Breakaway Safety Brake Cable

[Jack O'Brien]

On August 18, 2004 Rich Boren quoted this from his brake manual:

"All actuators must have a way to apply the trailer brakes if the trailer separates from the tow vechile. The breakaway cable is connected from your actuator to your tow vechile. If the trailer separates from the hitch ball while towing, this breakaway cable applies the trailer brakes."

And he interpreted it to mean:

"If your saftey chain configuration doesn't keep the hitch off the ground when detached, the hitch will dig in, and rip the chain off and ye Ha....bad news. And if the breakaway cable is too short, it will activate the brakes unnecessarily, when the chain was doing it's job."

I understand Rich's viewpoint but, I'm not sure I interpret his brake manual the same as Rich. Although the manual is silent about chains, it clearly says: "If the trailer separates from the hitch ball while towing, this breakaway cable applies the trailer brakes."

There has to be a relationship between the cable length and the lengths of the chains for the brake lockup to work as intended.

QUESTION IS: WHAT IS INTENDED? Brakes to lock up while chains still attached or only if chains detatch?

[Chip Hindes]

We had this discussion once before after sombody posted that link to the boat which had come loose on the FL turnpike.

I remember reading a specific reference to the fact that the breakaway system should be adjusted it activates when the trailer falls off the ball, but assuming the chains are still attached.

Also, if you think about it for maybe three seconds, you'll realize this makes by far the most sense.

[Jack O'Brien]

Chip:

Yes, it makes more sense to me also. But the poll results are interesting, 50/50 so far with 8 votes. Maybe it depends on whether you tow in a red state or a blue state.

[richandlori]

I would want the chance to pull over to the side of the road with the rig still attached and under control. Why escalate the problem?

I had more than 3 seconds to think about it as I watched the trailer fade away in my rear view window detached from my tow rig when it COULD have simply been supported by the chain. If this isn't how the system should work (then forget the chain) and just let the brakes lock up, because if you think a rusted and corroded chain will hold with a brake lock-up......

Rich

[Chip Hindes]

Rich, I'm not sure what you're saying.

If your trailer comes off the ball, you want it to remain attached with the chains; that's precisely what they're there for. If the chains are rusty and corroded and might not hold the trailer, with or without the brakes locked, replace them.

If the tongue drops off the ball, that's one failure. If the chains hold and the brakes lock, I believe there's a fair chance you can bring the rig to a stop without much further damage or injury.

If the chains break, that's a second failure. Brakes locked or not, the trailer is on its own, and the chances of further damage and injury both increase quite a lot.

Picture the way this is likely to go down: Your trailer drops off the ball, the chains hold, but the brakes don't lock. If you realize what has happened, have the presense of mind and traffic and conditions allow it, there's a chance you may be able to allow the rig to coast to a stop without applying the brakes. Don't count on it. More likely, you'll realize something is amiss, and will instinctually hit the tow vehicle brakes, maybe really hard. The tow vehicle, now without the weight of the trailer pushing it, slows dramatically; the trailer from its momentum continues to move forward at its original speed. Until the chains pull it up short, at which point the trailer tongue gets whiplashed upward and slams into the underside of the tow vehicle, possibly doing some serious damage, maybe crushing or severing rear axle brake lines or even puncturing the gas tank. On some SUVs or vans, the bow of the boat may be through the rear window about the same time this happens.

[richandlori]

So you would rather pull a trailer with lock-up brakes down the road, and while pulling this trailer down the road by the saftey chains and locked up wheels, you wouldn't expect the chains to break no matter what their conditions? Let's not forget about the "quality" of the stock Mac trailer as we picture it being dragged down the road tires locked at 55 or realistically 65MPH.

I would rather NOT have the brakes lock-up if the hitch simple detatches from the ball. I think that would allow me more of a chance to get to the side of the road with the trailer still attached to my tow rig. I frankly wouldn't care about banging up my tow vehicle at that point (let the incurance Co deal with it) I am more worried about having the skidding trailer brakes cause a loss of control and someone behind me or beside me getting killed.

I guess I am saying that I believe the event of brake lock up adds to the risk of loosing your trailer (based on first hand experience). I would only want the brakes locking up IF the trailer is already loose from the tow vehicle.

Hey it's a free country so if you have a different risk analysis profile that leads to a different method, no problem. I'm sure which ever way it happens, who is "right or wrong" will be determined by 12 folks that couldn't get off of jury duty.


Having lost a trailer on the freeway at 65MPH and seeing what happens in the rear view mirror gives you a different prespective of risk profile.

It is also interesting to not that my boat/trailer came set up to operate in just this way, by having the appropriate lengths of chain and saftey brake cable.



Rich

[Chip Hindes]

It is also interesting to not that my boat/trailer came set up to operate in just this way, by having the appropriate lengths of chain and saftey brake cable.

No it didn't. It came with enough adjustment built in so you could set it up correctly regardless of your particular vehicle and hitch configuration. Setting it up improperly is strictly a matter of personal choice.

I prefer to take control my own fate as best I can rather than have a jury decide it. Again, a matter of personal choice.

[richandlori]

That's right Chip, the instructions that came with the Boat are sufficiently clear on this subject of properly trailering your boat and initial set-up, as to not end up in court in the event of a disaster ya right. As far as taking saftey into your own hands, I'm sure that argument will play well aginst the 12 year old kid in a wheel chair resulting from an accident. Be more realistic about the determining of legal liability and rid yourself of a false sense of security in doing what you "think" is right. That is what was intended by that comment.

I should also note that I was instructed of this technique in saftely towing by the California Highway Patrol during a eight hour course "safe commercial trailering class" which I attended as part of my regular saftey training, as my company drives a fleet of trailers around the western US.

So thanks for your personal opinions, but they should at least be noted as just that, an opinion.

Rich

[richandlori]

Maybe someone with a faster internet connection can help me search for this. But the regulations for Break-away trailer brakes I think is covered in section 393.43 of the "Federal Motor carrier Saftey Regulations and standard 11"

I was trying to find something more than.. "no I'm right....no your a boob, I'm right...no...Ect"

Rich

[Chip Hindes]

The lack of instruction on these matters in the Mac owners' manual is a fallback position of someone who might expect to be in court. Not a good fallback position.

You're posing this as if it's only a matter of time and luck before we are hauled into court. As I stated, my plan is not to be hauled into court at all. Having a trailer come off the ball is not the random equivalent of being struck by lightning on a sunny day. I expect that if I pay enough attention to safe equipment and its proper attachment, my trailer will not fall off the ball. If it does, I still contend that my chosen method is best for ensuring that I can bring the tow vehicle and trailer safely to a stop. If my plan fails and I end up in court, as a Registered Professional Engineer I have the legal standing to testify as an expert witness in my own behalf.

My opinions are, as you say, nothing more than opinions. They are however, reasoned opinions based on training and many years experience towing trailers with cars and trucks. Just as, I assume, are yours. My way isn't right, any more than yours is. Mine's just better. Badumpbump and nanny nanny boo boo.

49CFR393.43 isn't any help as far as I can tell. It states in part:

"Every trailer required to be equipped with brakes shall be equipped with brakes of such character as to be applied automatically and promptly upon breakaway from the towing vehicle..."

Although I found several references to safety chains and breakaway brakes in various state laws, in the CFR the safety chains are either part of another secton which I can't find, or are not covered at all. The latter may be likely, since Federal law is concerned only with interstate transportation, and 49CFR393 seems primarily oriented toward tractor semitrailer rigs, which by all the state laws I found aren't required to have safety chains.

Interestingly, the CA State DMV website covers safety chains and trailer breakaway brakes in successive paragraphs.

None of the 49CFR393, state laws or CA DMV website say anything as to the proper hookup and sequence of operation of these.

All of these use the words "breakaway" or "separation" when describing the conditions under which the breakaway system is required to operate. I suppose you could argue that a trailer which falls off the ball but is still held by the safety chains has technically not separated from the tow vehicle. I wouldn't.

[Rick Eggers]

I don't think I ever want my trailer brakes to "lock".
What I do want is for the brakes to be applied if the hitch comes off the ball, chains still attached, allowing a controlled decelleration, the way the system is intended to work.
Now, you guys can continue to argue about it all night long, I don't care.

Linda and I ran a race last Sunday. It's called the Dam Race, put on by the Barnum Bay Yacht Club on Lake Petenwell, Wisconsin. It's a point A to point B and back race, approximately 22 miles in length. We finished 4th out of 16 boats. All in all, a very good day, and the trailer didn't come loose from the ball on the way home.

Rick

[richandlori]

Rick,
if you don't want your trailer brakes to ever lock, then you should disconnect the "emergency break enguagement system" that upon being activated is a 100% apply break situation. That is exactly the problem I am attempting to FIX by having the emergency brake lock-up pull cord being LONGER than the saftey chains. Maybe chips and my back and forth have obsecured the issue we were trying to debate.

Rich

[Chip Hindes]

I'm not about to try it to find out, but I don't believe the Mac trailer braking system is capable of locking up the wheels under any condition, emergency cable activation or otherwise.

IMO, it doesn't matter either way. Given the choice of trying to bring the trailer and rig safely down with the trailer brakes locked up, or with them completely non functional, I'm still choosing the former.

[mrbill]

you want the brakes to be applied once the tounge comes off the ball.

Hopefully you will have chains crossed, and the tounge rests there. vs digging in and immediate jack knife / roll.

unless you have upgraded brakes to disks (vs drums) the brakes will not lock up. (or very very unlikely).

and even if they do, the trl will not just stop, maybe the tires will lock, but it wil take some time before the trailer stops.


the alternative is having a run away trailer. which could very likely cross lanes and kill some unsuspecting soul.

Once you have this kind of failure, just try to save lives, period. and dont think a trailer could not flip your tow vehicle. see it all the time.... in So Fla. not pretty....

But do as you wish, this is the way I've towed cars, for years. and you're right chains will snap if given enough sudden stress.

[ALX357]

#2) .. 'cause if it hits your head, it go "BOOM" ... ( just gybing )

#1) ..not that i would actually try to use such large chains, but just HOW BIG would the chains have to be (given using the strongest, most suitable kind of metal) to hold the boat ? Also, most standard hitches have chain-rings that would snap if the chain didn't, so how to fix that ?
maybe welding the super big chains on ....