When making turns with the tractor-trailer, you
must allow for the overall length of the unit. Remember:
The tractor-trailer is hinged in the middle, and the trailer
has a tendency to cut the corners, rather than follow the
tractor. For this reason, it is necessary to make a wider
turn than when turning with a straight truck.
Figure 7-20.Right turn.
AUTOMATIC TRANSMISSIONS. Some
tractors in the NCF are equipped with automatic
transmissions. A low range can be selected to have a
greater engine braking power when going down grades.
The lower ranges prevent the transmission from shifting
up beyond the selected gears. Shifting an automatic
transmission incorrectly can cause serious damage to
the transmission; therefore, operators must study the
operators manual for techniques of shifting automatic
RETARDERS. Some tractors are equipped with
a retarder that helps slow a vehicle, reducing the need
for using the brakes. One common retarder is known as
the jake brake. Retarders reduce brake wear and
provide another means to slow down. Retarders are
controlled by the operator and are either exhaust, engine,
hydraulic, or electric.
Turning turn signals on well in advance of
starting the turn is extremely important. This
action warns other drivers that a turn is going to
be made and allows them to drive safely.
RIGHT TURNS. When performing a right-hand
turn, turn slowly to give yourself and others time to
avoid problems. If you cannot make the right turn
without swinging into another lane, turn wide as you
complete the turn, as shown in figure 7-20, view A.
Keep the rear of the tractor-trailer close to the curb to
stop any drivers from passing on the right. If you must
cross into the oncoming traffic lane when making your
turn, watch for vehicles coming towards you. Give them
room to go by or stop; however, do not back up for them,
because you may have a vehicle directly behind you.
Do not turn wide to the left as you start the turn to
the right, as shown in figure 7-20, view B, because a
following driver may think you are turning left and try
to pass you on the right. Remember: If you turn too sharp
while making a right turn, your trailer will ride up the
curb and possibly run over obstructions (fig. 7-21).
Figure 7-21.Incorrect right turn.