Break-away Cable?

Ron Gratz addressed the breaking strength of the chains many moons ago but I don't have the exact thread to give a link.

One thing that hasn't been mentioned yet is the fact that, on most heavier trailers like many here tow, applying full braking force will not result in a huge jerking action at highway speed but usually just a strong slow down. The magnets strength is just not strong enough to jerk the trailer strongly in most cases. I don't know if disk brakes will jerk since I have never driven a trailer equipped with them.

Dodge Guy,
I knew someone was going to jump in on the spelling of Cummins. I spotted my error earlier but was too busy to correct it at the time. It is done now. :)
Barney

mowermech wrote:
Something I never see mentioned in these discussions is the breaking strength of the "safety" chains (or cables).
Are they really strong enough to handle the sudden force of the trailer brakes being applied at full 12 volts? That is going to be quite a jolt on those chains or cables! Will they hold, or will they break at that small abraded place?
For that matter, when was the last time you inspected them to be sure they don't have any weak spots?
If you noticed a worn spot, did you replace the chain or cable, or did you just let it go?
Think about it...

You must have missed my post where I described the specs for the chains, discussed the often criticized single chain attachment point, and the anticipated maximum tension the trailer under full braking would put on the TV. IMO there are no issues with the areas you are worried about.

I can't remember the exact specs, but IIRC WRT breaking strength it includes some time frame at the breaking strength tension before a certain percentages of failure and with the expected very short duration of a disconnect scenario as I remember this time frame was multiples of that anticipated time frame. Finally, chains come in specific breaking strength values which are thousands of lbs apart so there is a fair chance that the breaking strength of each chain will exceed that minimums specified.

Larry

Something I never see mentioned in these discussions is the breaking strength of the "safety" chains (or cables).
Are they really strong enough to handle the sudden force of the trailer brakes being applied at full 12 volts? That is going to be quite a jolt on those chains or cables! Will they hold, or will they break at that small abraded place?
For that matter, when was the last time you inspected them to be sure they don't have any weak spots?
If you noticed a worn spot, did you replace the chain or cable, or did you just let it go?
Think about it...

dodge guy wrote:
I`m going by physics, which says that when you pull something there is resistance no matter what it is. If your setup properly there will be no problem coming to a stop with light braking. If you lay on the brakes then yes you will have problems.

There's also inertia and gravity. Going downhill?

the pin would get pulled right as the trailer would come uncoupled. - etrailer.com

Remember, the whole purpose for the break-away cable is to pull the pin on the trailer tongue so the battery on the trailer will automatically apply the trailer brakes. As I understand it, this overrides the brake controller in the tow vehicle. Regardless if the chains hold in place or not, break, or even the trailer goes over a cliff, once that pin is pulled, the trailer brakes locked as much as they can be. It's designed to stop the trailer as fast as possible, regardless if it's still attached to safety chains or not. It really has nothing to do with the safety chains or anything else. It's about stopping the trailer in motion.

A few weeks ago I pulled the pin on my trailer frame (hitched to the truck). My brake controller in the truck was completely useless as my trailer brakes were locked down. And in order to free up the brakes, I had to insert the pin twice.

LarryJM wrote:

mike-s wrote:

dodge guy wrote:
If he trailer comes off the ball it will be drug behind the TV, brakes on or not. Tapping the brakes with the brake pedal will actuate the trailer brakes so it won't be crashing under the TV. It's really a simple process that many like to make difficult.

Uh, no.

You got that right. Once you have any slack in those safety chains they can allow the trailer tongue to ver off centerline and once any TT brakes are applied if you even have any since assuming that the umbilical cord hasn't been yanked out or pulled apart during whatever hitch failure you had it will violently yank the rear of the TV one way or another and could result in loss of control of the whole shabang. I can't count the number of reports of folks attempting to control a trailer only on safety chains only to have that trailer rear end them since there is no good way to judge the decelaration differential between the TV and TT to ensure it doesn't go slack or worst rear end the TV.

In my tests of the TT brakes only slowing down the entire rig from freeway speeds lasts anywhere from 5 to 15 sec so this entire event is extremely short as long as those TT brakes are on full and you stay off both the accelerator and TV brakes.

I'm surprised no one has thrown out this "RED HERRING" about either the safety chains separating or the often used and IMO desired single attachment point of them on the trailer being weak and subject to failure. Just remember EACH SAFETY CHAIN is to have a breaking strength equal to the GVWR of the trailer and IIRC Ron calculated that the max tension on a full braking TT is around 75% of it's max GVWR the probability of a safety chain breaking in that 20sec or failure of that attachment point is unlikely and I would put my money on neither occurring over a SWAG otherwise.

Biggest probem IMO is that trying to change a person's existing belief is near impossible when they have already rationalized reasons why their existing belief is correct and are naturally unwilling to admit they have been wrong and are very unwilling to change that prior belief. My only hope in posting and trying to provide the best credible and authortative information I know of is that someone that has not formed a strong opinion is willing to listen to the alternative reasons that I might provide. This breakaway discussion along with the crossing of the safety chains are the two hardest areas to change already formed opinions on what the facts and correct information really is.

However, as I have already said here one can do what one wants since that's there right, but in this case learning from one's mistakes falls in the too expensive category at least for me and I'm going to go with the what I consider the best expert information and what I feel makes sense to me.

Larry

Yes it is just like that. How can you say you have experience with separation by saying "I used the brakes only and it stopped in 15 seconds". that doesn't have anything to do with a trailer hanging on the chains. Your opinion is just like mine, and opinion! I`m going by physics, which says that when you pull something there is resistance no matter what it is. If your setup properly there will be no problem coming to a stop with light braking. If you lay on the brakes then yes you will have problems.

It really is that simple! I`ll quote you and let you figure it out. "Biggest probem IMO is that trying to change a person's existing belief is near impossible when they have already rationalized reasons why their existing belief is correct and are naturally unwilling to admit they have been wrong and are very unwilling to change that prior belief. My only hope in posting and trying to provide the best credible and authortative information I know of is that someone that has not formed a strong opinion is willing to listen to the alternative reasons that I might provide. This breakaway discussion along with the crossing of the safety chains are the two hardest areas to change already formed opinions on what the facts and correct information really is."

I've never actually checked the length of my break away cable. Now I have one more thing to worry about.... ;)

mike-s wrote:

dodge guy wrote:
If he trailer comes off the ball it will be drug behind the TV, brakes on or not. Tapping the brakes with the brake pedal will actuate the trailer brakes so it won't be crashing under the TV. It's really a simple process that many like to make difficult.

Uh, no.

You got that right. Once you have any slack in those safety chains they can allow the trailer tongue to ver off centerline and once any TT brakes are applied if you even have any since assuming that the umbilical cord hasn't been yanked out or pulled apart during whatever hitch failure you had it will violently yank the rear of the TV one way or another and could result in loss of control of the whole shabang. I can't count the number of reports of folks attempting to control a trailer only on safety chains only to have that trailer rear end them since there is no good way to judge the decelaration differential between the TV and TT to ensure it doesn't go slack or worst rear end the TV.

In my tests of the TT brakes only slowing down the entire rig from freeway speeds lasts anywhere from 5 to 15 sec so this entire event is extremely short as long as those TT brakes are on full and you stay off both the accelerator and TV brakes.

I'm surprised no one has thrown out this "RED HERRING" about either the safety chains separating or the often used and IMO desired single attachment point of them on the trailer being weak and subject to failure. Just remember EACH SAFETY CHAIN is to have a breaking strength equal to the GVWR of the trailer and IIRC Ron calculated that the max tension on a full braking TT is around 75% of it's max GVWR the probability of a safety chain breaking in that 20sec or failure of that attachment point is unlikely and I would put my money on neither occurring over a SWAG otherwise.

Biggest probem IMO is that trying to change a person's existing belief is near impossible when they have already rationalized reasons why their existing belief is correct and are naturally unwilling to admit they have been wrong and are very unwilling to change that prior belief. My only hope in posting and trying to provide the best credible and authortative information I know of is that someone that has not formed a strong opinion is willing to listen to the alternative reasons that I might provide. This breakaway discussion along with the crossing of the safety chains are the two hardest areas to change already formed opinions on what the facts and correct information really is.

However, as I have already said here one can do what one wants since that's there right, but in this case learning from one's mistakes falls in the too expensive category at least for me and I'm going to go with the what I consider the best expert information and what I feel makes sense to me.

Larry

dodge guy wrote:
If he trailer comes off the ball it will be drug behind the TV, brakes on or not. Tapping the brakes with the brake pedal will actuate the trailer brakes so it won't be crashing under the TV. It's really a simple process that many like to make difficult.

Uh, no.

LarryJM wrote:

mike-s wrote:
Trailer will be much more stable if its brakes are on than not. Pin should pull before chains break (which they shouldn't) - otherwise you're just adding manual trailer brake control to what you have to do to safely slow down. You really don't want to stop the combo using just the vehicle brakes, with the tongue under the vehicle, or swinging from side to side on the chains.

It won't be like a parachute, like someone said, more like a drogue chute - trailer brakes slow the combo, while the vehicles steers and maintains control.

If you've ever pulled a vehicle with a tow strap, you'll understand - you want to keep it taught or you're going to get yanked around and sacrifice control.

CONGRATS MIKE .... your the one that IMO is starting to get the idea. I've often said the last thing I would want to do is to take one hand off the wheel to muck around with the manual TT brake control and jockey it to get the amount of braking you THINK might be right all of which assumes that your unbilical cord wasn't ripped out during the hitch failure and now have a trailer w/o brakes bent on rear ending you. I want BOTH HANDS ON THE WHEEL with my FULL ATTENTION to simply maintaining control of the vehicle bringing it to a stop as safely as possible. My biggest concern is to as I alluded to in another post in this thread is to keep my wits about me and stay off my TV brakes and simply forget about the trailer since it's going to do what it wants anyway and worry about what I have some hope of controlling and that is my TV and the safety of those there. The one saving grace is I run this scenario thru my mind several times a day when towing as a reminder and have often practiced just how quickly simply letting off the TV gas and applying full trailer brakes at say an initial speed of 50 t0 60mph the whole rig slows down below 20mph at which time things have slowed down to something that just might be manageable.

Larry

If he trailer comes off the ball it will be drug behind the TV, brakes on or not. Tapping the brakes with the brake pedal will actuate the trailer brakes so it won't be crashing under the TV. It's really a simple process that many like to make difficult.