If you’re interested in operating a long combination vehicle, also known as an LCV, one of the most important skills you’ll need is coupling a semi-trailer dolly. While it may sound like a basic skill for any operator, it’s one of the most critical for pulling doubles or triples. It’s also required to receive your doubles and triples endorsement. Read on to learn about using a semi-trailer dolly with your rig.
Importance of Proper Coupling Procedure
The importance of proper coupling can’t be overstated. The inherent risks involved with an unsecured trailer vastly outweighs the risks of an unsecured load, and an unsecured load is one of the most feared mistakes that an operator can make. A trailer rollaway situation can cause serious injury and property damage. The responsibility lies exclusively in the hands of the operator to follow the proper steps to secure their trailer, but each year, mistakes or oversights lead to injury and death in truck and trailer runaways.
Coupling Your Semi-Trailer Dolly
When you’re new to pulling extra trailers, you’ll want to make sure you take it slow and follow each step you learned while receiving your doubles endorsement. There’s no downside to caution, especially considering the risk of damage to your truck, property, and other’s safety if you make a mistake.
Step #1 – Positioning the Semi-Trailer Dolly
Depending on the distance, there’s two ways to position your dolly. The more precise, but difficult, method is to wheel the dolly into position by hand directly in line with your kingpin. This is easier to do with some dollies than others.
The other option is to use the tractor to position the first semi-trailer, with the dolly already secured, in front of the second trailer. This way can be quicker if you’re planning on pulling a triple and already hooked up to the second trailer. However, it also runs a higher risk for damage and error. It’s often a better idea, after moving the dolly with the trailer, to unhook it and hand place it as mentioned above.
Step #2 – Connecting the Semi-Trailer Dolly
Once the second trailer and dolly are in place, you can back your first trailer into position in front of the dolly. From there, connect the dolly to the front trailer, taking care not to damage any lines or cables in the process. Double check that your pintle hook is locked and secure your converter gear support in a raised-up position.
After connecting the dolly to the front trailer, you should perform a check before connecting to the second trailer. This check should include:
- Confirm that trailer brakes are locked
- Confirm that wheels are chocked
- Confirm that trailer height is correct
The height of the trailer should be very slightly lower than the fifth wheel’s center. This will let the dolly raise the trailer when it’s pushed into place. If you’re planning on taking your endorsement written exam, keep this in mind! Trailer height is important and referred too frequently.
Step #3 – Connecting the Second Trailer
When all of the checks are complete, you can begin backing the semi-trailer dolly under the rear trailer. With the dolly in place, you should test the coupling by pulling against the second trailer’s pin. Confirm that the coupling is complete by making sure there’s no space between the upper and lower fifth wheel.
Once everything is safely in place, you can begin to connect the safety chains, light cords and air hoses. Make sure to raise the landing gear completely raised, then you can charge the trailers. Open the emergency line shut-off on the second trailer to check for air. If there’s no air pressure, you won’t have functioning brakes and likely need to bring your trailer in for service.
Tips for Coupling / Uncoupling
Be Careful with your Air Hoses and Cords
If you aren’t careful with your air lines, you could run the risk of potentially dragging them or the gladhands and cause severe damage. The same goes for any of the other hookups. It’s important to make sure they’re connected safely and securely.
Make Sure You Don’t Have to Reverse
Experienced LCV operators know the difficulties of reversing with multiple trailers. Even with short van trailers that may be easier to manage, it’s safer to hook up in areas where you can pull straight out when you’re done. If you think you’ll have to back up after coupling your trailers, consider moving somewhere else to perform the coupling. It may take extra time, but it will save you a lot of trouble.
Never Uncouple the Dolly When It’s Connected to the Rear Trailer
When uncoupling the semi-trailer dolly, remember to start back-to-front. If you unhook the dolly from the front trailer while it’s still connected to your second or third trailer, it will spring up and could cause serious injury. In addition to the risk to yourself, it will also make it more difficult to uncouple from the rear trailer.
Position Your Trailers Heaviest to Lightest
When you’re connecting multiple trailers, they should always be positioned in order of heaviest to lightest. This is true for doubles and triples.
Establish a Pre-Hook & Post-Drop Routine
The best way to avoid mistakes is to establish a routine that will keep you on track every time you hook and drop. This includes everything from checking your vehicle, checking your trailers, and checking your dolly. Safety should always come first, especially when you’re planning to operate an LCV; there’s no such thing as a small mistake when you’re towing that much cargo.
Do You Have Questions? Contact Semi Service Today!
If you’re looking to buying a semi-trailer dolly for you or your fleet and don’t know where to start, we can help answer your questions and guide you to finding the right one for you!
Contact us online or give us a call at (801) 895-4419 to get started today!
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