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Old 07-06-2011, 07:13 AM   #21
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Are you saying that you think the force of the sway control made the trailer loose traction? Or made the front wheels of the truck loose traction?
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Old 07-06-2011, 09:43 AM   #22
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Originally Posted by Bill M. View Post
Are you saying that you think the force of the sway control made the trailer loose traction? Or made the front wheels of the truck loose traction?
I am saying neither.
The vehicle lost traction in all wheels, trailer and truck, due to hydroplaning in water and diesel fuel. The hiitch was not the cause.

At this specific point of time during the accident I think, just my opinion, the tension force of the hitch was greater than the friction between tires and road. If this is true, did the tension of the torsion arms forced the trailer into a straight line behind the truck? Did this contribute to the fact that I could not regain control?
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Old 07-06-2011, 09:54 AM   #23
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Reading through your description of what happened, I'm not sure that the hitch contributed to the accident. It sounds like the problem was a lack of traction.
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Old 07-06-2011, 10:00 AM   #24
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Originally Posted by dznf0g View Post
This is the type of rare situation where I could see the newer vehicles with the combination of ABS, Traction Control, AND the newest electronic ITBC with trailer sway control could help maintain control. Some folks think these systems are gadgets, but AW makes a GREAT comment in the 4th paragraph.

These systems, contrary to popular belief, help maintain and regain directional control in a skid....not stop you quicker and in a shorter distance.
I agree totally!
But, brakes did not play a part in my incident. They were not applied.
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Old 07-06-2011, 10:34 AM   #25
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I think I mis-stated, so I'm re posting this portion

[QUOTE=A W Warn;1014043]The hitch was not the cause. QUOTE]

Corrected - The hitch was not the cause of the loss of traction, but may have contributed to me not being able to regain control.

Again, I think many of the comments are a critique of my experience, trying to say what I should'a or could'a done better. This is not where I was trying to go, but I do not mind the criticisms. I will try to learn from it!

For me the whole point of me sharing my experience with you is so that you (and I) may learn from what happened to me, so that someone else may be spared. This is the point of this forum too, I belive, to share and make us better at what we enjoy.

The essence of what I am trying to get at is:
Are the new sway controls that use tension to force the trailer into a straight line with the TV really any better than the friction controls that try to hold the trailer in it's fixed position.

If either device overcomes traction at any point, my opinion is one is not better than the other in this regard. What are your opinions on this specific issue?
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Old 07-06-2011, 10:41 AM   #26
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There are sway-resisting and sway-eliminating hitches. (and the "friction type" shouldn't be on anyone's list; they're nothing but doorstops).

The REESE Dual Cam is the best of the former type. PULRITE, PRO PRIDE and HENSLEY are the latter.

Of the latter, that trailer won't change direction until the drive axle (rear axle) of the tow vehicle changes direction (essentially no different than a fifth wheel setup).

Trailers are always trying to pass the TV. Take that for granted. (As I wrote in another post, I find it funny that people name their trailers . . on second thought at least they know whom to curse as that b#*%^ tries to come around).

Get the best hitch and set up the rigging according to scale readings. Tire pressure, axle alignment, wheel/tire balance, TV steering wander . . . make it all as good as can be. No stone unturned. And re-check regularly.

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Old 07-06-2011, 10:43 AM   #27
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Interesting, AW, that you are getting all sorts of opinions but few of the responses address your actual issue. I'm hoping someone with some engineering background relevant to the issue will weigh in. You've raised an important question.
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Old 07-06-2011, 11:36 AM   #28
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Interesting, AW, that you are getting all sorts of opinions but few of the responses address your actual issue. I'm hoping someone with some engineering background relevant to the issue will weigh in. You've raised an important question.
How can a loss of control [LOC] accident due to reduced traction be any more simply put than above? Had the trailer come around harder/faster then the rig would likely have jackknifed/rolled.

One need hardly be an engineer to understand that any mis-alignment between TV and TT once Steer Axle and Drive Axle traction was regained would have been a serious problem to overcome if not done just right.

The difference between TT and TV tire traction is the common cause of jackknife accidents. The hitch made a bad thing better.

A friction-type anti-sway must be disconnected in slippery conditions for if the trailer moves out/away from the direction of travel, as that type will "prevent" it from moving back quickly. This is what Inland Andy tries to communicate in speaking of "a brain": the point is to have the TT centered behind the TV for any condition encountered. The TT is not going to "save" the TV; just the opposite: the tail wags the dog.

The problem is vehicle mis-alignment from best to worst hitches as to lateral stability (and other considerations) for a given combination in the above.

It would be more to the point to produce the certified scale ticket for that rig from that day to determine "proper" Axle Loads in dissecting a LOC accident. Given a proven hitch then problems in hitch rigging is the place to start for an equipment discussion (past individual vehicle condition details. Tire type and condition for both vehicles would be the logical starting point for a traction problem). We're making static measurements to lessen/prevent dynamic problems.

In truth, LOC accidents are almost always written off to steering over-correction by the driver, and improper use of brakes. Time versus distance against inputs by the driver. Black box time. Give the driver the best tools (both vehicles, their components, and hitch + rigging) to cushion badly-done driver input. Once that TT moves away from the direction of travel of the TV all bets are off.

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Old 07-06-2011, 11:37 AM   #29
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[QUOTE=A W Warn;1014073]
Quote:
Originally Posted by A W Warn View Post
Are the new sway controls that use tension to force the trailer into a straight line with the TV really any better than the friction controls that try to hold the trailer in it's fixed position.
There may not be a good, all inclusive answer to your question. Like wwbrownrr, I'd like engineers to comment, but engineers don't agree either.

I, for one, am not criticizing your driving. The situation you describe sounds awful. I have been driving slowly with a good 4wd, good M+S tires, not towing, and lost all control and was lucky enough to eventually regain it or stop. I have been on an icy hill where everyone was sliding sideways while stopped because the road crown was sending us toward the ditch. I have been unable to stop on wet ice on a slight grade going a few miles an hour and tapped the next car's bumper, sliding him into the next guy in front of him.

It is possible no hitch would have changed things when the tires have no traction. And I think one hitch may solve some problems, but not others and you just have to pick the one with the fewest possible potential problems. Friction control may be better than tension sometimes, but not others. Could a hitch be designed to released tension or friction in such a situation? I could not have imagined skid/stability control, but it seems to work and doesn't cost all that much, so maybe an electronically controlled system could be designed although with a limited RV market, I suspect it would not be cheap.

I think your basic question is a good one and the thread wanders, as all threads do, possibly because no one really knows the answer. This is not the answer, but I do believe really good tires are just as or most important, but some are better on rain, some on snow, etc., and maybe none on diesel fuel.

I hope we get a definitive answer, but I am not optimistic, or if we do, I may not understand it.

Gene
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Old 07-06-2011, 11:49 AM   #30
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A W, what you are saying makes sense to me. The friction produced by the hitch prevents the trailer from changing its position behind the TV which is usually straight behind. When the trailer moves to the side, the friction on both the hitch and the trailer tires help bring it back into position.

Now consider the situation where you have NO friction between the tires and the road. It makes sense to me that at that instant where you noticed the trailer out to the side, the friction in the hitch probably did prevent the trailer from changing its position which wasn't exactly where you wanted it. Since you had no traction, your chances of getting things to come around were slim.

I do believe that this entire discussion is a hypothetical and should not be considered when trying to make a decision about which type of hitch you should use. In your case, with total lack of control on such a slick surface it wouldn't have mattered which hitch you were using. Once it got out there and as long as you had no traction, your fate was sealed to some extent. The fact that the trailer did come back around should make you feel better and it certainly was not your fault when the guy behind you smacked into you vehicle. If you are looking for fault, find the guy who spilled the fuel....and whoever caused the rain.

What you needed, and perhaps are looking for, is a hitch with some kind of built in spring that pushes your trailer back to a centered position. So when it is out to the side the hitch is actually trying to push it back to a normal position. Hey, you might be able to make a lot of money with something like this.
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Old 07-06-2011, 12:16 PM   #31
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I agree totally!
But, brakes did not play a part in my incident. They were not applied.
Doesn't matter (other than the fact that the systems are inter-related) Electronic sway control will sense yaw and apply brake at a singular or multiple wheels to pull you back in line whether your foot is on the brake or not. Some systems will automatically apply trailer brakes through the ITBC if the sensor input commands it too. This all happens more than 1o times a second....much faster than a driver can.
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Old 07-06-2011, 01:04 PM   #32
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Another factor with friction hitches is what happens when it is raining? When there's ice on it? When diesel splashes onto it? I would think there would be a reduction in friction allowing more sway or making it easier for the trailer to turn, maybe too much.

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Old 07-06-2011, 01:11 PM   #33
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I do not think any anti-sway system would have prevented or contributed to your accident. The fact you were towing a trailer, any trailer, did. When you began to skid, the mass of the sliding trailer minimized any effect of corrective steering input. A pickup pulling a trailer ain’t no Porsche.
In my opinion, the answer to your question is that any anti–sway device can overcome the traction of the entire rig, if the entire rig has lost traction and is in a slide.
Without the dual cam system, the trailer would have probably been jack-knifed alongside your tow vehicle, not in a straight line behind it. The “smarts” of the dual cam system is the fact that it does try to force the trailer into a straight line. The friction device just resists movement in any direction. As for being able to adjust the latter, yes, it is possible. But all you are really doing is giving up the effectiveness of the device.

I am glad you weren’t seriously hurt! Form the description you gave, your real problem was the fellow following you too closely.
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Old 07-06-2011, 03:55 PM   #34
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I appreciate all the responses and opinions!
And thanks for the kind words, yes we are lucky we were not seriouly hurt.

I think I'll bow out from commenting for a while, to wait and see if this discussion goes on. If some of you feel it is important enough, it will continue. If not let it go.
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Old 07-12-2011, 08:21 AM   #35
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The Reese dual cam sway control does not and will not force the trailer into a straight line with the tow vehicle.

The tow vehicle moving forward is the force that forces the trailer into a straight line behind the tow vehicle.

Did the hitch contribute to the loss of control? No. The tires losing contact with the road surface caused the loss of control.

Did the hitch contribute to not being able to regain control? No. Control will be regained when the tires reestablish contact and traction with the road surface.
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Old 07-12-2011, 10:02 AM   #36
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Torsion sway controls

Research done by Caravanner Insurance company, in 1970, more than proved that a "torsion type" sway control, made by Reese, properly installed with a proper rated hitch, properly installed, and properly adjusted, will "indeed" help the tow vehicle, straighten out, as long as the rig is on a decent pavement.

That can easily be demostrated by making a turn in a parking lot, and stopping, leaving the rig in a turn.

Get out of the tow vehicle and you can observe that there is a "twist" or "leaning" to one side.

Again, the word "proper" absoluely applies to many areas of "load equailzing hitches".

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Old 07-12-2011, 12:54 PM   #37
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From an engineering perspective, both friction type and spring type hitches are not ideal, because the forces they exert are not proportional to the rate of change of angle between trailer and tow vehicle.

In the case of a friction device, the force exerted is constant (for one setting of the device) and opposes motion. Properly lubricated, static coefficient of friction should be less than dynamic, so "stiction" won't be a problem. However the amount of force is not a function of rate of change of angle, so one can certainly propose situations (low speed on ice) where this device hinders control rather than aids it. This is not unlike the effect of limited slip rear ends on ice; since they force the wheels to attempt to travel at the same speed, in very limited traction conditions they will actually produce a skid.

In the case of a spring device, the force is largely proportional to the deflection between the tow vehicle and the trailer. This is quite similar to the effect of trailer tire slip in straight line motion, and no doubt helps explain the popularity of these devices since they help increase the speed at which instabilities occur. However, like the friction device, their effect is probably too much on ice or other very limited traction situations, since the amount of force applied is doesn't vary w/ speed of motion.

From an equation standpoint, the ideal damping device would be like a shock absorber - easy to move slowly, hard to move quickly. Thus, when one slowed for poor conditions, the resisting torques generated between tow and trailer would be similarly reduced.

Note that the so-called "sway eliminating" hitches do not eliminate the causes of trailer sway, but they make it much less likely to occur, typically by making the tow vehicle appear stiffer horizontally by moving effective hitch point to between the wheels and/or increasing the effective length of the trailer tongue. Load your trailer incorrectly, and sway can and does still occur.

Remember, however, that the majority of mysterious (not caused by obvious loading issues) trailer sway problems usually have a strong driver-induced component; the tow vehicle, trailer and driver form a dynamic system that may oscillate out of control. This is a well known problem in airplanes; this is why modern fighters, for example, are virtually all drive by wire as the driver's nervous system is incapable of providing correct direct control inputs. With our trailers oftentimes the best response to a sudden burst of wind or other disturbance is to do nothing at all; counter-steering can just inject additional energy into the disturbance.

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Old 07-12-2011, 02:07 PM   #38
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If we are trying to get our head around the workings of anti-sway devices, perhaps we have to use an imaginary situation. Imagine that we have a giant air hockey table and two large pucks. The pucks are big enough to get all four wheels of the TV on one and all four wheels of the TT on the other. The only connection between the pucks is the hitch between the TV and the TT which are sitting on their respective pucks. Now, our imaginary air table has two separately controllable sections that allow us to put air under the pucks separately or together as we desire.

So, we turn on the air under the TT puck. With no sway control, we can push the TT to any angle we want with the TV. There is no force to straighten it with the TV when we stop pushing so it remains at whatever angle we chose to leave it at. It also takes little force to bring it back into alignment.

With the friction sway control, it takes more force to move the TT out of alignment, and just as much to return it. The friction sway control wants to keep the TT where ever it is.

With the cam type sway control, it takes a force to move the TT out of alignment, and when that force is removed, the TT will be brought back into alignment by the cams.

Now, we turn on the air under both the TT and the TV pucks. When we push on the TT with no sway control, the TT will move relative to the TV (aka "jackknife"). The only force that could turn the TV is the friction on the hitch ball.

With either sway control, the TT and TV will move as a unit.

Therefore, towing an Airstream on ice or any other surface that eliminates friction between the tires and that surface is not recommended.
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Old 07-12-2011, 03:20 PM   #39
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The situation that the OP talks about is one that no engineer or users will agree on which hitch would have "saved the day", if any.

I can tell you, however, that I have used virtually every type of weight distribution hitch, anti-sway device built in my years of towing travel trailers, each type is an improvement over the previous. The friction sway control is better than no sway control. The Reese Cam sway control is better than the friction devise, assuming it is adjusted correctly, and that's a BIG assumtion. The newer Reese Dual cams is virtually impossible to keep properly adjusted, and very difficult to set up properly in the beginning. The older "classic" is much easier.

The newer types of hitches that eliminate sway are fantastic (I have the ProPride), and they are so far superior to the previous types, there is really no comparison. If you ever tow with one, you will never go back to ancient technology. Well, never unless you are in the business to sell the lesser hitches. Yes, they are more expensive, but to get more, most times you have to spend more, and how much money do you have invested in your tow vehicle and trailer, not to mention you and your family's life.
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Old 07-12-2011, 08:16 PM   #40
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Would a trailer be more stable if you had two balls several inches apart? Are two pivot points better than one? This is one of things I think of in idle moments.

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