Tractor hauling accident

[daugen]

good idea about stiffer sidewalls; some sizes hard to find a C rating much less an E tire. I wish TireRack had more choices...

I pull a 31 foot travel trailer with a Blue Ox anti sway bar system installed, conventional 2 5/8 ball. My trailer only weighs a little over 7000 pounds but it's basically a big
shoe box going down the road and is very susceptible to winds and semi "push" . I do the same correction with my steering wheel at times.
It pulls extremely easily with my Ram hemi with the economy rear. But I never pull it over 65mph because I'm afraid of just this kind of disaster
happening. And I get my doors blown off by other rv's speeding past me...
Like windshear to a pilot, you never know what's around the bend. Wind likely had nothing to do with this tractor getting smashed up but if he
was pulling an enclosed trailer the same could have happened.

Most of us pull our tractors so infrequently I would think we could slow it down for those few trips we have to pull at highway speed.
I don't mean to be overly critical here, but too many years in the insurance industry seeing the results
of bad driving.

just how does one know exactly how much weight one is putting on the hitch? I never quite figured out how I was
supposed to calculate that. I don't have truck scales near me.

do the commercial adaptive cruise systems on big rigs include some high tech sway control?

My gut reaction when looking at that picture is someone was going too fast, plain and simple. Speed kills.
If he was going 10mph slower, would this have happened?
I think he was outdriving his equipment, particularly the way it was loaded.
Olympic back seat driving I know, and I have had the you know what scared out of me too
a few times pulling things that started to sway, so i really feel for this guy.
I'd like to ask him if he drives slower now. And moves his tractor mass closer to his truck.

I emailed that link to a friend who is just starting to pull farm equipment on a trailer.
better not to learn the hard way. We've all done that.

 

[Cord]

Since you asked, here's my technique: I typically operate the machinery so I can't tell where the load needs to be placed to provide sufficient tongue weight. My solution is to have the Mrs watch the wheel gap while I slowly drive forward. When she sees the truck squat roughly 2" I know there is enough tongue weight to balance the trailer.

 

[downsizingnow48]

When I towed my tractor from Virginia to California I wanted to be sure about the tongue weight so used one of these:

Sherline Trailer Tongue Weight Scale - Sherline Products

 

[Fallon]

When I towed my tractor from Virginia to California I wanted to be sure about the tongue weight so used one of these:

Sherline Trailer Tongue Weight Scale - Sherline Products

I have one as well. 1sq in piston * psi gauge makes for the gauge reading the correct weight.

 

[JRobyn]

Nice (pricey) hitch adapter with built-in gauge - Facebook

Better link - Weigh-Safe Trailer Hitches - Towing Peace of Mind

 

[daugen]

interesting strain gauges, good idea, love that last hitch.
My truck autolevels so it's hard to tell how much it goes down.

 

[ning]

Re "hitting trailer brakes won't do anything" - trailer brakes will have the same effect as accelerating the truck as far as stability goes. In both cases, the trailer is pulling on the truck, which will stabilize the situation; when the truck is braking (or maintaining speed going down a hill), the trailer is pushing on the truck, and sway will have a bigger effect.

 

[1stDeuce]

My new to me 2013 Silverado has traction control and stability control but did not have a brake controller til I installed it. Manual says stability control is for the trailer sway correction by applying the trade brakes.

Because your truck doesn't have the factory trailer brake controller, it won't do anything with the trailer brakes, but it will still use the vehicle brakes to counter an unstable sway, and it'll clamp it right down. If you had the factory trailer brake controller, it would ALSO apply the trailer brakes fairly aggressively. (Owners manual doesn't get it quite right in this respect...)

Without the factory trailer brake controller, the reaction from the stability system is to apply left and right side brakes of the vehicle out of phase with the yaw/sway, which damps it out, and brings down your speed at the same time.

I'll say again, I wish they would have put a warning in the owners manual that suggests adding tongue weight if this ever happens. We pushed for a message over the DIC to say "Trailer Sway activated" or "Tongue weight tool light", but GM is too stupid to actually make it a useful feature. (They hated using DIC messages at the time...)

 

[1stDeuce]

I know what you're trying to say, but I think you took it a bit too far.

You're right. Tongue weight isn't the ONLY thing, but it IS the main thing. And it is the only thing that will cause a trailer to begin swaying on it's own.

This is probably going to be long, but hopefully informative... Moment of inertia has some to do with it as well. A trailer with the load mostly over the axles (well, a little forward) will be more stable than one with the load spread out toward the ends of the trailer. This is particularly true if the axles are fairly centered under the trailer, resulting in lighter tongue weight. Moving the load toward the ends, and away from the axles is what increases the moment of inertia about the axles. This is exactly the case with Cord's snowmobile trailer, having two sleds in front, and two in back, and relatively centered axles, I'd bet?

As a rule of thumb, as the moment of inertia about the gets higher, so should tongue weight. If Cord's trailer had been built to put more weight on the tongue, he wouldn't have sway issues. Instead, the mfg chose to keep the tongue light so it could be pulled with a 1/2 ton without a weight distributing hitch. In doing so, they gave it a big moment of inertia about the axles. It's generally stable on its own, but if you induce some sway, that big moment of inertia makes it more difficult to get back under control. The sway may even amplify once it starts, depending on the wheelbase and weight of the tow vehicle, stiffness of tires, etc. This is what I'll refer to as "wagging the dog". A friction sway control will help, but it's a band-aid on less than ideal vehicle dynamics.

Some travel trailers are this way too, particularly the ones that advertise "half ton towable". Run away from those, or learn to load them really heavy to the front and use a weight distributing hitch if you're planning to come out west, where speeds are higher, winds are stronger, and semis are doing 80mph... Snowmobile trailers are tough to deal with, as you can't really load the sleds much differently. One of my friends had a sled trailer like this, and we piled luggage, tools, the spare, etc all up front, and slid the sleds forward as far as possible. No more sway, even passing semis, but we had way too much tongue weight for a half ton at that point, and even more than is ideal for a 3/4 ton.

I've seen more than a few snowmobile trailers out west converted to gooseneck. Because the hitch is right over the back axle, or slightly forward, the trailer has no leverage to "wag the dog". That makes a 5th wheel or gooseneck pretty much sway proof, even if you manage to keep the tongue weight. They are much more stable to tow in all conditions than a bumper tow trailer.

We tested a 30' gooseneck with about 5000lbs right at the back of the trailer. (~10k total trailer IIRC) We had about 500lbs pulling UP on the hitch. (We were obviously not on public roads...) ZERO sway. Comparatively, about 350lbs negative tongue weight on a 3500lb trailer will throw a Tahoe right in the ditch at about 30mph.

Someone above mentioned sway on semi trailers... As with goosenecks and 5th wheels, sway is really not an issue with semi trailers. Again, this is largely because the hitch is over the axle of the truck, and to a lesser extend because a semi trailer is almost impossible to load tongue light. With tandem or triple trailers, you can get some "whip" at the rear trailer, but that's not really sway, it's just whip, and a jerky driver or too much cross wind is usually the cause.

 

[sdef]

A couple years ago I was following a guy on a moderately busy two lane highway going downhill a bit slower than the speed limit and I was trying to get around him. He had an older truck with some kind of 60s era car on the trailer. I started to pass just as the trailer started to twitch a little bit. I got back in my lane still behind him and backed off a bit. It started to sway just a little bit and I said to the guy (in my head), better tap those trailer brakes- as I backed off more. My next comment was "!@#$, you are going to lose it... as the rig swayed/jerked between each side of the highway twice and ended with the whole rig on its side in a cloud of dirt in someone's front yard. His load stayed on the trailer so was tied down okay.

The whole event took maybe 25 seconds. I went back to render aid and both persons were out of the truck and said they were ok, with driving cussing about just having gotten the car out of the paint shop... My guess is both drivers of these two events either did not have adequate brakes, did not have the trailer loaded properly or did not know how to control their trailers. Accelerating can straighten a trailer out in some cases but I think braking the trailer is a far better first move and what always has worked for me with a trailer that had brakes. Slowing down has worked also if done soon enough depending upon circumstances. Plus my trailers are always loaded properly.

I know the tongue weight of my trailer and tractor in its "standard" configuration and have marks painted on the trailer deck for where to place the tractor's axles for proper, measured tongue weight and use a Blue Ox WD/sway system. I adjust these load points depending upon various mounted implements.

Note the thin white line on the deck by the tractor's front wheels. I have moved the tractor back a little bit from normal to compensate for the weight of the stump bucket forward of the tractor. Bucket is strapped down out of view and the tractor bucket sitting on top of it and chained down. Weight of ~ 15% - 18% on tongue is my norm.