Safety chain placement

Turtle n Peeps wrote:
All of you can set you brake cable anyway you want because it makes no difference to me at all. Pretty much all talk anyway because I would venture to guess about only about .001% of you that read this will ever have a hitch come off of the ball.

I can tell you what is going to happen if you set your cable to only come on when the trailer comes completely detached from the TV.

About 1981 I was a passenger in a truck with a very light car trailer (guessing around 1000 LBS)in tow that came off the ball.

Here is a play by play of what happen:

We were cruising down a straight freeway about 60 MPH when all hell broke lose.

#1. Big bang and the truck REALLY jerked!

#2. The driver hit his brakes instinctively. (Just like you are going to do if you ever have this happen. I don't care if you tell me you are not going to do this..........you ARE going to hit the brakes.)

#3. The trailer ran up under the truck and knocked the truck sideways. (It only takes a few inches off of center for 1000 to 9000 lb trailer acting as a battering ram to get your truck sideways.

#4. The trailer acted like a 1000 lb battering ram and either tried to lift the back end of the truck off of the pavement or DID lift the back end of the truck off of the pavement. (I couldn't be sure?)

#5. The driver was going lock the lock to keep the truck on the road.

#6. The driver would steer one way and the trailer would run up under the truck and ram the truck in the opposite direction. (this happened for what seemed like hours) :E

#7. The chain acted like a crack the whip. The trailer would run away from the truck, get to the end of the chain and would then snap the trailer under the truck again.........over and over and over.

#8. The trailer in question did not have brakes but I'm telling you there was no way in hell the driver would have be able the hit the manual control. And this guy could drive! He had his hands full just keeping the truck on the road.



Lessons learned for "me?"

#1. Make sure the trailer will not come off of the ball.

#2. Make sure the trailer in tow has brakes.

#3. Make very sure the trailers Ebrake comes on if the trailer ever comes off of the ball.

#4. A trailer set up with the ebrake coming on won't try to act as a battering ram and try and "PIT" your truck off of the road.

#5. Trailers have a lot of energy, even lite ones.

For those of you that are worried about trailer brakes coming on when the hitch comes off of the ball you have nothing to worry about. It happens every day on roads all over the world. Ever see long dually skid marks on the road? Most of the time it's caused by semi trailers losing air and locking up the brakes. Nothing happens except a smoke show and some flat sided tires and a red faced driver!

In any event, hook your trailer up how you want no matter how wrong it is. :B

You FIRST HAND experience that safety chains won't automatically "break" as some even in this thread contend is a fact along with this "ramming" of the trailer into the TV are important considerations IMO. You scenario with a trailer w/o brakes is for sure the worst case I can think of and as you confirmed makes for "ONE WILD RIDE":E I agree with your feeling that it will take "LUCK" for one to stay off the TV brakes in an emergency disconnect scenario, and my only suggestion is to periodically like several times an hour to say to your self, NO BRAKING, NO BRAKING, NO BRAKING and them just hope for the best which is all we can do in the end and at least with full trailer braking happening automatically this mistake of applying the TV brakes will at least be somewhat minimized.

Larry

All of you can set you brake cable anyway you want because it makes no difference to me at all. Pretty much all talk anyway because I would venture to guess about only about .001% of you that read this will ever have a hitch come off of the ball.

I can tell you what is going to happen if you set your cable to only come on when the trailer comes completely detached from the TV.

About 1981 I was a passenger in a truck with a very light car trailer (guessing around 1000 LBS)in tow that came off the ball.

Here is a play by play of what happen:

We were cruising down a straight freeway about 60 MPH when all hell broke lose.

#1. Big bang and the truck REALLY jerked!

#2. The driver hit his brakes instinctively. (Just like you are going to do if you ever have this happen. I don't care if you tell me you are not going to do this..........you ARE going to hit the brakes.)

#3. The trailer ran up under the truck and knocked the truck sideways. (It only takes a few inches off of center for 1000 to 9000 lb trailer acting as a battering ram to get your truck sideways.

#4. The trailer acted like a 1000 lb battering ram and either tried to lift the back end of the truck off of the pavement or DID lift the back end of the truck off of the pavement. (I couldn't be sure?)

#5. The driver was going lock the lock to keep the truck on the road.

#6. The driver would steer one way and the trailer would run up under the truck and ram the truck in the opposite direction. (this happened for what seemed like hours) :E

#7. The chain acted like a crack the whip. The trailer would run away from the truck, get to the end of the chain and would then snap the trailer under the truck again.........over and over and over.

#8. The trailer in question did not have brakes but I'm telling you there was no way in hell the driver would have be able the hit the manual control. And this guy could drive! He had his hands full just keeping the truck on the road.



Lessons learned for "me?"

#1. Make sure the trailer will not come off of the ball.

#2. Make sure the trailer in tow has brakes.

#3. Make very sure the trailers Ebrake comes on if the trailer ever comes off of the ball.

#4. A trailer set up with the ebrake coming on won't try to act as a battering ram and try and "PIT" your truck off of the road.

#5. Trailers have a lot of energy, even lite ones.

For those of you that are worried about trailer brakes coming on when the hitch comes off of the ball you have nothing to worry about. It happens every day on roads all over the world. Ever see long dually skid marks on the road? Most of the time it's caused by semi trailers losing air and locking up the brakes. Nothing happens except a smoke show and some flat sided tires and a red faced driver!

In any event, hook your trailer up how you want no matter how wrong it is. :B

coolbreeze01 wrote:
Good pics Larry. Should help those wanting to hook up correctly.

Thanks and the one thing I have done, but didn't take pics is I at one time I blocked the TT wheels, connected the safety chains only with the ball off the tongue and then pulled the TV slowly forward confirming that the crossed chains would in fact "LIFT" the tongue off the pavement. Now obviously I have never and hope to never be able to report how things work in a real disconnect, but from all my tests I believe how I have my setup done and will work to the best I can determine is the best. I guess to close things out with this worry about "locking" up the wheels in one of Rons replies to my belief that this is really not an issue he provided some calculations suggesting what I was asserting was probably correct. I have also tested the full amerage breaking (12A to the magnet ckt) and I can't lock up my wheels at any speed over about 20 to 25 miles per hour on dry pavement. In any event I really don't care if they lock up at a slow speed since within a few seconds the speeds will be so slow that the real dangerous situation is for the most part passed. Also, with the centerline tracking that crossed chains from a common attachment point provides any swerving of the trailer due to skidding tires will tend to straight the trailer out just like you would do to straighten a trailer out in a sway event, by carefully applying the TV brakes only.

Finally, I guess I get a little worked up when I see folks throwing around what I can only call "WILD CONJECTURES" with absolutely no supporting data when I have done a lot of the "belt and suspenders" type work as best I can to address most of these WAGs and while no perfect, outside of the work done by JBarca on the chain lengths have seen no tests or pics supporting these what I call "WILD CONJECTURES".

Larry

Good pics Larry. Should help those wanting to hook up correctly.

LarryJM wrote:

gijoecam wrote:


Second, I have yet to see a configuration that would allow the breakaway cable to be pulled when the coupler separates from the ball but the chains are still attached. It would require some very specific-length cables and attachment points such that the cable is pulled if the ball drops more than a couple of inches, and that assembly would still need to be able to articulate as the rig makes turns and traverses hills and valleys. That setup only exist in theory as best I can tell...

You are correct that your cable lengths need to be closely set and I have mine where when the safety chains are fully extended the breakaway switch is pulled, but the 7 pin cable hopefully will still be connected. I have tested my configuration by attaching all the cables/chains with the tongue off the ball and at the same height as it would be normally and then slowly pulling the TV forward till the chains are taught. Here is a picture of what my "ACTUAL CABLES/CHAINS
" looks like and this is not a theory, but real and I'm sorry if you still don't believe it's possible, but I know along with a lot of other folks in past posts say it is ;):



Larry

I posted before reading through JBarca's post linked earlier in this thread... I stand corrected as I now see that it *is* possible to set up the arrangement such that it'll pull the safety cable before detatching.

(I've been wrong before... It happens...) ;)

There is, of course, the eternal debate as to whether or not this is the preferred sequence. On my particular vehicle, I would have a difficult time making it happen as there is no other attachment point for the safety cable anyways. Unlike JBarca's bumper, I don't have a tow-capable bumper with the auxiliary safety chain connections on it. In fact, on my particular truck, the nearest thing to an attachment point that's NOT a safety chain connection on the receiver is another three feet farther up the frame, adding to the challenge.

BTW below are two pics I took some years ago when discussing this cross or not to cross and how using a single attachment point works in the real world. The first pic shows how the chains will ride up on each side of the end of the tongue allowing the end of the tongue to catch on the pavement and the second shows what the crossed chains look like. What the cross chains do is move the center of the crossing of the two chains up almost under the end of the coupler forming the cradle effect that forms the "skid" I have refered to and when tensioned will "lift" the tongue off the pavement while keeping the forward pull centered on the tongue and directly behind the TV. This crossing prevents the chains from being able to ride up on the sides of the tongue and allowing the end of the tongue to contact the pavement directly. This lifting will be fairly constant as long as you have sufficient braking applied and you don't apply the TV brakes so the TT is deaccelerating much faster than the TV.

UNCROSSED:


CROSSED:


Larry

gijoecam wrote:


Second, I have yet to see a configuration that would allow the breakaway cable to be pulled when the coupler separates from the ball but the chains are still attached. It would require some very specific-length cables and attachment points such that the cable is pulled if the ball drops more than a couple of inches, and that assembly would still need to be able to articulate as the rig makes turns and traverses hills and valleys. That setup only exist in theory as best I can tell...

You are correct that your cable lengths need to be closely set and I have mine where when the safety chains are fully extended the breakaway switch is pulled, but the 7 pin cable hopefully will still be connected. I have tested my configuration by attaching all the cables/chains with the tongue off the ball and at the same height as it would be normally and then slowly pulling the TV forward till the chains are taught. Here is a picture of what my "ACTUAL CABLES/CHAINS
" looks like and this is not a theory, but real and I'm sorry if you still don't believe it's possible, but I know along with a lot of other folks in past posts say it is ;):





Larry

gijoecam wrote:
Second, I have yet to see a configuration that would allow the breakaway cable to be pulled when the coupler separates from the ball but the chains are still attached. It would require some very specific-length cables and attachment points such that the cable is pulled if the ball drops more than a couple of inches, and that assembly would still need to be able to articulate as the rig makes turns and traverses hills and valleys. That setup only exist in theory as best I can tell...

If the breakaway cable is routed directly above the coupler (e.g. through the coupler padlock), it can be tight without causing issues while turning. Not that I have an opinion about whether it should pull first or not. :)

BarneyS wrote:
I am trying my best to keep this thread open but if there are any more flaming posts it will be closed.
Barney

You can close it Barney. In my opinion there are people that have not seen my trailer or apparently muddydogs trailer also, so they have no idea how crossing the chains, does nothing. Regardless of what the law or other people insist, first hand knowledge trumps. It's as useless as a screen door on a submarine.

gmw photos wrote:
The way I read the DOT requirements for the breakaway cable, it specs the switch must be activated to apply the trailers brakes after the trailer has separated from the tow vehicle. It does not specify "when" in this chain of events. Where the safety chains are presumably keeping the rig together ? Or after a total breakaway ?

Strictly speaking, it "sounds" to me like the reg is saying "after the hitch connection has failed, and also after the safety chain connection has failed".

Right, wrong or otherwise, I have my breakaway cable connected in a way that the pin would only be pulled in the event the safety chains failed, and the trailer is totally disconnected from the truck.
Personally, I would not want the trailer brakes locked and sliding, especially if it happened to be wet pavement, while the trailer is still hanging on by the chains.

YMMV....and your connections may vary as well....

I agree with you on this for two reasons: First, it's the only thing that makes sense. Locking the trailer brakes while the trailer is still attached to the tow vehicle by the safety chanins isn't a good idea.

Second, I have yet to see a configuration that would allow the breakaway cable to be pulled when the coupler separates from the ball but the chains are still attached. It would require some very specific-length cables and attachment points such that the cable is pulled if the ball drops more than a couple of inches, and that assembly would still need to be able to articulate as the rig makes turns and traverses hills and valleys. That setup only exist in theory as best I can tell...