Safety Chain Setup - Diesel Forum

NickKent · 06-19-2008, 05:55 AM

I've seen all kinds of length safety chain on bumper pull trailers. Dragging to too tight. What is the optimum length chain for a trailer? I always figured the longer the better as long as they didn't drag, but recently I'm thinking that if they can prevent the tongue from dragging on the ground if the trailer comes uncoupled that would be ideal. But the jack foot usually does that anyway.

jzellers · 06-19-2008, 06:38 AM

You're correct - they are supposed to be long enough so they don't bind when turning and still keep the coupler from hitting the ground. If possible it would be better to keep the jack foot from hitting the ground as well, but that's not always realistic unless the jack is the kind that pivots up out of the way.

Joe

LMJD · 06-19-2008, 08:19 AM

Quote:

......that if they can prevent the tongue from dragging on the ground

If you use two chains and cross-tie them, they will cradle the tongue if it came disconnected. (Left chain on the tongue goes to the right side of the bumper, etc.)

reba · 06-19-2008, 08:51 AM

Cross the saftey chains as stated.

You will only need 2 or 3 links of slack....................

fddriver2 · 06-19-2008, 08:54 AM

Quote:

Originally Posted by LMJD

If you use two chains and cross-tie them, they will cradle the tongue if it came disconnected. (Left chain on the tongue goes to the right side of the bumper, etc.)

I agree with crossing the chains. The other thing I do is, Get rid of the s-hooks and replace with heavy duty SS quick links..

With the quick links you can put them anywhere on the chain that you want...

fastzr1 · 06-19-2008, 09:12 AM

Quote:

Originally Posted by fddriver2

I agree with crossing the chains. The other thing I do is, Get rid of the s-hooks and replace with heavy duty SS quick links..

With the quick links you can put them anywhere on the chain that you want...

Are these quick links you refer to the ones that have a threaded barrel on them that you open and close to hook and disconnect them? I used those on an open trailer for years but with my 10K lb enclosed trailer, I haven't been able to find any that could support 10K lbs and still fit through the chain links.

fddriver2 · 06-19-2008, 10:10 AM

I live in the Fort Lauderdale, FL. area. I got mine at a Marine store, I don't remember what the capacity or size of them were, but together they were over the 7,000 lbs. that I neeeded...

Here is a link for links

Erigging - Catalog

Or you could do SS Anchor shackles....

http://www.e-rigging.com/store_produ...Choice=Catalog

Seems a little pricey, I know I paid less........

JADFPE · 06-19-2008, 01:44 PM

I use anchor shackles because of the weight ratings required. I also attach a rubber strap to the chain and the tongue to keep a minor amount of tension to keep the chains from dragging. But if the chains get tight in a turn, the extra chain is there and the strap will strecth. Agree 100% on crossing the chains.

Hope this helps,

John

NickKent · 06-20-2008, 06:45 PM

I of course always cross my chains. I guess some day I'll have to jackknife the trailers and set the chains up that way. Seems like I always get them a little too loose. But I figure better off loose than too tight. The s hooks really do blow. I don't think they even provide them on a trailer with more than 7k GVWR though. The large hooks with the quick link are nice.

Kaliburz · 06-20-2008, 11:47 PM

Finding the right rated parts is always a challenge. If finding something for 10K is hard, try finding something rated for 30K+. The safety chain/cable for a pup trailer on a semi should be rated for the load or close to it..... so they say.

Rick M · 06-21-2008, 07:11 AM

Something I would adamantly caution not to do is twist the chains to shorten them. I am constantly seeing utility trailers being hauled around with the slack being taken up by twisting which with a chain is the quickest way to induce catastrophic failure. Please figure out some other way to shorten the slack, it might save the other guy and he may be me.

Several years back a boat trailer came loose crossed a local 4 lane hwy and literally speared an oncoming driver. Granted the chains did not fail in this situation but it showed what a loose trailer can do to the innocent other driver. We knew the towing driver and her family well. She was simply ferrying the boat from one family member to another, backed the truck up, the loaner or borrower set the hitch on the ball, forgot or got distracted and did not lock it down nor chain it up, she trusting the guy to do it right just drove off when he said good to go. As she was tooling down the road she crossed one of the inevitable buckled up expansion joints and off the trailer went at 55-60 mph, the other drive never had a chance.

When talking about trailer towing safety this one event always comes to mind. I don't think the girl ever got over it.

LarryM · 06-27-2008, 05:57 PM

Quote:

Originally Posted by NickKent

I've seen all kinds of length safety chain on bumper pull trailers. Dragging to too tight. What is the optimum length chain for a trailer? I always figured the longer the better as long as they didn't drag, but recently I'm thinking that if they can prevent the tongue from dragging on the ground if the trailer comes uncoupled that would be ideal. But the jack foot usually does that anyway.

There are a couple of schools of thought on this, but this is how I have my TT setup.

1. Safety chains crossed and only enough slack to not bind in sharp turns.

2. Brake away lanyard attached to the vehicle and not attached to either the hitch or receiver. I also have by brake away lanyard shortened enough that it will activate in case of a TT to TV failure when the safety chains are tight. I check my system by blocking the TT and disconnecting the TT from the hitch and lower it onto the safety chains and then slowly pull the TV forward so it lifts the TT tongue off the ground. There is some disagreement on when the brake away switch should activate, but the following is how I think I would want it to work.

a. Hitch fails and chains tighten as TT slows and TV continues on and when chains are tight the safety lanyard is pulled applying TT brakes and I have done this drill in my mind many time and I would just let off the gas and try and keep control of the TV and let the TT do it's thing which it's going to do anyway. In the 5 or so seconds between the initial failure and if the safety chains brake I will be more concerned with getting the TV under control than worry about what the TT is doing. Some that disagree with this say they want the option of using the brake controller w/o the TV brakes to apply the TT brakes only, but unless you have a brake controller like I do you have to take one hand off the steering wheel to manually control the brake controller. IMHO that is the last thing I want to do in an emergency situation to have only one hand on the steering wheel.

3. S hooks are not used on any trailer more than a rowboat one and both the safety chains and hooking links to the TV should be rated at at least 2X and maybe 3X the GVWR of the TT.

Larry

Rick M · 07-01-2008, 10:29 AM

Larry,

What size chain would it take to be 2X the gross trailer weight of say a 10K trailer much less 3X? I'm not sure what anything over 3/8" is rated. Seems Grade 70 5/16" is work load rated ~4700lbs which is about the same as the grade 43 ?? 3/8". Would probably be talking about 1/2" or maybe 5/8" grade 80 to get to 20K. Don't think I have seen much of that hanging on the tongues of many trailers.

LarryM · 07-02-2008, 04:41 AM

Quote:

Originally Posted by Rick M

Larry,

What size chain would it take to be 2X the gross trailer weight of say a 10K trailer much less 3X? I'm not sure what anything over 3/8" is rated. Seems Grade 70 5/16" is work load rated ~4700lbs which is about the same as the grade 43 ?? 3/8". Would probably be talking about 1/2" or maybe 5/8" grade 80 to get to 20K. Don't think I have seen much of that hanging on the tongues of many trailers.

Remember what I said and that was

"chains and hooking links to the TV should be rated at least 2x and maybe 3x the GVWR of the TT"

notice the plural you have two safety chains and according to the following the min requirements are that each chain for TT must be rated at the GVWR of the trailer so and able to hold that load for 1 min. You don't have to have a WLL of each chain rated at the GVWR of the trailer since these are a one time use and 1 min in an emergency breakaway situation seems reasonable.

Trailer Safey Chain Requirements

Normally you will find that the normal WLL is about 1/4 of the breaking load and my trailer (GVWR is 7640) and uses 3/8 chain and a 5/16 clevis slip hook with latch along with a quick link with a working load of 2200lbs. I'm not positive of the breaking strength of the chain, but using the above link it should be between 7600 (grade 43) and 11,700 (grade 70). Also, each clevis hook should have a breaking strength of between 11,700 and 18,800. Not sure about the quick link, but it should be around 8,800 and is probably the weak link on my trailer. What was interesting is that the quick link was added by the dealer because my safety chains and clevis hook was too short. Assuming the factory chain was a grade 70 transport quality, my safety chain setup from the factory would be rated at 23,400 for the two chain which is over 3X the GVWR of my TT.

For your 10K trailer again using that link, depending on the quality of each chain will probably be rated between 11,700 and 26,400 which for two you will have between 23,400 and 52,800 rated strength in a breakaway condition for at least 1 minute.

I'm glad you asked the question since I think I'm going to go out today and pick up a couple of quick links WLL rated for at least 3,000 (approx breaking strength of 12,000) to better match what probably came from the factory in my safety chains.

Larry