Threading Breakaway Cable Through Safety Chains?
 

My brother-in-law has the breakaway cable threaded through his safety chains. I questioned him on this and he said the dealer in Montana said that there was a state law that it had to be done that way.

I think it's crazy. I pointed out that the safety chains would engage and tighten long before the breakaway cable would. The trailers brakes would never engage. He also had the breakaway cable attached to the hook of the safety chain, not to the hitch itself.

Thoughts?

I can see several ways.. the hitch/chains could fail.. and the brake cable/switch not be pulled.

I really doubt that that is a MT law.
The breakaway cable should be setup to engage the trailer brakes in the event of hitch/ball failure and separation from tow vehicle. I've read arguments for both having it pull the pin before full safety chain extension and for only being pulled on hitch and chain failure (cable longer than chains). I prefer the cable shorter than chains setup. Also the cable should not be connected to the hitch in any way, that is one of the items it serves to cover in the event of failure, the cable should clip to the tow rig frame/bumper and not the hitch.
Safety chain hooks openings should also face the rear vs facing forward.

Never heard of a regulation for this, but on my last trailer the breakaway wire was a hair too long so I threaded it up through the coupler pin just so it doesn't drag on the ground. Never really thought about what should engage first, safety chains or breakaway switch.

Opinions on the Internet are all over the place but I would say 60% of the posts I can find on the subject say the chains engage first and the breakaway cable engages only if the chains fail. I think that assumes that you still have the 7 pin cable still attached and working so that when the tow vehicle's brakes are engaged the trailer brakes also engage. Otherwise, when the tow vehicle engages its brakes the trailer is going to slam into the rear of the tow vehicle.

You have me a little confused

when the trailer brake-away cable is pulled, the trailer brakes goes Full ON.. using the trailer battery...

There are two schools of thought:
1. Breakaway cable engages before the safety chains have to "catch" the tongue. In this case, the breakaway cable has to be shorter than the safety chains.
2. Safety chains engage before the breakaway cable. The only way the breakaway cable engages is if the safety chains fail. The breakaway cable is longer than the safety chains.

For scenario 2 above, assuming that the 7 pin cable (brakes, tail lights, turn signals, etc) has also come loose but the safety chains are still attached, if the driver presses the brake pedal the tongue is going to slam into the rear of the tow vehicle because there are no brakes engaging on the trailer.

The crowd I run with replaces one of the license plate bolts with an eye bolt and attaches the break-away to the eye bolt. We also keep the cable clear / free of the trailer rigging.

Not going to argue whether Montana requires the break-away to wrap through the chain, but do agree with commentary where this can cause failure of the break-away in a scenario where the chain 'captures' the cord and snaps it prior to the pin coming out.

Another thing to look at as multiple trucks/vans pulling multiple trailers. different attachment points mess it all up. I need to put a new longer electrical cord on the small bumper pull car trailer. My Dad can pull it with his van and w/d hitch. I can pull it with my truck and my B&W adjustable triball. I cannot use my truck and the w/d hitch as the lights come unplugged on a tight right turn, of course this was noticed when needed to be used :-arrgh all this goes away if you assume only ever 1 tow vehicle.

Yep, I did a real nice neat job rewiring my small utility trailer that used to only follow my old Chevy and Honda CR-V around....Then I had to tow it with my EXcursion, and the EX's hitch mounted plug socket required me to make up a jumper harness as the other two vehicles both had loose wires leads that reached back to the trailers short plug. :-X19

Just kind of mulling this over because it sounds like the kind of thing without a solid answer. If chains first or second is the issue does this mean fivers should have chains. Just wondering. :)

Steve

Sure why not? watched a semi drop a 53 footer in the middle of the highway.....

I don't know if they should. I know they don't. Seems like anything that drops off at speed is not going to make for a happy ending, but wondering how often does that actually happen. :)

Steve

More often than you think with pull behinds. A careless driver can fail to seat the ball up inside the coupler, push the latch forward and lock, thinking they are secure. I know of a driver that recently did this and made it 150 miles before the coupler came off the ball.
Chains should be crossed under the tongue in order to catch it if it should come off the ball. This is to prevent “pole vaulting”. If the brakes were to engage with the truck still moving forward the tongue could be pulled clear of the cradle formed by the chains.
If the trailer and truck completely part company, the brakes of the trailer will (hopefully) slow the camper enough to minimize damage to the others nearby and secondarily the trailer. As mentioned, the breakaway cable should be attached to a part of the truck that can not come off. Finally, routing the cable through a clevis pin or padlock on the coupler is a good way to prevent chafing or damage to the cable.
Fiver breakaway cable should not be secured to the hitch, including the release lever. It should be attached to the bed itself, or a tie down or similar. Above the bed rails are not likely to fail catastrophically so are an acceptable anchor point.
FMCSR 393.43 (d) indicates brakes are to be applied immediately and automatically for 15 minutes upon breakaway. As long as the chains are supporting the tongue the trailer has not broken away, it is unhitched.

So where are the actual statistics? I am betting losing a trailer is a rarity rather than a commonality. And if it is commonplace why do fifth wheels not have safety chains?

Just wondering,

Steve