Breakaway Cable Length - What do you do?

[DreamStreamr]

What length, relative to the safety chains, do you use for the breakaway cable on your rig?

Statutes, standards, and recommendations spell out the requirement for a breakaway switch on travel trailers like our Airstreams. The setup length of the cable is not specified in U.S., Canada, or U.K. statutes or standards as far as I can detect. Fred Ettline writing in Blue Beret in May 2006 (Phred Sez) makes a reasonable argument for making the breakaway switch cable longer than your safety chains. Equal-i-zer, HaHa, and Reese seem silent on this issue (perhaps either because it is not specifically a hitch issue or it would add unneeded liabilities to recommend upon?).

And a good writer named Tim writes on his pop-up camping web site some pros and cons of the cable shorter or longer and wisely, perhaps, tells you to pick one of the two. On a caravan this summer one of our deparkers was adamant in his contention the breakaway switch must activate first, not last, in the event of accidental separation of trailer and truck (decoupling). He even (I am terribly ashamed to share) reported me to the Region III Safety Officer. I'll try to let you know how (if and when) this resolves.

Granted, if the decoupling was caused by the tow vehicle's hitch failure, the chains almost certainly aren't connected anymore. We would probably all agree upon full breakaway switch activation to stop an out-of-control trailer. But what if the trailer decouples partially but not completely from the tow vehicle? What if the drawbar comes out of the receiver or the coupling comes off the ball, or the ball came off? What if the trailer becomes unhitched as you tool down the highway and the trailer coupler or hitch head now are resting upon the safety chains? "Hey dad, the trailer just ran into the back of our truck again!"

If your breakaway switch immediately engaged upon decoupling, you will engage all the trailer's brakes at full capacity. If, and this is where I tow most, you are on dry pavement, the trailer brakes will probably produce an intense and sudden stress upon the safety chains, loops, and hooks. And you will produce a sudden and surprising yank back on the tow vehicle. One or the other of these things, it seems, would likely create severe and perhaps unnecessary vehicle control issues, particularly if you happen to be on a curve just then. Are these good things?

Which length breakaway cable do you choose, and what's your rationale?

[Inland RV Center, In]

Originally Posted by DreamStreamr

What length, relative to the safety chains, do you use for the breakaway cable on your rig?

Statutes, standards, and recommendations spell out the requirement for a breakaway switch on travel trailers like our Airstreams. The setup length of the cable is not specified in U.S., Canada, or U.K. statutes or standards as far as I can detect. Fred Ettline writing in Blue Beret in May 2006 (Phred Sez) makes a reasonable argument for making the breakaway switch cable longer than your safety chains. Equal-i-zer, HaHa, and Reese seem silent on this issue (perhaps either because it is not specifically a hitch issue or it would add unneeded liabilities to recommend upon?).

And a good writer named Tim writes on his pop-up camping web site some pros and cons of the cable shorter or longer and wisely, perhaps, tells you to pick one of the two. On a caravan this summer one of our deparkers was adamant in his contention the breakaway switch must activate first, not last, in the event of accidental separation of trailer and truck (decoupling). He even (I am terribly ashamed to share) reported me to the Region III Safety Officer. I'll try to let you know how (if and when) this resolves.

Granted, if the decoupling was caused by the tow vehicle's hitch failure, the chains almost certainly aren't connected anymore. We would probably all agree upon full breakaway switch activation to stop an out-of-control trailer. But what if the trailer decouples partially but not completely from the tow vehicle? What if the drawbar comes out of the receiver or the coupling comes off the ball, or the ball came off? What if the trailer becomes unhitched as you tool down the highway and the trailer coupler or hitch head now are resting upon the safety chains? "Hey dad, the trailer just ran into the back of our truck again!"

If your breakaway switch immediately engaged upon decoupling, you will engage all the trailer's brakes at full capacity. If, and this is where I tow most, you are on dry pavement, the trailer brakes will probably produce an intense and sudden stress upon the safety chains, loops, and hooks. And you will produce a sudden and surprising yank back on the tow vehicle. One or the other of these things, it seems, would likely create severe and perhaps unnecessary vehicle control issues, particularly if you happen to be on a curve just then. Are these good things?

Which length breakaway cable do you choose, and what's your rationale?

Short enough so that is doesn't drag the pavement and long enough so that it cannot activate on a tight turn.

The actual length depends on the trailer-tow vehicle combination.

The length also will vary depending on where the break away cable is attached to the tow vehicle.

That cable should never be attached to the ball or ball mount, as some owners do.

Andy

[markdoane]

I'm not trying to kill your thread, but here are a couple of earlier threads that make interesting reading.

An early thread. .

. . . and an earlier one.

[hampstead38]

I think a partial failure is much more likely than a complete failure. Here's my concern. Let's say hitch pin fails and the entire assembly slides out of the hitch and the tongue falls onto the properly crossed safety chains. Not pretty, but hopefully the safety chains hold keeping the tongue off the pavement and the driver can roll onto the side of the road. If the breakaway cable is shorter, it releases and the trailer brakes engage. Now, if I'm rolling along at 55 mph, the force may be enough to snap the chains and bring a whole new meaning to the phrase, "silver bullet." Even if the chains hold, the force may be enough to result in a loss of control. Now, as long as the safety chains don't fail, there will still be power to the trailer brakes allowing the gentle manual use of the trailer brakes to avoid having the tongue "spear" the rear. So, my thought is that the breakaway switch exists to ensure the trailer stops if it "breaks away."

[richinny]

ok, i read the two mentioned threads. now i have questions.

do the trailer brake lights activate when the break away switch is activated?

i see that some folks don't like the s hooks on their chains and used closed fasteners. i'd think that i would want the trailer to become separated from the tow veh. (with brakes applied) if there was so much force as to open the s hooks, so i could try to get the tv safely stopped. comments?

a simple solution to short/long activation cord would be two switches with short cord on one giving partial voltage/braking for partial emergency and a longer cord for the second switch for "oh poop" situations.

as for 'saving the controller from frying' with the long cord....... i would hope it would be the least of my problems in that situation!

[Inland RV Center, In]

Originally Posted by richinny

ok, i read the two mentioned threads. now i have questions.

do the trailer brake lights activate when the break away switch is activated?

i see that some folks don't like the s hooks on their chains and used closed fasteners. i'd think that i would want the trailer to become separated from the tow veh. (with brakes applied) if there was so much force as to open the s hooks, so i could try to get the tv safely stopped. comments?

a simple solution to short/long activation cord would be two switches with short cord on one giving partial voltage/braking for partial emergency and a longer cord for the second switch for "oh poop" situations.

as for 'saving the controller from frying' with the long cord....... i would hope it would be the least of my problems in that situation!

Ricky.

The brake wires are independent of all other circuits. So when the breakaway cable is pulled, only the brakes are activated, assuming you have a battery in the circuit, and that is has a charge.

Should a trailer breakaway, you want "all" the power you have availble to go to the trailer brakes.

Should the trailer breakaway, no one has any idea what direction it may take. It would depend on the street or highway, and the speed at the time.

Typically, when a trailer breaks away at highway speeds, it's more that likely to roll over.

Therefore applying maximum power to the brakes, is all that a person can do.

In the case of a breakaway, it shouldn't, but could fry the controller. I think you will find that you would have many more problems than just a fried controller.

Safety chains can be inspected by highway patrol people. If they are not reasonably safe, talk has it that they can issue a ticket, especially to someone who says "I don't want the trailer to hang on to my tow vehicle should it break away", so they cut one link to make it very weak.

Bad idea, at best.

Andy

[richinny]

thanks andy.

i wasn't thinking of weakening the chains. i've seen comments/pictures elsewhere of s links stretching open and disconnecting. no videos to examine but with new technology, who knows what we'll see in the future.

[DreamStreamr]

We drove up I-5 from Bakersfield, Ca to Medford, Or today. Many of the California bridges were well above the interstate grade so we had a few big hops for the trailer, despite driving only 55mph. If a coupling was going to give up sometime, or a hitch to separate from the trailer on an Interstate, these would seem candidate locations. So, if I was the driver following a just released trailer, I would dearly love to receive one more cue than just a sudden wobble from the trailer in front of me. I would want brake lights or flashers.

Granted, everything is going to take place pretty instantaneously. A split second is all the following driver would have. And depending upon following distance, a warning light could attract his attention and provide that chance of survival to avoid smacking the very suddenly slowing trailer/barricade in front of him.

In other forums I've read persons who added a second set of contacts from the breakaway switch to engage brake lights. My Airstream's 230 amp hour battery set would not know the difference of added flashing rear lights or solid brake lights. The batteries would still have full voltage for brakes and lights both.

Very slight chance of this all going wrong and needing the safety margin, but safety is about infinitesmally small chance of unlikely things happening. Following the unintended consequence rule: Would this cause another problem? Or is this just another solution looking for a problem?

[ROBERTSUNRUS]

Hi, My breakaway cable and safety chains are exactly the lenght that Airstream made them. They aren't too tight or drag on the ground. If you had to change the length of your chains for your hitch [Hensley Arrow] then I would add the same amount to the breakaway cable. What is the real story? Did you modify your cable?

[DreamStreamr]

Hi Bob,
Yeah, in fact, my safety chains are two links shorter because they did drag as configured by Airstream. And I shortened the breakaway cable a little, so it remains longer and it was longer as configured by Airstream.

[DreamStreamr]

I read through the two earlier threads about breakaway cable lengths. No one provided science-based rationale for the breakaway cable to be shorter than the chains. One poster recalled Reese guy (Doug Showker, maybe?) at Region 6 Rally saying to shorten the breakaway cable. Another poster weighed in later and said, yeah, he heard the same but also heard the context -- the breakaway cable length, if excessive, can snag on road hazards and activate. But the cable length still, apparently, is longer than the safety chains.

In the absence of science, Airstreamers seem left with a large body of anecdotal evidence and need to carefully make their own decision. I'm hoping someone will turn up scientific evidence or bona fide manufacturers' recommendation for one method or the other.

Until then I'm keeping my chains short and crossed and snapped securely onto the hitch receiver eyes. I'll keep the breakaway cable longer than the chains. And I want to keep the cable free from snagging on anything, if I can. I'll test the breakaway switch at least monthly by pulling it then quickly checking for compass needle deflection at each wheel. Takes just over 60 seconds, and provides the benefit of knowing the pin will release and seeing activation of each wheel's magnet.

My two cents worth - - - What d'ya think?

[ROBERTSUNRUS]

Hi, DreamStreamr. I think you will be just fine with the chains and cable, as you decribed, in the previous post.

[DreamStreamr]

Bob,
Agreed, and appreciate your input. It's interesting how fervent we get over certain issues, and I fervently hoped I would find an absolute for this question. One way or the other. I did find a consensus and it seems consistent, for the most part, with the other threads addressing this topic.

No one, nada, nobody provided an absolute technical argument for making the cable shorter than the chains. And, I think, the same lack of substantive evidence goes for making the cable longer than the chains.

We are left, then, making our own decision. Not a terrible thing, to have a choice. It is very important, this decision, but two things weigh in our favor in either decision. The odds of a true breakaway are pretty tiny, given the driver thoroughly checks all aspects of the hitch receiver, drawbar, and ball attachments. And in a breakaway situation the trailer will stay attached (and hopefully in control) or it will detach and will (hopefully) fully apply the brakes.

I was looking for the easy way out, you know, the irrefutable scientifically evidenced one answer. Instead we make a choice on whether to have the cable shorter or longer.

[Diesel1]

Ford Motor Company at their Arizona Proving Ground(APG) did duribilty testing on Ford light trucks. Part of the test included trailer towing at max GVW.All of the breakaway cables were longer than the crossed safety chains and not attached to any portion of the hitch.

[jsprad]

For what it's worth, I have been told by three RV dealers (the last one being an Airstream dealer) that it's good to have the breakaway cable longer than the chains. Two of them have even independantly suggested pulling the cable through two or three links of one of the chains to help keep the cable from dragging the ground or cathching easily on something. Then pull the remaining slack of the cable through the links in the chain and attach it to the tow vehicle.

[Excella CM]

Another parameter for break away cable length concerns newer high-tech electronic brake controllers. Since activating the break away switch with umbilical connected to the TV can damage the controller, I would seem prudent to make sure the length of the cable is adjusted so that during an unhitching incident, the umbilical comes out first.

[Cracker]

Originally Posted by Excella CM

Another parameter for break away cable length concerns newer high-tech electronic brake controllers. Since activating the break away switch with umbilical connected to the TV can damage the controller, I would seem prudent to make sure the length of the cable is adjusted so that during an unhitching incident, the umbilical comes out first.

I think that the umbilical would be the last thing I would worry about with reference to damaging the controller. For the record, I use a plastic tie around the umbilical plug and the retaining cap on the car plug to prevent an accidental "unplugging" of the umbilical. I'm not sure what would happen to the plug and socket during a catastropic break away - but I really don't care!

The other question I have is just where to secure the break away cable to the tow vehicle??? I've yet to find anything on my TV that is'nt in some way related to the hitch assembly and I often question whether or not that's really important. The safety chains assume that the receiver framework will still be intact in a break away - so it would take a "catastropic break away" - i.e. - the entire receiver would have to separate from the TV, or the safety chains would have to break, before the trailer brakes would activate. I can see that happening in a collision involving the TV and the trailer (---at which point who cares what happened first?) but how common would it be for the receiver assembly to fail simultaneously at all of it's connecting points while in a normal towing mode??? Likewise, if the safety chains aren't capable of restraining a runaway trailer (---one that has jumped off the ball---) what good are they??? I have every confidence that, aside from a buggered up tongue jack and damaged propane tanks, my TV would be capable of maintaining control of the trailer if it jumped off the ball and the chains picked up the load. That's another reason I like towing with the dually. I will admit that if one side of the receiver assembly broke free it might lead to loss of control - but that wouldn't have anything to do with the safety chains or the break away switch.

[ROBERTSUNRUS]

Originally Posted by Excella CM

Another parameter for break away cable length concerns newer high-tech electronic brake controllers. Since activating the break away switch with umbilical connected to the TV can damage the controller, I would seem prudent to make sure the length of the cable is adjusted so that during an unhitching incident, the umbilical comes out first.

Hi, I'm with Cracker; If my break away cable got snagged on something and destroyed my brake controller, I wouldn't be too happy. But in the event of a trailer disconnect and possible accident in progress, let the brake controller burn. [my opinion]

[slowmover]

Likewise, if the safety chains aren't capable of restraining a runaway trailer (---one that has jumped off the ball---) what good are they???

There is a thread here specifically about safety chains -- including US DOT regulations -- and the simple answer is that EACH CHAIN must be able to handle the trailer weight.

A breakaway line "loop" can be attached to the frame, with the above proviso it be in such a location that the cable is neither too long nor tangles itself, etc.

[pauly g]

My beakaway cable is longer than my chains, but I don’t have any real reason for this length. I have wondered how things would play out if the AS ever came loose from the TV. Doesn’t it seem that once a properly weighted tongue hit the pavement that the AS would stop very quickly even without the brakes? Maybe the requirement for a breakaway switch takes into account variables such as a trailer without any tongue weight, or one with front wheels like some semi rigs have. I also wonder if a loose trailer with suddenly activated brakes would be more dangerous to the traffic behind the incident than one that scraped itself to a stop.