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Doubles/Triples Endorsement Test
Question 1 |
What three methods can you use to secure a second trailer before coupling?
All of the above | |
Park the rear trailer against another trailer, chock the tires and lock the trailer
door. | |
Park on level ground, put chock on the tires, and charge the air tank | |
Chock the tires, park on level ground and charge the trailer air tank if it does
not have spring brakes.
|
Question 2 |
Doubles and triples must be driven very smoothly to avoid rollover or jackknife
False
| |
True
|
Question 3 |
What should you check for when inspecting a converter dolly?
Make sure safety chains are secured to the trailers | |
All of the above | |
Make sure the spare tire is secured, if it has one | |
Make sure the converter dolly air tank drain valve is closed |
Question 4 |
Why should you pull a dolly out from under a trailer before you disconnect it
from the trailer in front?
The dolly tow bar may fly away, possibly causing panic, and making it very difficult
to re-capture it. | |
You can if you want to, it does not matter | |
The dolly tow bar may fly up, possibly causing injury, and making it very difficult to
re-couple | |
Because the book says so |
Question 5 |
Should the shut off valves on the rear of the first trailer be open or closed on a set
of double trailers?
Open
| |
Closed
|
Question 6 |
You should look into the back of the fifth wheel on a dolly to see if it is locked
onto the kingpin
True
| |
False
|
Question 7 |
A safe speed on a curve for a straight truck or a single trailer combination
vehicle may be too fast for double or triple trailers
False
| |
True
|
Question 8 |
What is a converter dolly?
A connection device of one axle used to disconnect a semitrailer combination vehicle
converting it into two trailers | |
A coupling device of one or two axles and a sixth wheel by which a semitrailer can be
coupled to the rear of a tractor-trailer combination forming a double bottom rig | |
None of the above | |
A coupling device of three or four axles and a fifth wheel by which a semitrailer can
be coupled to the rear of a tractor-trailer combination forming a hexagon bottom rig | |
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 |
Question 9 |
Should the pintle hook be latched or unlatched when backing a dolly under the
second trailer?
Unlatched.
| |
Latched.
|
Question 10 |
What do you check when making a visual check of coupling?
That there is grease between upper and lower fifth wheel. Locking jaws closed on
King pin | |
That there is no space between upper and lower sixth wheel. Locking jaws closed on
kingpin | |
That there is some space between the upper and lower fifth wheel. Locking jaws open
on kingpin. | |
That there is no space between upper and lower fifth wheel. Locking jaws closed on
kingpin. | |
None of the above.
|
Question 11 |
How can you test that air flows to all trailers?
Only a certified diesel mechanic can check this. | |
Charge the system and pump the brakes with the window down. | |
Disconnect the glad-hand at the front of the first trailer and listen for air flow | |
None of the above | |
Open the shut-off valves at the rear of the last trailer and listen for air flow. |
Question 12 |
When connecting two trailers the converter dolly is connected to the rear trailer
first
False
| |
True
|
Question 13 |
How do you know if your converter dolly is equipped with antilock brakes?
The dolly will have a red lamp on the left side | |
The dolly will have a yellow lamp on the right side | |
The dolly will have a red lamp on the right side | |
The dolly will have a yellow lamp on the left side | |
None of the above |
Question 14 |
Should the converter dolly air-tank drain valve be open or closed on a double
trailer combination?
Open
| |
Closed
|
Question 15 |
The front trailer in a set of double trailers is most likely to turn over due to the
Crack-the-Whip effect
False
| |
True
|
Question 16 |
Do converter dollies have spring brakes?
Yes.
| |
They all do, it is required. | |
Never.
| |
None of the above. | |
Some do |
Question 17 |
Should the shut-off valves on the trailers be open or closed on a set of double
trailers?
All shut-off valves should be closed. | |
The rear trailers shut-off valves should be closed and the front open. | |
The rear trailers shut-off valves should be open and the front closed. | |
The rear trailer does not have shut-off valves. | |
All shut-off valves should be open |
Question 18 |
How do you check to make sure the trailer height is correct before coupling?
The height is always the same. | |
Visually check to make sure that the lead trailer is slightly higher than the center of
the fifth wheel, so trailer is raised slightly when dolly is pushed under it. | |
Trailer height never changes!
| |
Visually check to make sure that the rear trailer is slightly lower than the center of the
fifth wheel, so trailer is raised slightly when dolly is pushed under it. | |
None of the above |
Question 19 |
When you're trying to correct a drive-wheel braking skid why should you stop
braking?
You need to stop braking because it's necessary for you to speed up | |
None of the listed answer | |
This will let the rear wheels roll again and keep the rear wheels from sliding | |
You shouldn't stop braking. You need to brake in order to regain control. |
Question 20 |
What types of trailers can get stuck on raised crossings?
Lowboys | |
All of the listed answers | |
Possum-belly livestock trailers | |
Moving vans | |
Car carriers |
Question 21 |
You should reduce your speed by about _____ on a wet road.
2/3
| |
1/4
| |
1/2
| |
1/3
|
Question 22 |
A vehicle transporting hazardous materials is required to display placards where?
On the back. | |
On the front. | |
All of the listed answers. | |
On each side of the vehicle |
Question 23 |
A good and safe driver will always look out for ______.
Vehicles turning into your lane | |
Brake lights from slowing vehicles.
| |
Vehicles coming onto the highway. | |
All of the listed answers. |
Question 24 |
If one air system is very low on pressure _______.
Only the rear brakes will not work. | |
Either the front or the rear brakes will not work properly or fully. | |
Nothing happens. | |
Only the front brakes will not work. |
Question 25 |
What is the most common foundation brake found on heavy vehicles?
Disc brakes. | |
S-cam brakes. | |
C-Clamps. | |
Wedge brakes. |
|
List |
About the Doubles and Triples CDL Test
The Doubles and Triples CDL test:
- 20 questions.
- You need 16 correct answers (80%).
- You may be timed. Time limit varies by state.
Double and triple trailers increase not only the operator’s risk of safety, but also the other motorists around him. Doubles and triples are more likely to overturn than other combination vehicles because of the “whip cracking” effect. Driving doubles/triples is also more dangerous in hot and cold weather driving, as well as on mountain roads.
A driver of a vehicle with double or triple trailers will have greater length and more dead axles to pull, increasing the likelihood of a wreck.
The topics with which you will want to be expertly familiar are:
- Inspecting doubles and triples
- Prevent trailer from rolling over
- Avoiding the Crack-the-Whip effect
- Complete inspection
- Manage space
- Coupling and uncoupling doubles
- Coupling and uncoupling triples
- Doubles and triples air brake tests
There isn’t as much information to be studied in the classroom or in the CDL manual regarding doubles and triples, so in-lot and on-the-road practice will help you pass this test.
Safety should never take second place, so know your stuff! What is a converter dolly? What three methods can you use to secure a second trailer before coupling? What should you check for when inspecting the converter dolly and the pintle hook?
