyon. One in particular a flatbedder with tarped machinery or something using his power spinning his drives to hold the whole thing straight as he fell backwards into the ravine ... totally against everything we are taught btw but in that specific situation, what he did was good for the load. To heck with everything else. So props to him, whoever it was.

The favorite thing I do every winter with a semi is to find a few acre lot, no light posts, bumpers or anything on that pavement, ice and snow. Work on a circle both ways bobtail then do a figure 8 both ways, when I have total control of that thing sliding and going where i want it to (Sort of.. you can aim it that way...) then you are ready for whatever happens out there.

There is a third form of jackknifing that I did not have to solve and that's on a curving steep downgrade coal road in PA, the trailer in the rain loaded was shoving on my 5th wheel enough to slide my drives on every curve I took. First left, then right then left and left etc. all the way down. It kept hammering against the 5th wheel at a angle trying to spin me to fold.

I managed to go ahead and get on the trolley to stretch it out against my instincts and apply enough service to knock it down three gears until I got her settled against the redline in 4th low. The trailer quit beating on the tractor trying to jackknife it at that point. But she tried to kick her tandems out twice with that trolley applied.

I traced the original trailer behavior to the jacobs brake surging between lugging and redline causing the tractor to become a bounce house and force me out of that one gear. Since there was no traffic whatsoever I went down to about 16 or so and a gear that settled the jake against the redline until we got off that cursed mountain.

I never did use that road again. It's up west of Scranton and frankly there was no call to put a truck on that one.

 

You can jackknife at 5 MPH if you have little traction.

 

Your video did good. I think I saw just a smidgen of that slide to the right with the nose then the whole thing wanting to go left.

I think right there is where your foot came clean off the throttle.

I don't know what the temperature was in the video but I would want to take a look at your drives and see if they already been through a year with you prior to this winter. Maybe ask for a new suit of 10 tires so you don't slide out that easy next time.

 

There are others who have commented on the mechanics, but I'll say my piece.

No matter what kind of tires you have, or how new they are, the amount of friction they can generate is limited.

The weight of your truck (gravity), the type, inflation level, and condition of your tires and the condition f the road surface all contribute to how much friction you generate.

Now, as you are driving, as long as the amount of friction you generate is greater than the total force applied to the tire surface, parallel to the road, your tires will maintain traction.

Forces that can add to the force action against friction are (and I might be missing some): Throttle acceleration, slowing with brakes or jakes, centrifugal force in a curve, wind acting against the truck, bumps or objects on the road, or objects impacting the truck.

Both the friction your truck generates and the opposing forces CONSTANTLY change as you drive.

If the forces acting on any tire ever exceeds the friction that tire is generating, that tire will break free of the road surface. Once ONE tire breaks loose, MORE force is immediately generated against all the other tires, immediately, and additional tires might suddenly break loose as well. For every additional tire breaking loose, the other tires take on more and more force acting against the friction holding them to the road, and you might very quickly break every tire loose, and start to slide.

What happened to you was that at least one of your tires generated more force against it than it had friction, and it broke loose. From the motion of the truck I suspect it was the right steer. I'm pretty sure your left steer also broke loose immediately after the right did, but I don't think any of your drives broke free.

You were in wet weather, on a curve, and you were tight onto the white line as well. I saw the remnants of plow snow piles on the shoulder. Plows both generate and concentrate fine loose gravel and/or sand from either/or sanding or scraping the pavement, and sometimes those piles, as they melt, collapse towards the roadway. As close as you seemed to be to the white line, it is possible that you hit a significant pile of loose sand/dirt mixed with a bit of ice, and that, in addition to the curve, and wet pavement, caused you to break loose.

It's also possible that you might have passed over a place on the road where there was a recent oil leak after a wreck or vehicle failure. Oil and water on the road together can be just as bad as black ice.

It could also be that there was a very slight depression in the roadside and you hit a pool of water and hydroplaned one of your steers.

45-48 mph in those conditions, (from what I could see) wasn't excessive, but I might have been a bit slower. The only other driving suggestion I feel comfortable making here, since I wasn't in the truck, is that it seems like you were crowding the inside curve.

Crowding curves is generally a bad idea unless you have to, even in the rightmost lane, because that's where most of the road trash ends up and you can damage tires on the trash. Stay closer to the center of the lane. If you get used to staying far right in a lane, especially on curves that bear right, you might find yourself in a lane other than the rightmost lane, and accidentally crowding another driver hard enough that you might cause a wreck. Remember, when you are on a curve like that, and your right steer is on the line, your right trailer tires are a few inches OVER that line due to off-tracking.

If I've mis-said anything, I'm sure other experienced drivers will poke at me, but I think everything I have said here is accurate, and might help you better assess how your drive in poor conditions. This isn't me being a pompous ###, it's me trying to offer advice that you can take or leave as you wish.