How Towing Safety Cables Work

towing safety cables
Towing safety cables are a vital piece of towing equipment. See more truck pictures.
Photo courtesy Eastern Marine

If you're one of those people who always seems to end up on top -- your toast lands butter side up, you hit all the green lights on the way to work and your paper always smothers the other guy's rock -- you may not worry too much about the possibility of things going wrong. It's great to be optimistic, but there's also something to be said for being prepared.

Many people carry along a spare tire on long trips and keep an umbrella in the car in case it rains. Wherever there's risk, a good backup plan is called for. Towing should be no different. In the case of towing, that backup plan exists in the form of towing safety cables or towing chains.


If you're reading this article, then you probably already know the basics of towing. You know that the tow vehicle connects to the trailer with a trailer hitch receiver attached to a draw bar or ball mount secured with a locking pin. And you know that the ball on top of the ball mount, which determines the type of trailer you can tow, fits into the coupler on the trailer's tongue, the section of the trailer that reaches out to connect to the tow vehicle.

­But if you're one of those butter-side-up people mentioned earlier, what you may not know is that towing safety cables and towing chains are just as vital as any other towing equipment. In fact, safety cables are required by federal law in most states.

The reason for this is simple: Nothing's perfect. Despite the best preparation, there's always the chance that some part of your towing setup could fail. If the trailer were to get disconnected from the tow vehicle's hitch somehow, you'd be looking at a huge mess. Loss of money, time and property would be the least of your worries -- you could also be endangering your life or someone else's. Learn how towing chains and safety cables could prevent such a disaster on the next page.



Using Towing Safety Cables

towing safety cables
When securely fastened under the trailer tongue, towing safety chains keep your load from crashing to the ground.
Image courtesy Miller Electric Mfg. Co.

Whether using towing safety cables or towing chains, it doesn't really matter as long as you use one of them consistently and properly. Sometimes the term "safety cables" is used to refer to either one, but the primary difference between the two is pretty self-explanatory: Safety cables are durable cables, whereas safety chains are made of heavy-duty metal links.

­The purpose of both pieces of towing equipment is to catch and support the load of the trailer if it gets disconnected from the tow vehicle. By crossing the chains or towing cables under the trailer coupler and attaching them to the tow vehicle with hooks, the safety cables act like a safety net in an emergency, catching the dislodged tongue.


While towing safety cables aren't designed to carry the fallen trailer across great distances, they do prevent it from crashing to the ground and spinning off into oncoming traffic. They give the driver enough time to pull over safely and figure out why the load came undone in the first place.

The most important thing to consider when picking out towing cables is the amount of weight you'll be carrying. That's because just like your tow vehicle and hitch, the safety cables are designed to carry a specific amount of weight. The capacity of the cables should exceed your gross trailer weight (GTW), the weight of the loaded trailer. Like trailer hitches, towing safety cables come in a variety of classes ranging from Class I (2,000 pounds (907 kilograms) GTW) to Class V (10,000 pounds (4,536 kilograms) GTW).

Another important thing to consider when setting up your safety cables or chains is the type of hook you want to use to connect them. S-hooks (metal hooks curved like the letter 'S') are a common option, but there are also slip hooks and quick links which close shut. Again, it doesn't really matter which you choose as long as you fasten them securely so they can't bounce loose, rendering your safety net useless. If you opt for the S-hooks, it's recommended that you also use rubber keepers to keep the hooks from bouncing out.

If your tow vehicle or trailer doesn't already have a place to connect the safety cables, you'll need to weld on a safety chain loop or bracket as a secure point of attachment. Again, make sure you pay attention to the equipment's class -- using only a Class II safety chain loop to tow your 5,000-pound (2,268-kilogram) boat won't do you much good.

After you've made sure the cables are securely attached to both frames, you'll also want to check to see that they've got a little Goldilocks action going on -- not too tight and not too loose, but just right. In this case, "just right" means not so tight as to prevent you from making a full turn but not so loose as to drag on the road. Too much slack in the chains could prevent them from doing their job.

So while it wouldn't be terribly catastrophic if some of you happy-go-lucky people were to drop your toast butter side down once in a while or occasionally catch a red light, towing is not an area where you want to be on the losing end. Towing safety cables and safety chains are part of a smart backup plan, whether they're mandated in your state or not.


Lots More Information

Related HowStuffWorks Articles

More Great Links

  • National Highway Safety Administration: Towing A Trailer


  • Cook, Miles. "How To Tow a Trailer." (Oct. 7, 2008)
  • "Safety Chains/Cables & Hooks." Eastern Marine Trailer Parts Superstore. (Oct. 8, 2008)­=217
  • Smith, Bruce W. "The Complete Guide to Trailering Your Boat: How to Select, Use, Maintain, and Improve a Boat Trailer." McGraw Hill. 2007.
  • Strickland, Jonathan. "How Trailer Towing Safety Works." HowStuffWorks. Sept. 30, 2008. (Oct. 8, 2008)
  • "Towing a Trailer: Being Equipped for Safety." National Highway Traffic Safety Administration. U.S. Department of Transportation. April 2002. (Oct. 7, 2008).
  • "Trailer Towing Safety Precautions." Miller Electric Mfg. Co. (Oct. 7, 2008)