Where and How to Attach Safety Chains

What are the best ways to attach safety chains on a trailer?  That’s a simple question without a single best answer.  Don’t you hate it when the answer starts with an “It depends . . . “?  Unfortunately, it does depend on other things — like how heavy the trailer is, the construction type, and perhaps most important, your biases and priorities?

That said, there are definitely some things to avoid.  So, let’s look at some bad ideas and learn, then at some good ideas.  Learning good technique by evaluating the bad.  Ah, but First, the goals.

Why Safety Chains?

While this may be a dumb place to start, let’s give a quick nod to why we have them in the first place.  One, because it’s the law.  Two, because it’s part of being responsible when towing.  And Three, to compensate for our own oops’.  Read more in our article on Trailer Safety Chains.

The point of asking ‘Why Safety Chains?’ is to make sure as we attach them, we don’t thwart the reasons for having them in the first place.  If the reason for having them is to keep the trailer connected in the rare event that the hitch disengages, then we need to make sure the attachment method will do the job if we need it.  Unfortunately, that is the purpose of the article.  So many chains attach in ways that won’t accomplish the task if you need it.

Now let’s look at some bad ways to attach safety chains on a trailer.

Things To Avoid As You Attach Safety Chains

I did a few searches on Google and YouTube for attaching safety chains, and am flabbergasted at the things people are teaching.  It’s one thing to put the chains on, and it’s quite another to make certain the chains will work in the violent events they are there to help with.  Please, question what you see and hear — EVEN in this article.  If things are contrary to sound thinking, disregard them.

OK, let’s get on with it.  Let’s learn good technique by evaluating bad.  Here are some examples:

Where’s The Grinder?

Why is this NOT a good way to attach safety chains?

If the tongue of the trailer did come off the hitch, one strong possibility is the tongue would drag the ground.  The event can be violent, and often at speed, so if the tongue does hit the ground, it will immediately start grinding through whatever touches.  So, we don’t want something to hit that will dig in, for sure.  But we also don’t want to grind off the very thing that is keeping the trailer attached.

So, our First Rule to learn is:  Attach the safety chains so if they are required, they won’t be grinding themselves through.  That means attach chains somewhere other than on the bottom of the tongue.

In the photo above, the loops may be good — I don’t know about their strength (see below) — but not in the position shown.

Wimpy, Wimpy, Wimpy

The next BAD idea is a classic.  It’s so common, and it boggles my mind.  OK, many trailer owners won’t know the difference, but someone had to weld it on, and if they know enough to weld, then they should know enough to understand that welding changes the temper, and strength of the chain steel.

Steel is not just steel.  There are thousands of steel alloys, each with unique characteristics.  Yet steels change properties with high heating, rapid cooling, or working (like forging).  Steel is great — some alloys are pliable like a coat hanger, others are hard and tough like a hammer.  I don’t know the alloys for safety chain, but I do know the links are made for high strength and toughness.

While chains are really tough, heating them in welding reduces that strength, and there’s no going back.  Even though you can’t see much difference, the actual metal is now annealed, so it’s weaker.  Maybe it’s still strong enough, or maybe not.

Second Rule:  Don’t weaken the chain getting it put on, and attach safety chains to things stronger than the chain.  Basically, we want the chain to be it’s own weakest link (since of course we buy the right chain).  Hooks and attachments should all be stronger than the chain.

Of course, there are limits in this.  If the chain is overkill, then maybe it doesn’t matter.  However, if you bought a chain rated for your trailer, why weaken it?  Just consider the situation and don’t make a rookie mistake.

How Long?

How long should safety chains be?  Long enough that things won’t bind when turning.  Actually, that’s not very long.

Extra length does 2 things:  First, if the chains are ever needed, short chains make it much easier for control.  Long chains allow the trailer more freedom to yank back and forth, forward and back.  The tongue can dive under the car, etc..  If the safety chains attach (on the trailer and on the tow vehicle) close to the hitch, the chains can be really quite short.  See the photo near the top of this article.

The hiccup comes with the need to accommodate multiple tow vehicles, and the solution is adjustable length chains.  (Which is one more reason to NOT weld the chain directly.)  We’ll talk about that below.

Rule Three:  Make the chains as short as practical, and if possible, attach safety chains in a way that allows length adjustment.  If that’s not possible, use other ‘appropriate’ ways to effectively shorten the chain.  See info below.

Awkward!

While cables are a reasonable substitute for chains, they have one very important similarity.  Chains and cables only work in tension.  It’s super hard to “push” a chain, and they don’t have much strength if you “kink” them.  By their very nature, chains and cables bend easily, but they are strongest when dead straight.

Look at this photo and see if you can find 2 things wrong?  (There’s more than 2, but see if you can find 2.)

What’s Wrong in the photo?  1.  Hopefully you see the connection point on the tongue that will grind right off when it hits the ground.  2.  The cable connection is 90° from expected forces, so cables will immediately “kink” if violent force is applied.  A “kink” seriously weakens a cable — bent chain links as well.  3.  The bracket for attachment is weaker than the cables.  4.  The cables are much too long.

Rule Four:  Think about the direction of forces.  If chains jump into action, make sure things holding those forces are directionally correct.

Another Bad Idea

In the category of “Bad Ideas” we’d be remiss if we didn’t also point out the problems with twisting safety chains.  Follow the link to this Article on Twisting Safety Chains for more information.

Now The Good Ways To Attach Safety Chains

We’ve learned from some mistakes above, now it’s time to look at some much better ways to attach safety chains.

Bolt Through

Bolting chains is a mixed bag.  If you support the link and the forces properly, it’s a great way.  If you crush the chain, use a wimpy bolt, or bolt to a wimpy member, then it’s bad.

Here’s an application I like for my trailer.  The tongue is 3/16″ thick, and the chain allows a maximum 7/16″ diameter bolt.  Using grade 8 bolts with nylock nuts and a bunch of modified washers, the attachment is tough.

The 2 bolts are through, making the chains easily adjustable.  My chain loops under rather than being cut, but the portion under does nothing.  You can also see the breakaway pin switch on the one side just above the chain.

Does it follow the rules?  1)  It won’t grind chains on the ground.  2)  It doesn’t weaken the chain, and the mounting (grade 8 bolts of larger diameter than the chain material) is stronger than the chain.  3)  It’s easily adjustable, so chains can be short.  4)  Direction of forces are in line with the chain.  (I will note, however, if the tongue dives under the vehicle, the pull is backward.  Yet, with the breakaway, forces should not go that way.)

Here’s a one bolt version of the above method.

Bolt Tabs

Special tabs made for to attach safety chains are a great solution.  Unfortunately, these fail the adjustable paradigm, but if you don’t need adjustability, they’re fine.  You can also easily switch for longer or shorter chain if needed.

The tabs are very thick, and have a lot of surface area to weld to the tongue tubes.  One hole properly spaced allows one link sit against the tab for secure bolting.  Again, grade 8 bolts (in the biggest size that will go through the link).

Does it follow the rules?  1)  It won’t grind chains on the ground.  2)  It doesn’t weaken the chain, and the mounting (heavy steel tab with grade 8 bolts) is stronger than the chain.  3)  It does not adjust, so chain length will have to be set carefully.  4)  Direction of forces are in line with the chain.  Overall it does the job well.

Double Tab Bolting

Finally, a double tab with a pin or bolt.  This is a little more complicated to visualize, but it’s 2 flat pieces of metal with the chain between.  We attach the safety chain with a pin or bolt, and the tabs are far enough apart that the chain moves easily for re-adjustment.

Does it follow the rules?  1)  It won’t grind chains on the ground.  2)  It doesn’t weaken the chain, and the mounting (grade 8 bolts and double steel tabs) is stronger than the chain.  3)  It’s easily adjustable, so chains can be short.  4)  Direction of forces are in line with the chain.  This is a very robust design.

If you like this design, but want something configured, try out Link Lock.  Their product is similar in concept, but probably better in function.  (Note:  I really like their concept, but I have not been able to get a return call from them.  I spoke to someone a few times, but not the person who can answer technical questions.  Multiple promises to call back did not materialize.  Now the website looks like it’s unattended, so maybe they are not viable?  Let me know if you find out something.  I’d love to buy a set and try them.)

Another Pinned Product

Along similar lines as the one above, here is a product that also pins the chain.  It’s not amazing, but it is available to purchase.  Do a search.  I found something similar from a few different sources.  Since I don’t personally know any of the places, I won’t make a recommendation here.

Does it follow the rules?  1)  If it mounts on the side of the tongue, then it won’t grind chains on the ground.  2)  It doesn’t weaken the chain, and the mounting is solid when welded as intended.  3)  It won’t doe on-the-fly adjustment, but you can certainly change chains easily for the right length.  4)  Direction of forces can easily be in line with the chain.  Overall, I think it looks good.  You’ll just need to find the right size for the chain you wish to use.

More Good Ways

The above are a few good ways to attach safety chain, but they are not exclusive by any means.  There are lots of great ways — just ask yourself if they follow the rules.  Feel free to post comments below or send a quick blurb from our Customer Submission page if you know a good one.

There’s really no reason to have unsafe safety chains.

Watch the Tips Library for the next article on Good Ways To Shorten A Chain.

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