How to Avoid Jack-knifing Your Trailer

Jack-knifing your trailer is something you need to avoid as a truck driver, whether you’re slowly backing up or driving down the highway at a high rate of speed. Even if you’re moving slowly, you can still cause damage to your equipment—and if you’re on the highway, you can cause a major collision.

What is jack-knifing?

The term “jack-knifing” might come from the way the blades on a Swiss Army Knife rotate. Just like you’d guess, a pocket knife is made to swivel like that, but trucks and trailers aren’t.

There are two ways that a trailer jack-knifes:

  • Driving: a trailer might jack-knife when it skids. If mishandled, momentum will keep pushing the trailer forwards, while the truck will swing back towards the trailer. If your truck and trailer form an angle of 15 degrees or higher, you no longer have control of it. Chances of regaining control are slim at this point. Avoid this.
  • Backing: continuing to back when your trailer is at an angle from your truck can cause it to jack-knife. (This is one of the reasons that we put a lot of emphasis on safe backing in our classes.) To avoid this, you need to keep a cool head when backing and never allow your truck and trailer to get near a 90 degree angle. Always keep to the “S” formation and always keep your wheel rolling, never skidding or pushing.

How to Avoid Jack-knifing While Driving

1) Always know where all of your wheels are.

2) Make sure that your brakes are evenly set up on each side of the axles during your pre-trip inspection.

3) Any time you touch ANY brake, check your trailer to see whether it’s pulling left or right.

4) Avoid using your trailer spike (or trailer hand-valve, or Jake Brake) when you’re in the mud, on wet/icy/slippery roads, or travelling at a higher rate of speed.

5) Your trailer spike should only be used for braking in emergency situations on the road. On and off. Never hold it. Never use it for parking.

6) Make sure that you trust your driving and your ability to handle emergency situations should they arise. Make sure to find a good driving school in your area and get enough in-truck training that you feel confident handling your vehicle.

When to Use Your Trailer Spike

Your trailer spike MIGHT help to straighten you out in certain situations, but only when you’re:

  • Travelling at a lower rate of speed
  • At less than a 15 degree angle
  • All your brakes are evenly adjusted

If this was the case, if the trailer started to veer out of your lane, you could:

  • Pull on the trailer spike, then let go
  • The trailer spike will activate the service brakes on the trailer (and only the trailer)
  • The trailer will slow down, relative to the truck, and should straighten out

Do you have a question about handling your vehicle in an emergency situation, or truck driving in general? Please feel free to leave a comment below or send us an email. You can also sign up for one of our courses here.

Posted by: administrator ON Sun, April 5, 2015 at 7:30:00 am MDT    Comments (0)
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26526 TWP Rd 543

Sturgeon County, Alberta

(780) 668-9799