Wind

Ok Hammer I take your point, but as a student who just plain doesnt know through own experience he did the right thing. And from the trainers point , student with no experience was driving. so...they eithe were able to get the load late or not. They are still upright and ready for whatever load they are given.

I like that we are seeing some encouragement in the responses from those with exp. What other good exp info can he be given to make a decision for himself when he goes solo? your post above is very helpful.

 

Yeah, Mickeyrat; I wasn't faulting the student, but the trainer. The trainer should have better thought through the decision to stop, as those kinds of decisions are important for the noobs to learn. It would have taken 5 minutes to pull out the map and explain as I did up there^ that the risk was greatly reduced from that point on. I'm all for stopping if you feel conditions are unsafe, but this was a definite failure-to-teach moment.

 

Actually, going back to the comments cross posted from Otter earlier. If they were that close, it would be nothing to pullover and slide the tandems back to help keep the weight to the rear. That's maybe a 3 minute stop.

As far as gusting vs. non-gusting, my rule of thumb, consistent winds above 25 mph I will park, or greatly reduce my speed, gusts above 30 mph I will no play in. I've been blown over once, earlier in the day it had been a High Wind Advisory, they lifted it completely, I came through in consistent 20mph winds, tandems halfway back, and about 55 mph. Freak gust of wind lifted the container off the chassis (front pins had vibrated open), twisted the chassis to the point the left sidewalls were rubbing on the pavement, then the rear pins sheared off, and the container slid into the median. I stayed upright, but learned a lesson that day. Last summer, I had another one lift off the front pins, I was able to jam on the brakes and head off the road before it came off completely. CSP saw it happen, though for sure I was a goner, 1 ton wrecker was able to winch the container back on the chassis, I triple secured those front pins.

I do not play with crosswinds, I will park it, snow, ice, rain, I'm fine, but wind is one thing I will not play with.

 

I've only stopped for winds twice in recent memory. Once was in Arizona when the highway patrol shut down 40 between flagstaff and Winslow due to high winds and blowing dust and in Lemitar, NM when the winds blowing across 25 were a sustained 45-50 mph with gusts approaching 65. I was heading home empty from the Los Lunas Walmart DC.

Dispatch warned me it was getting bad so they were cool with me stopping. Wind didn't die off until 3 in the morning.

Ironically it was the same storm that shut me down in Arizona.

 

Dammm, striker. Glad you kept the rig upright, and came out unhurt, even tho it laid out your container. Not to mention episode #2.
Error in your wording on sliding the tandems, but I'm sure you meant more weight on the drives, not trailer tandems.
If the tandems are slid back, we know that adds more weight to the drives, and less on the trailer's.

But the idea behind moving the tandems back for the purpose of reducing wind effect, has nothing to do with weight transfer.
It has to do with two other main things. That is, moving the "pivot point", which is the tandem's centerline (in relation to their position on the trailer) rearward, so that the rear overhang (if tandems were forward) doesn't create a "leverage point" for the wind gusts. Not easy to explain.

Lemme try to clarify...
The reasoning behind it requires thinking of the "mounting points" (kingpin & trailer's tire to ground contact point) and not any load transfer.
If you have your tandems all the way back, any wind force will be pushing a relatively equal force against the whole side of the trailer, but will be resisted at these two "mounting points". This will make the fifth wheel (kingpin) and trailer tires carry equal side load, thus not trying to "pivot" the trailer on it's tandems.

If you have the trailer's tandems far forward, then a side-wind gust will also be exerting force on the overhang portion of the trailer, and try to pivot the trailer on its tandems.
In other words, a heavy gust of wind from your right side could actually be trying to force the kingpin ALSO to the right side, due to trailer pivoting on the trailer's tandems, if the rear overhang portion caught a heavy wind gust.
The overhang also creates a rear lift point, which wouldn't be the case if the tandems were slid all the way back.

Note: These type of physics are harder to explain, without having a drawing or toy model to demonstrate with.

 

I've done a lot of 3k loads to the nortewest, summer and winter.
I watch for wind socks i.e. plastic bags stuck on the fence lines, smoke from plants, businesses, chimneys, etc.
I've only taken route 30 from Laramie to Rawlins twice due to the wind and both times in the winter.
Light touch on the steering wheel, small corrections/movement, traction determines speed/braking efficiency.
Empty eastbound at Rawlins, gusts to 50+, but at my back. Rolled on to Laramie. Road surface conditions determine safe speed.
Check the mirrors constantly. Operate between the lines in your lane or stop somewhere.

Don't set your trailer brakes below freezing temps. Check your mirrors, especially when you start rolling.
Down grades, watch your trailer tandems and look for smoke(Brake fire coming). Pull over or burn it up.
Climbing gear going up, maybe one gear lower when you head on to the downgrade. Save your brakes, save your truck.

 

Good point about heading south with now a tailwind...but like the pladitude, "you can turn 4 different directions in IA, and still have a headwind."

Most hyways, if viewed from the air, meander several degrees left and right, and some almost turn 90 degrees at times, even out in the big states. And as stated, it is the gust coming from nowhere that will get you.

With the hp that most have today, wind is not the issue it was when one had a tiny little 2-stroke Detroit. I remember very well driving out west with a 13 speed and a big tailwind, and the road would turn slightly left of right, and have to drop 2 gears! I was in IL one time, and could only go 35 mph on the interstate with an empty 45. Pedal flat on the floor....

But, overall, the tailwind should have been 80% better.....

 

KWCajun, I understand the principle of how it works, an old timer coworker (supposedly got his CDL shortly after they invented the wheel......RIP Mr. Houston) explained it to me.


Was supposed to go to Casper this morning for a pu, crawled out of bed at 2:30 am, checked www.wyoroad.info, didn't like what it had to say, went back to bed for another hour. Slithered into work at 5:15, boss came in about 5:40. Explained it him, he found something else for me to do, which was a good thing, since they later closed the road to empties, 65+ mph gusts.