Is Towing Really Safe?

by Bob (Ram) Muessig

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     The answer to this question is "Yes"...and "No". Let me explain.

     Towing a trailer can be dangerous to your emotional and physical health, as anyone who has towed a poorly-built, unstable trailer will readily testify.  A uncontrollable trailer can push you down unintended paths, break away and select its own direction, snake erratically all over the road, and perform spectacular feats -- land crosswise, on its side, upside down, whatever.  It will most likely end up being totally destroyed, taking you with it!

     But a trailer which is properly designed and correctly loaded can be a delight to own and tow.  But how do you know whether or not your trailer is in this category?  Pre-trip safety checks and a regular maintenance schedule will go a long way toward making your trailer friendly...assuming, of course, that its basic design is inherently sound.  Inspect your trailer thoroughly before each trip to make sure that its mechanical systems operate correctly. These pre-trip inspections will reveal which parts need attention before something happens.

     OK...where do we start?  How 'bout at the beginning -- at the hitch.  Be sure the hitch on the tow vehicle is adequate (plus 10% - 20% -- more is better in this case) to handle the net weight of the trailer.  A 5000 pound hitch just ain't gonna cut it if the trailer weighs 7000 to 8000 pounds.  Having your trailer goin' east on I-10 while you're headed north on I-17 because your hitch broke can be kind of embarrassing.

     Check the hitch carefully, especially if it's the "bolt-on" variety, and make sure all connections are tight.  Be certain that the big nut that holds the ball to the hitch is tight, too, for it will have a tendency to loosen, even with a lock-washer in place.  Trust me; it does happen.

     When you've checked that, you're ready to hook up to the trailer.  Once the coupling on the trailer is centered over the ball, lower it, making sure that it drops completely down on the ball.  Smearing a little grease on the ball will make this easier and will protect the surfaces that slide in relation to each other as you drive down the road.  When all is secure, close the latch (locking mechanism) and lock it with a small padlock.  That will prevent it from opening accidentally as well as deter vandals or thieves.

     Now connect the safety chains or cables.  These are very important and most states require two (2) of them to be used.  Hook them to the frame of the tow vehicle, not to the hitch, and be sure to cross them under the trailer's tongue (In the event of a break-away, the chains will catch the tongue and suspend it above the roadway).  Make sure that your chains are long enough to allow turns, but short enough that they don't drag the ground or allow the trailer tongue to be pushed forward into the fuel tank of the towing vehicle in case something does break (Sparks and gasoline, when combined, provide a spectacular pyrotechnic display which may be quite frightening when observed in one's rear-view mirror.).  

     OK.  Plug in your electrical connectors and test all your lights.  Now check the trailer brakes and make sure the break-away system is operating correctly.

     There are so many different types and makes of hitches available that it would be impossible to discuss all of them, so let it suffice to say that with 10% to 15% of the trailer's weight on the tongue, your tow vehicle should be level and so should the trailer.  Both units should also be level with each other.  Neither the nose nor the tail should be high or low.

     Ahhh...trailer sway.  What about it?  "Sway" is one of the most serious, dangerous, and frightening conditions you may encounter when towing a trailer.  Most well-designed trailers will track straight and true under almost any circumstances.  But sway lurks as an ever-present danger even so.  Many folks assume that the trailer is the sole cause of sway, but that's simply not true.

     There are several causes of sway.  For the tow vehicle...

          1)  Wheelbase is too short
          2)  Rear overhang is too long
          3)  Rear suspension is too soft
          4)  Rear-end weight is too much
          5)  Rear cornering stiffness is too low

     For the trailer...

          1)  Tongue weight is too little OR too much
          2)  Center of gravity is too high
          3)  Tongue length is too short
          4)  Trailer frame is too flexible
          5)  Trailer suspension is too soft

     Bear in mind also, that the wrong tires and/or improper inflation thereof may be critical factors.  Be sure the load rating of your tires is correct for your application and that all the tires are properly inflated.  And, one other thing...NEVER mix bias-ply and radial tires on the same vehicle.  Their characteristics are much too different and will adversely affect the handling of the trailer or tow vehicle.

     If you discover any defects in ANY of the above, correct them BEFORE you venture out on the highways with your trailer.

     "If I experience trailer sway while driving, what can I DO about it?" you ask.  Good question.

     There are basically two types of sway...MARGINALLY STABLE and UNSTABLE.  Marginally stable sway is a fairly constant weaving from side to side by the trailer -- it's always there but doesn't get out of hand.  This is often more of an annoyance than a threat.  As you increase your speed, however, the weaving from side to side increases as well, eventually leading to the second kind of sway -- Unstable!  This is where each side-to-side oscillation is wider than the one preceding it -- until the trailer either jackknifes or leaves the road, taking the tow vehicle, and you, with it.

     If you constantly drive at the upper end of the marginally stable region, you're begging for trouble.  I would say that you've got a death wish.  But if unstable sway begins, DON'T hit the brakes or try to steer out of it.  Hold the steering wheel steady and firmly and back off the throttle.  If you're lucky, your rig may slow into the stable area before anything really nasty happens.  Your best bet, however, is to think about all the factors that may cause sway and try to avoid them in your rig.

     I've often been asked about passengers riding in trailers and if it's OK.  Though it may be legal in some states, in MY opinion, it's a highly dangerous practice.  Consider this:  If your loading and/or tongue weight is marginal, simply having a passenger move from one place in the trailer to another may be enough to induce unstable sway.  Hence my advice -- NEVER, under any circumstances, allow any living creature, other than a plant, to ride in a trailer while it's under tow.

     Having said all that...enjoy your trip...and I'll see ya' down the road.

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