Combinations weights

Industrial burgundy classic big rig semi truck tractor with extended cab for truck driver rest transporting fastened cargo on step down semi trailer driving on green highway road in Columbia Gorge

Hauling combinations, be it A-trains, B-train or C-trains, there are a few rules and safety procedures that simply must be followed to prevent dangerous and illegal situations that could very easily result in serious injury or death. For this article, we will stick with weights, but other factors will be covered in the future.

When pulling any combination units, the heaviest trailer MUST be hooked to the tractor and the lightest trailer must be the rear most trailer.  Dispatchers and planner may say otherwise, but they are incorrect.  This is a law, and it is spelled out quite clearly.  The reason is safety. If you had a heavy trailer behind a light trailer, the heavy trailer will, not might, it WILL cause the front trailer to wiggle from side to side, which will cause the rear trailer to wiggle more, causing the front to wiggle more, and before long, you’re folded up in the ditch. Even if both trailers are empty, the heavier one must be hooked to the tractor. As a rule, from heaviest to lightest are:

  1. Reefers
  2. Heaters
  3. Dry vans
  4. Step decks
  5. Flat decks
  6. Chassis

It should be obvious that the more axles a trailer has, the heavier it will be.

Best advice, is to weigh each trailer individually. That way you know for certain which trailer is the heavier one.  Do not under any circumstances go by the weight listed on the paperwork.  That is just the weight of the cargo, it does not include the weight of the trailer. If you have 15,000 lbs in a tandem dry van, and 14,000 in a triaxle reefer, it’s almost a guarantee the reefer will be the heavier trailer by about 3,000 lbs.

Don Taylor has been a professional driver since March 1985.  In 1994 he made the jump to driving tractor trailers, and has accumulated over 3.5 million miles, including over 4 years of driving turnpike doubles in Manitoba, Saskatchewan and Alberta.  He is currently hauling flat decks across North America.