How to control sway after it starts?

sharps45

Petty Officer 2nd Class
Joined
May 13, 2007
Messages
135
On the way back from the lake today, I ended up having to tow a small boat home behind my camp trailer (due to breakdown in original tow vehicle). My camp trailer has the hitch and wiring installed, so I agreed to do it. Any speed over 45 mph the swaying started, and once when caught by a gust of wind, I nearly lost the boat. It was swaying badly, pulling my trailer, and nearly tipped over. (Because of the circumstances, there was no way to match the trailer and tongue the way it should be, and they weren't as level as I'd like) My question is, once you get a good sway going, almost to the point of losing control, what is the best way to get it stopped? Slowing gradually didn't seem to help, nor did stopping with the brakes. I'd like to know in case this ever comes up for me or anyone else out there.
So come on experts, let me know what to do in this situation. thanks
 

Seon

Petty Officer 1st Class
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Apr 23, 2008
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Re: How to control sway after it starts?

So you were towing a camp trailer and a boat behind that? In most if not all states, it's against the law to "double" tow unless the 1'st tow has a 5th wheel/gooseneck hitch. As to your question, normally on a single tow, slowing the speed usually stops or minimize the sway.
 

Gary H NC

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Re: How to control sway after it starts?

If the sway was getting to the point of wrecking or turning over it should have been stopped and not driven!:eek:
What exactly were you driving and towing? I know better than to ask if these vehicles had brakes....
 

BigB9000

Lieutenant Junior Grade
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Dec 5, 2007
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Re: How to control sway after it starts?

towing 2 trailers, that was the problem, the 1st trailer probably stated moving around a little bit (no big deal) then just transformed to the other trailer 10X

usually not a good idea
 

cdoliver

Petty Officer 1st Class
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Mar 18, 2008
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Re: How to control sway after it starts?

The answer is to floor it until the sway goes away and after you change your pants, drive slower...
 

sharps45

Petty Officer 2nd Class
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May 13, 2007
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Re: How to control sway after it starts?

First trailer was my 20 ft. camp trailer with brakes, boat was a small (15 ft) with single axle trailer. It isn't something I intended to do, and hope to not do again. But I was wondering about how to get out of the problem once in it.
Tandem towing under 55 ft is legal here.
 

Titanium48

Petty Officer 1st Class
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Apr 24, 2008
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Re: How to control sway after it starts?

For a single trailer, manually applying the trailer brakes without applying the tow vehicle brakes is very effective to stop swaying. It would probably also work in a double trailer situation if the lead trailer is considerably heavier than the end trailer.

Sway is an oscillation about the trailer's yaw (vertical) axis that takes the back end of the tow vehicle along for the ride. Sway can be a problem when the trailer is large relative to the tow vehicle and the trailer's inertial yaw axis (vertical axis running through the trailer's centre of mass) is close to the trailer's mechanical yaw axis (the axle(s)). In other words, when you don't have enough tongue weight.

Adding the second trailer puts more weight on the lead trailer's axles and simultaneously unloads the tongue, which can turn a marginally stable setup into an unstable one. The best double trailer setup (and the only legal one in many jurisdictions) is to use a 5th wheel hitch for the lead trailer, as 5th wheel trailers have their centre of mass well forward of the axle and will not be negatively affected by the tongue weight of the second trailer. If you're using 2 ball-type hitches, make sure the tongue weight of the lead trailer in the fully assembled "road train" is at least 10% of the sum of the lead trailer's weight and the end trailer's tongue weight.
 

codertimt

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Apr 3, 2008
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Re: How to control sway after it starts?

So you were towing a camp trailer and a boat behind that? In most if not all states, it's against the law to "double" tow unless the 1'st tow has a 5th wheel/gooseneck hitch. As to your question, normally on a single tow, slowing the speed usually stops or minimize the sway.

Actually only Arizona, Illinois, Michigan, and Minnesota have laws that state the first trailer must be a 5th wheel. The other 22 states that allow tandem towing only have max length requirements...and a couple have special permit requirements...
 

fishmen111

Chief Petty Officer
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Feb 1, 2008
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Re: How to control sway after it starts?

You should have dropped the boat after the first occurance. Many people have enough trouble getting one trailer set up correctly, much less two. Getting two pivot points in perfect unison takes work. Since it's over, I would have down shifted to activate the camper brakes if surge. If electric, about all you can do is slow down. If the camper does not have brakes at all, you should have never agreed to begin with. There is no instant cure for sway that I know of, other than having it set up correctly to begin with. I realize that these were special circumstances, but that was not wise decision.
 

sharps45

Petty Officer 2nd Class
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May 13, 2007
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Re: How to control sway after it starts?

Okay, I've been chastised for my good intentions. The haul was only about 18 miles, and except for the wind gust I kept it under good control.
I have electric brakes on my trailer, but didn't think of them at the time (I was busy sucking seat cushion into my nether region). Before I would try anything like that again, I would definitely do a better job of matching the trailer tongues, weights, and heights. The accelerate out of the sway sounds counter-intuitive, but makes sense when you think about it. How often do you get swaying when pulling up a grade?
Anyway, thanks for the advice and the wet noodle whipping.
 

RCSConstruction

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Mar 23, 2007
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Re: How to control sway after it starts?

The accelerate out of the sway sounds counter-intuitive, but makes sense when you think about it. How often do you get swaying when pulling up a grade?


I concor with the speeding up.
I had rented a trailer once that must have had a crooked axle or something but if I ever got above 50mph the trailer would start swaying (trailer was loaded properly:cool:). If I gave it brakes it would get worse but flooring it would straighting it right out. It was a tug of war all the way home and when I did get home and unloaded, my ball hitch's nut was two, maybe three threads from coming off!! Thing swayed so much it un-tightened my ball...
 

b_lish1966

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Apr 14, 2008
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Re: How to control sway after it starts?

I can definitely add a bit to this conversation, first all since you were only going 18 miles you should've left the boat and came back for it, now having said that since that isn't what you did and chose to risk wrecking all three vehicles, when sway starts the last thing to do is apply the brakes of the TV, a slight accel of the TV will sometimes straighten things out and then you can slow down to a safe tow speed, you can also apply the trailer brakes, but since you had a third vehicle in tow not sure honestly how effective that would be. Hope that next time you give serious thought to this tow arrangement and it's potential problems. Goodluck.
 

Shamic

Cadet
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Mar 31, 2008
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Re: How to control sway after it starts?

There is no debate on this at all. Dealing specifically with the question at hand, the ONLY safe way out is to accelerate until the sway subsides, then gradually reduce speed until you are at a safer speed. Trying to manually apply trailer brakes not only is unrealistic in a panic situation, but it also drastically increases the odds of the trailer wheels locking up, which inevitably leads to a jacknife.
 

ebry710

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Jan 29, 2008
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Re: How to control sway after it starts?

Determining how to tow two tandem trailers without knowing weight distribution and tongue length is difficult in a forum. Advising speeding up to stop sway could end up with trailers on their side. The best thing to do is drive slow and avoid sway altogether.

I have driven too many trailer to try this though. Legal or not my equipment and safety is too important to me.
 
Last edited:

Ezrider_92356

Chief Petty Officer
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Jul 14, 2007
Messages
426
Re: How to control sway after it starts?

one thing is dont try to steer to counter act it, it will only make it worse just keep driving straight down the road, apply the manual trailer break control without hitting the truck breaks and slow down
 

Shamic

Cadet
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Mar 31, 2008
Messages
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Re: How to control sway after it starts?

The last 2 replies are extremely incorrect. DO NOT TOUCH THE BRAKES! Trailer or otherwise, you must stabalize the vehicle first, which is done by accelerating only. I don't know where some of these guys get their information, but please do not mislead people when the wrong advice could lead to a crash. Obviously this vehicle combo should not have even been driven< HOWEVER once in trouble, the only choice you have is to get the trailer(s) back behind the tow vehicle and then slowly bring the vehicle to a safe speed or stop completely. This practice is well documented (Michigan centre for decision driving) not to mention well used by people who have a great deal of experience trailering a variety of loads and combinations.
 

mrmushroomman

Petty Officer 2nd Class
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Feb 27, 2008
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Re: How to control sway after it starts?

I agree that the last thing you want to do is hit the brakes. You should alway's speed up untill the trailer straightens up. When it is swaying the boat is pushing you and trying to get you to go faster than you want to go. By speeding up you are going to start pulling the boat again instead of having it try to push you and start swaying.
 

Titanium48

Petty Officer 1st Class
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Apr 24, 2008
Messages
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Re: How to control sway after it starts?

The last 2 replies are extremely incorrect. DO NOT TOUCH THE BRAKES! Trailer or otherwise, you must stabalize the vehicle first, which is done by accelerating only. I don't know where some of these guys get their information, but please do not mislead people when the wrong advice could lead to a crash. Obviously this vehicle combo should not have even been driven< HOWEVER once in trouble, the only choice you have is to get the trailer(s) back behind the tow vehicle and then slowly bring the vehicle to a safe speed or stop completely. This practice is well documented (Michigan centre for decision driving) not to mention well used by people who have a great deal of experience trailering a variety of loads and combinations.

The NHTSA, among others. "If you have an electric trailer brake controller and excessive sway occurs, activate the trailer brake controller by hand. Do not attempt to control trailer sway by applying the tow vehicle brakes; this will generally make the sway worse."
Reference: http://www.nhtsa.dot.gov/cars/problems/Equipment/towing/Towing.pdf

The idea is to re-establish tension between the tow vehicle and the trailer to damp the sideways oscillation. You can do that by accelerating the tow vehicle or braking the trailer. Both work, but trailer braking gets you to a slower, safer speed faster.
 
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