Make sure trailer height is correct. It must be slightly lower than the center of the fifth wheel, so trailer is raised slightly when dolly is pushed under.

When any vehicle starts to skid, you must act to restore traction to the wheels.

You should never disconnect the steering axel brakes.

For the safest handling on the road, the more heavily loaded semitrailer should be in first position behind the tractor. The lighter trailer should be in the rear.

Be more careful in adverse conditions like bad weather, slippery conditions, and mountain driving, you must be especially careful if you drive double and triple trailers. You will have greater length and more dead axles to pull with your drive axles than other drivers. There is more chance for skids and loss of traction.

Slow down to a safe speed, and downshift to the right gear before entering the curve. This lets you use some power through the curve to help the vehicle be more stable while turning.

One good rule says you need at least one second for each 10 feet of vehicle length at speeds below 40 mph. At greater speeds, you must add 1 second for safety.

You should brake in a way that will keep your vehicle in a straight line and allow you to turn if it becomes necessary. You can use the controlled braking method or the stab braking method.

Converter dolly air tank drain valve are closed, and make sure pintle hook is latched.

A converter gear on a dolly is a coupling device of one or two axles and a fifth wheel by which a semitrailer can be coupled to the rear of a tractor trailer combination forming a double bottom rig.

Release dolly brakes by opening the air tank petcock, or, if the dolly has spring brakes, use the dolly parking brake control.

Test coupling by pulling against pin of the rear semitrailer

Charge the trailer air brake system. Shut the engine off. Step on and off the brake pedal several times to reduce the air pressure in the tanks. The trailer air supply control should pop out or go from "normal" to "emergency" position when the air pressure falls into the pressure range specified by the manufacturer. Usually within the range of 20 to 45 psi.

If the landing gear is power operated, make sure there are no air or hydraulic leaks.

A triple combination vehicle has four units (not counting the converter dollies): a tractor and three trailers. You couple a triple as follows: 1. Couple the first trailer to the tractor the same way that you couple any combination vehicle. 2. Couple the third trailer to the second trailer using the method for coupling doubles (which will involve the use of a converter dolly). 3. Move another converter dolly into position. 3. Couple the tractor and first trailer to the second and third trailer using the method for coupling doubles (which will involve another converter dolly).

The trailer air supply control should pop out or go from "normal" to "emergency" position when the air pressure falls into the pressure range specified by the manufacturer. Usually within the range of 20 to 45 psi.

Wait for normal air pressure, release the parking brake, move the vehicle forward slowly about five mph, and apply the brakes firmly using the trailers hand control. Note any vehicle pulling to one side, unusual feel, or delayed stopping action.

The trailer air supply control also called the tractor protection valve control should pop out or go from "normal" to "emergency" position when the air pressure falls into the pressure range specified by the manufacturer usually within the range of 20 to 45 psi.

Park rig in a straight line on firm level ground

Converter dollies built on or after March 1, 1998, are required to have antilock brakes. These dollies will have a yellow lamp on the left side of the dolly.