Something is going on: Airstream rollover three

[Rfriebele]

These responses made me ponder something.. having the ultimate hitch setup hoping to never encounter sway or knowing how to correct it if it happens? I've always been a 'worst case scenario' type so even with the ultimate setup, I wouldn't trust that it could never happen and I'd be sure to know what to do and what not to do if it did. But that's just me. Who knows if these poor folks had a better setup, this situation might never have happened....where & when it did. But to me, that's like rolling dice cause eventually, that bad number will come up.

[J. Morgan]

Originally Posted by jcl

We may be using different definitions of sway here.



In my experience, all trailers sway. You can follow them, all designs and hitch configurations, and watch it. Usually there is sufficient damping inherent in the system so that it isn't a problem, and often the person driving will be unaware of it, but may be able to see it in their mirrors.



The problem is when there is insufficient damping, and then we get escalating sway events that get discussed on forums. That is the type of sway that some may be referring to when they say that their trailer has never swayed. It is a different definition of sway, however.



IMO, this difference in definitions makes the PPP vs all the others debate more difficult because of a lack of agreement on basic terms.

The semi-trailers (i.e. fifth wheel) I have pulled for more than 30 years don't sway. If they did, I would say so. Now, there seem to be more and more truck drivers that can't or wont drive straight in a lane, but a semitrailer will generally track in the truck tractors footprint.

Just my experience.

[franklyfrank]

Originally Posted by tjdonahoe

Pulled ou as across North Dakota yesterday, had a side wind,and head wind all the way ,no sway with the Reese duel cam, also the ram is at 9600 and our classic had 7800 on the axle full of water and supplies.....

You must have been hallucinating. That could't possibly be without a ProPride or Hensley don't you know. :-)

[pteck]

I'm only familiar with my Prodigy P3, and it indeed has a setting to do just as you describe.

It has 3 boost settings: B1, B2, B3. With each step more aggressive than the next.

What it does is essentially have the trailer brakes lead the tow vehicle brakes by immediately applying higher brake pressure to the trailer, as it senses any brake application at the tow vehicle (via brake lights). Such that braking is always done with the hitch in tension.

I always run some form of boost (B1 or B2) on the highway. B2 during higher speeds, winding roads, or steep declines. I tend to turn it off in the city as it can be a bit grabby at lower speeds.

There hasn't been much discussion on this, but I believe this type of feature allows less reliance on the manual override when trying to stabilize a trailer in initial sway, or likely sway situations. At a minimum, it begins engaging the trailer brakes much more quickly than one can by reaching for the override. Though as a habit, my hand is near the brake controller during more tenuous scenarios.

[Rich Jenkins]

Originally Posted by pteck

I'm only familiar with my Prodigy P3, and it indeed has a setting to do just as you describe.

It has 3 boost settings: B1, B2, B3. With each step more aggressive than the next.

What it does is essentially have the trailer brakes lead the tow vehicle brakes by immediately applying higher brake pressure to the trailer, as it senses any brake application at the tow vehicle (via brake lights). Such that braking is always done with the hitch in tension.

I always run some form of boost (B1 or B2) on the highway. B2 during higher speeds, winding roads, or steep declines. I tend to turn it off in the city as it can be a bit grabby at lower speeds.

There hasn't been much discussion on this, but I believe this type of feature allows less reliance on the manual override when trying to stabilize a trailer in initial sway, or likely sway situations. At a minimum, it begins engaging the trailer brakes much more quickly than one can by reaching for the override. Though as a habit, my hand is near the brake controller during more tenuous scenarios.

Excellent, thanks. Very interesting.

[slowmover]

Originally Posted by franklyfrank

You must have been hallucinating. That could't possibly be without a ProPride or Hensley don't you know. :-)

Any observer would have seen the trailer constantly move out of alignment with the TV. Wind or no wind. One side to another. A Dual Cam will show the wear.

"Sway" is of higher amplitude.

[slowmover]

Originally Posted by pteck

I'm only familiar with my Prodigy P3, and it indeed has a setting to do just as you describe.

It has 3 boost settings: B1, B2, B3. With each step more aggressive than the next.

What it does is essentially have the trailer brakes lead the tow vehicle brakes by immediately applying higher brake pressure to the trailer, as it senses any brake application at the tow vehicle (via brake lights). Such that braking is always done with the hitch in tension.

I always run some form of boost (B1 or B2) on the highway. B2 during higher speeds, winding roads, or steep declines. I tend to turn it off in the city as it can be a bit grabby at lower speeds.

There hasn't been much discussion on this, but I believe this type of feature allows less reliance on the manual override when trying to stabilize a trailer in initial sway, or likely sway situations. At a minimum, it begins engaging the trailer brakes much more quickly than one can by reaching for the override. Though as a habit, my hand is near the brake controller during more tenuous scenarios.

Honest-to-God sway correction means throttle slammed open and TT brakes manually applied hard as they'll go. One might have 1.5-2.0 seconds at 55-mph to recover. And that's generous.

.

[slowmover]

Originally Posted by J. Morgan

The semi-trailers (i.e. fifth wheel) I have pulled for more than 30 years don't sway. If they did, I would say so. Now, there seem to be more and more truck drivers that can't or wont drive straight in a lane, but a semitrailer will generally track in the truck tractors footprint.

Just my experience.

You've never heard of or seen a jackknife? That's how some occur. Driver locked the trailer brakes and it came around.

It's not just wet, muddy or icy roads. On which a trailer winds up traveling faster than the tractor.

That some trailers are easier to control at highway speeds isn't the point. Run fast enough and any of them will sway. It's built in.

[wolf146]

"towing our 23 foot Safari behind a 2006 Tundra. The plug, between tailer and truck, had fallen out. I did not notice until refueling and part of the trailer's plug had ground down on one side. I now always use Duct Tape to secure this connection between vehicle and trailer in tow."


Same thing happened to me. I switched from duct tape to a velcro strap which works very well with less hassle.

Wolf146

[J. Morgan]

Originally Posted by slowmover

You've never heard of or seen a jackknife? That's how some occur. Driver locked the trailer brakes and it came around.



It's not just wet, muddy or icy roads. On which a trailer winds up traveling faster than the tractor.



That some trailers are easier to control at highway speeds isn't the point. Run fast enough and any of them will sway. It's built in.

A jackknife isn't sway. A jackknife is usually the result of the tractors axles breaking traction and moving to the left or the right under poor traction conditions and/or hard braking conditions. At that point the trailer might slide around the tractor as inertia takes control.

[J. Morgan]

Originally Posted by J. Morgan

A jackknife isn't sway. A jackknife is usually the result of the tractors axles breaking traction and moving to the left or the right under poor traction conditions and/or hard braking conditions. At that point the trailer might slide around the tractor as inertia takes control.

Oh I forgot to mention, I have never ever ever had a semi trailer or any of my fifth wheel trailers sway, not once, never. I have logged a lot of miles over many years. I have observed doubles and triples swaying, and I have seen stinger coupled car hauler trailers sway going down the road, but I have never seen a single semi-trailer sway. Ever.

I would be inclined to say that if you have had a single trailer sway behind your tractor, or if you have seen a single semi trailer swaying going down the road, then there is something really bad wrong with its suspension.

[jcl]

There are products sold for 3/4 and 1 ton pickups to reduce trailer sway with recreational 5th wheel trailers. They seem to believe there is a market for such products. They stiffen up the truck rear suspension and add a heavier duty anti-roll bar to counteract trailer sway with what I would consider top heavy 5th wheels, with significant side surface areas to catch wind gusts.

A better balanced 5th wheel trailer driven at reasonable speeds wouldn't require such devices, IMO.

And this is apart from the people towing 5th wheels with short bed pickups who position the coupler aft of the truck rear axle due to interference risks with the trailer and truck cab.

[OTRA15]

. . . and, keeping mind the original post here, this thread demonstrates that controlling sway is something that either works in the first second or two . . .

. . . or . . .

IT'S OUTTA CONTROL . . . !

[Countryboy59]

Originally Posted by slowmover

Honest-to-God sway correction means throttle slammed open and TT brakes manually applied hard as they'll go. One might have 1.5-2.0 seconds at 55-mph to recover. And that's generous.

.

Locked trailer brakes and spinning truck tires sounds like it would make things worse. You would need to time the brake application just right to avoid making things worse.

[OttawaValleyGuy]

Well Mr. Countryboy........who said LOCKED TRAILER BRAKES and SPINNING TIRES ?
Applying the trailer brakes hard and powering is the very best way of handling a swaying trailer!!!

[Rfriebele]

Originally Posted by Countryboy59

Locked trailer brakes and spinning truck tires sounds like it would make things worse. You would need to time the brake application just right to avoid making things worse.

Sounds radical to slam the gas & lock the trailer brakes but I've never done that. My brush with death was when I first started towing and didn't fully understand the rules of distribution. I had a 22ft. trailer on a TV w/ a cheap brake controller and I added a large heavy bike rack to the very back throwing the balance out completely. I felt a little sway at around 65 mph at first but soon as a semi roared past me, it imparted a monster sway that could have wrecked us. Fortunately, i knew enough to resist the urge to try and 'steer the trailer' back to center figuring if the TV goes straight, eventually so will the trailer and I slowly let off the gas reminding myself that it didn't do this at 40mph. I focused on the center of the lane & only moved my hands to my visual target which to be honest, in the moment, feels wrong, like not enough of a steering correction which now makes me understand how someone who starts fishtailing, goes from bad to worse to ditch. Anyway, keeping the TV pointing straight & slowing gradually quickly got it under control. Then it was staying at a speed that minimized the harmonic. 50-55. Needless to say, weight distribution had to be modified first chance & now that I have a much bigger trailer, sway is something I can anticipate & correct like turning a corner.

[OttawaValleyGuy]

You make a valid point.........do not try to steer the trailer......keep the tow vehicle straight !!

[pteck]

Originally Posted by slowmover

Honest-to-God sway correction means throttle slammed open and TT brakes manually applied hard as they'll go. One might have 1.5-2.0 seconds at 55-mph to recover. And that's generous.

.

The whole point with trailer brakes leading the tow vehicle brakes is to mitigate "honest-to-god sway". It keeps the lash-up in tension, by reducing trailer momentum first, such that the trailer does not want to overtake the tow vehicle. I'm sure you know that trailer momentum and it wanting to overtake the tow vehicle is the primary energy source for sway.

[GCinSC2]

Originally Posted by Llando88

Actually I have a question.

Does anyone know if modern TV factory braking systems do or do not apply the TT brakes slightly ahead of the TV?

Seems it would be possible for software to do this. The TV knows it's in tow/haul mode (mine has a switch) and it also knows there is a TT attached (via the umbilical.)

Thoughts?

Consider reviewing your controllers manual regarding what it uses to start the braking of the trailer. Pendulum was an older design, I bet many now have sensors that sense deceleration.

Your TV brakes are mechanical / hydraulic and are controlled by your leg and foot initiating the braking and creating the pressure to the brakes.

[Countryboy59]

Originally Posted by OttawaValleyGuy

Well Mr. Countryboy........who said LOCKED TRAILER BRAKES and SPINNING TIRES ?
Applying the trailer brakes hard and powering is the very best way of handling a swaying trailer!!!

That's what I get if I floor it and squeeze the trailer brake control.

Best way to handle sway is to not insist on going so damn fast.