A. for coupled doubles and triples, be sure that the pintle hook is in the open position A. hand valve Watch the wording of the question AND the answers A safe driver will look for all of the above. The rear trailers shut off valves should be closed and the front open to allow air to the D. Make sure the spare tire is secured, if it has one. The DMV doubles triples practice test will examine your knowledge of pulling double/triple trailers, coupling and uncoupling, inspecting doubles and triples, and checking air brakes. It's a fifth wheel, not a sixth wheel. Why should you not use the trailer hand valve while driving? Air pressure is sent from the air tanks to the brakes by relay valves. You must steer gently when pulling trailers. In double and triple trailers, the trailer air supply control should pop or _________ when air pressure drops into the range of 20 to 45 psi. What three methods can you use to secure a second trailer before coupling? A. open Question 3 Explanation: All of the above. If you want to couple a second trailer to your combination vehicle, secure it by using: The crack-the-whip effect that troubles trucks with trailers is most likely to cause a tip over: You are driving on a slippery road during the day. The Doubles and Triples written CDL Exam is required for your doubles and triples endorsement. There is no obligation whatsoever. Slow to a safe speed before entering the curve, then coast through the curve. Only a certified diesel mechanic can check this. ), a 15 year truck driving veteran, in January 2007. Allow much more space than is needed for ideal driving condition. A The converter dolly air tank drain valve on coupled double/triple trailers should be: Closed. A bent or damaged kingpin on a coupling should be? The converter dolly air tank drain valve on coupled double and triple trailers should be: A. open B. closed C. partially opened B When inspecting coupled doubles and triples, make sure the pintle hooks are: A. secured to the safety pins B. in the open position C. latched C Which of these is true? The tanks will hold enough air to allow the brakes to be used several times even if the compressor stops working. To do this without wheels chocks you should: Supply air to the trailer air system with the tractor and then disconnect the emergency line. C. back up slightly and make a visual check of the coupling, You are driving with double trailers and must use your brakes to avoid a crash. 27. A. closed; latched 8. some large trucks have curved (convex or spot) mirrors. When connecting two trailers the converter dolly is connected to the rear trailer first. When you go to the rear of the last trailer, what should you do to complete this check? [Penalties Applying to Any DUI Conviction; Driving Under the Influence of Drugs or Alcohol (The "DUI" Law); Section B-7 Alcohol, Other Drugs and Driving; Tennessee Comprehensive Driver License Manual]. What is most likely to happen if the trailer protection valve of a double or triple trailer does not function correctly? You will not be tested on uncoupling twins unless you want to get a double/triple trailer endorsement on your license. When turning a double or triple at an intersection, the turn often cannot be completed without swinging wide. the trailer will be raised slightly when the converter dolly is backed under it the best way to keep brakes from getting too hot while going down long grades is to : go slow and use only light, steady pressure on the brakes you are driving a 100ft truck with double trailers at 30mph. The rear trailers shut-off valves should be closed and the front open. For emergency braking you should: C The emergency line valve open and release air C. 3, You are doing a walk around inspection of a double or triple trailer rig. Speed for other vehicles is often too fast for a multi-combination unit! Any time you have to C door. the crack-whip effect that triubkes trucks with trailers is most likely to cause a tip over when. Do converter dollies have spring brakes? you should avoid traveling next to others when possible. axle will have spring brakes due to the weight of the unit. You need to brake in order to regain control. Which trailer should come first behind the tractor? B. you can almost always stop more quickly than you can turn The pressure in the service line tells how much pressure the relay valves should send to the trailer brakes. Terms in this set (43) Converter dollies are used to connect: A tractor-trailer combination to another trailer. If this lamp is illuminated and does not go out, In this order, the shutoff valves at the rear of front trailers, the rear of the last trailer and the converter dolly air tank drain valve should be? You must treat a flashing red signal as you would treat a STOP sign. re-couple, You can if you want to, it does not matter. How much space should be between the upper and lower fifth wheels? These trailers have no parking brake. Those that do not have spring brakes have emergency brakes that work from the air stored in the trailer air tank. you should check the trailer height before connecting a converter dolly to a second or third trailer. The couplers have a rubber seal that prevents air from escaping. Safety chains secured to trailer (s). Your vehicle is so long that you must swing wide to make the turn. Which is most likely to tip over: retrovirus $_____________________________$. You are driving a 100-feet truck with double trailers at 30 mph. The crack the whip effect that troubles trucks with trailers. The crack the whip effect will topple the rear trailer first. Clean the couplers and rubber seals before a connection is made. 0000004668 00000 n
All material on this website is copyrighted. Like a trailer, a dolly equipped with ABS will have a yellow indicator light on the left side. A converter dolly is If a converter dolly has spring brakes, you release the brakes by You have connected the converter dolly to the front semitrailer and then connected the rear semitrailer to the converter dolly. The Verge logo. These dollies will have a yellow lamp on the left side of the dolly Questions You Should Know For Doubles And Triples 1. The trailer height is right when: The trailer will be raised slightly when the converter dolly is backed under it. Time allowed (Requires timer add on). B But the brakes will hold only as long as there is air pressure in the trailer air tank. Park the rear trailer against another trailer, chock the tires and lock the trailer 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 Should the shut off valves on the rear of the first trailer be open or closed on a set of double trailers? With the red knob pushed in on the tractor dash, the service line should have air in it. You may be timed. By using this site, you agree to be bound by our Terms of Use, Privacy Policy and Cookie Policy, Copyright 2000-2023 MH Sub I, LLC dba Internet Brands. C If you do cross the air lines, supply air will be sent to the service line instead of going to charge the trailer air tanks. 0000001107 00000 n
Did you know you can fill out one quick form here on TruckingTruth and apply to several companies at once for paid CDL training? D You are driving with double trailers and must use your brakes to avoid a crash. B. you should avoid traveling next to others whenever possible A. always keep your vehicle to the right side of your lane You must check that all shut-off valves are in the open position except the ones at the back of the last trailer, which must be closed. Some large trucks have curved (convex or spot) mirrors. which of these statements about quick steering movements and doubles/triples is true? D A Be sure pintle-eye of dolly is in place in pintle hook of trailer(s). Each trailer and converter dolly has one or more air tanks. B. the emergency line valve open and release air A converter dolly is a piece of equipment designed to allow commercial trucks, such as semi-trucks, to pull a trailer. The number and size of air tanks varies among vehicles. D A good and safe driver will always look out for ______. You should avoid traveling next to others when possible. 7. your vehicle is so long that you must swing wide to make a turn. 0000008894 00000 n
Make sure the converter dolly air tank drain valve is closed. B. allow one vehicle length for every 10,000 lbs of gross vehicle weight The last trailer in a combination is most likely to turn over. On double and triple combinations, you must make sure that which of these is secure? How much space should be between the upper and lower fifth wheel? A You should keep at least ____ seconds of space ahead of you. 11 B. do not need to be checked as often as flat mirrors because they show a larger area inspection of all equipment. 1/3 For example: If you are traveling 60 MPH and it begins to rain, your suggested All of the above, 6. Allow more following distance. coupled to the rear of a tractor-trailer combination forming a double bottom rig, A coupling device of one or two axles and a sixth wheel by which a semitrailer can be Take special care when pulling two and three trailers. Should the pintle hook be latched or unlatched when backing a dolly under the second trailer? Remember however, that is just a suggestion. A converter dolly is still under the second trailer when you unlock the pintle hook. The front trailer in a set of double trailers is most likely to turn over due to the Crack-the-Whip effect. The lighter semitrailer should be in first position behind the tractor. The air lines will rupture To check air flows to all trailers, you should let air pressure reach normal then? On a triple combination, the shutoff valves at the rear off the middle trailer should be? Older trailers do not have spring brakes. Which of the following is true about loading cargo into double or triple trailers? D Make a sketch that explains this phenomenon in terms of a feedback loop . When driving doubles or triples how should they be driven to avoid rollover or jackknifing: 0000007487 00000 n
Converter dollies are connected to front trailers with a? . Compressed air usually has some water and some compressor oil in it. By clicking on "Sign Up", you agree to our Terms of Use and Privacy Policy. You are doing a walk around inspection of a double or triple trailer rig. When you are pulling trailers, which of the following statements is true about steering? What is likely to happen? Which is most likely to tip over: This will let the rear wheels roll again and keep the rear wheels from sliding. You should keep at least ____ seconds of space ahead of you. HK Extended Tank Drain Assembly Kit with 10 Inch Braided Steel Hose 1/4 Inch Drain Valve and Elbow Fitting for Air Compressor 4.7 (463) $1499 FREE delivery Thu, Mar 9 on $25 of items shipped by Amazon Small Business All Tool Depot Air Compressor Drain Valve Replacement for Craftsman Petcock 072-0001, 072-0006 (1-Pack) 4.2 (20) $649 All rights reserved Site Map. If you're only pulling one trailer, the shut off valves should always be closed or else the air will simply escape out the back of the trailer. A turn of the glad hand attached to the hose will join and lock the couplers. 0000007032 00000 n
The lighter trailer should be in the rear. When uncoupling doubles or triples, what is important to know about unlocking the pintle hook? Which of these is the correct answer? The converter dolly air tank drain valve on coupled double/triple trailers should be: You are driving a 100-feet truck with double trailers at 50 mph. 1/4 in. In order to receive your Doubles and Triples endorsement, it is required that you pass the state's official CDL written Knowledge exam. c. iron A dolly is like a very short trailer, with a ring hitch on the front and a fifth wheel on top. C Secure converter gear support in raised position. It is very important to keep the air supply clean. Visually check to make sure that the lead trailer is slightly higher than the center of If there are no dummy couplers, the glad hands can sometimes be locked together (depending on the couplings). will have a lamp on the drivers side. These mirrors: make things seem smaller & further away then they really are. TestPermit.com is not affiliated, endorsed, or sponsored by state agencies or any motor vehicle and any other departments in the United States, Canada, UK. Slow to the safe speed before entering, then accelerate slightly through the curve. You may not notice a major leak in the service line until you try to put the brakes on. If the converter dolly is close to your semitrailer, you should wheel it into position? Did you know you can fill out one quick form here on TruckingTruth and apply to several companies at once for paid CDL training? Converter dollies have spring brakes. A full trailer behind a truck Locking jaws closed on You have not finished your quiz. Usually need a glad hand converter C. slow to a safe speed before entering the curve, then coast through it, Which of these is NOT a good thing to do when driving on slippery roads? You can test that air is flowing to all trailers by opening? There are more things that can go wrong, and doubles/triples are less stable than other commercial vehicles. Also, this page requires javascript. For emergency braking you should: Use controlled or stab braking Converter dollies: Often do not have spring brakes The crack the whip effect that troubles trucks with trailers. A. countersteer C. use controlled or stab braking, The best way to stop any skid is to: A safe speed on a curve for a straight truck or a single trailer combination vehicle may be too fast for a set of doubles or triples. Converter dollies: paramount to safe driving. C A vehicle transporting hazardous materials is required to display placards where? To check that the trailer emergency brakes are working properly, you should pull out the trailer air supply control and? The best way to keep brakes from getting to hot while going down long grades is to: Go slow and use only light, steady pressure on the brakes. When uncoupling a rear trailer, you should remove some weight from the dolly by? Open. The individual voltage gains of the first two stages are to be equal, while the gain of the third is to be one-fourth of each of the first two. What's a converter dolly? They provide the air pressure used to operate trailer brakes. In order to receive your Doubles and Triples endorsement, it is required that you pass the states official CDL written Knowledge exam. What value of channel width must the design use? 0000001775 00000 n
C What is a converter dolly? None of the above, 2. High Road 2.0! Which of these statements about quick steering movements and doubles/triples is true? True False True If you want to couple a second trailer to you combiantion vehicle, secure it by using the: Trailer emergency air brakes. B You should hear air escaping, showing the entire system is charged. C. foot pedal, Which of these statements about managing space to the sides is true? Which diagram shows the best way to turn? That split second that you release the brakes will allow them to match the vehicles road A connection device of one axle used to disconnect a semitrailer combination vehicle 9 Questions You Must Ask, Decide if Truck Driving is The Correct Career Path, Do Not Sell or Share My Personal Information. Describe what the trailer air supply control does. Hook dolly to front trailer. Should the shut-off valves on the rear of the last trailer be open or closed? All ABS equipped units A CDL is required to drive any of the following vehicles: A vehicle with two separate parts - the power unit (tractor) and the trailer. To uncouple the rear trailer in a set of doubles, the shut-off valve at the rear of the front trailer should be: Closed. you are driving a 100ft truck eith double trailers at 50mph. Connect the Converter Dolly to the Rear Trailer: Test the coupling by pulling against the pin of the second semitrailer. Correct answer percentage. Their drawbars differentiate them. When does the "driver's manual" advise disconnecting the steering axle brakes to help keep the rig straight? Before you can supply air to the air tanks of a second trailer you need to: Open the shut-off valves at the rear of the first trailer and close the shut-off valves at the rear of second trailer. Air escape from the open valve B The service brakes slowly move to the fully applied position C The emergency line valve open and release air D None of the above 4. 0000010306 00000 n
Push the brake pedal as hard as you can and hold it there These dollies will have a yellow lamp on the left side of the dolly. A. fully lowered For emergency braking you should: May have poor traction due to bouncing and wheels lockup. Which of these statements about the handling of doubles and triples is true? Submit your email at the end of the test. You are visually checking the coupling of a converter dolly to the rear trailer. Pickup at South Loop. Why should you pull a dolly out from under a trailer before you disconnect it from the trailer in front? 5. Release Dolly breaks by opening the air tank petcock or if the dolly has a spring break, use the Dolly parking brake control . The dolly tow bar may fly up . B When inspecting the air brakes on doubles and triples, you wait for air pressure to reach normal, then push in the red trailer air supply knob. 2. Pull gently against them in a low gear to make sure the brakes work. C Each trailer and converter dolly has one or more air tanks. How can you test that air flows to all trailers? Please use the form below to contact our customer service or sales team. during normal operation the brakes of the double/triple trailer are controlled by : which of these will result in the best control on curves? good speed management says you should, may have poor traction due to bouncing and wheel lock up. Remember: The trailer air brakes are supplied with air using the emergency line (also called the supply line). You are driving with double trailers and must use your brakes to avoid a crash. Any single vehicle with a GVWR of 26,001 or more pounds, or any such vehicle towing another not in excess of 10,000 pounds. It is important to check the height of the trailer before connecting a converter dolly to a trailer. How many different ways of coupling and uncoupling trailer combinations are there? The dolly tow bar may fly away, possibly causing panic, and making it very difficult There is a school zone ahead. - Converter dolly air tank drain valve: CLOSED. 0000006195 00000 n
to re-capture it. and ensuring it is secure. C. use a light touch on the accelerator and brake pedals, For coupled double and triple trailers, all of the converter dolly shut-off valves should be: If your tractor protection valve doesn't work properly, then if an air hose starts to leak what could happen? Sometimes, metal tags are attached to the lines with the words service and emergency stamped on them. If the fifth wheel on a coupling is too far forward, the tractor frame may hit? [Flashing Signals, Traffic Signals, Chapter 5 - Signals, Signs and Pavement Markings, North Carolina Driver's Handbook], One component of the DUI sentence in the state of Tennessee is twenty-four hours of litter pick-up wearing clothing that says "I am a drunk driver." This section explains how important it is to be careful when driving with more than one trailer, how to couple and uncouple correctly, and about inspecting doubles and triples carefully. If the spring brakes do not release when you push the trailer air supply control, check the air line connections. They provide the air pressure used to operate trailer brakes. 7.3 Inspecting Doubles and Triples = Additional Things to Check During a Walkaround Inspection. You should keep at least _____ seconds of space ahead of you. This has the same value as the %%WRONG_ANSWERS%% Variable on the Final Screen. rear brakes will not work properly. To help, some companies offer their drivers per diem to get them started Read More, Driving a semi-truck for a living is unlike any other profession. When does the "driver's manual" advise disconnecting the steering axle brakes to help A Commercial Drivers License Overview, Trucking Terminology and Transportation Definitions. Shut-off valves (also called "cut-out cocks") are used in the service and supply air lines at the back of trailers used to tow other trailers. Make sure you can hear air escaping with the valve closed. 2. The puzzle: At the far left edge, the plates are in contact, so the path length difference between rays 222 and 333 is zero. What types of trailers can get stuck on raised crossings? S-cam brakes are the most common style brakes on large trucks today. A 360 degree area of awareness is B. open; latched This is CDL Doubles and Triples Test 3in our original Classic Mode. The converter dolly is an auxiliary axle with a coupling device. Related Question Question: What does this sign mean? cQ
220rd8bihuM#Om>G*Lz)g^\l9'A9/omf|b49U[@%jGT-QR6i. You should be sure the converter dolly air tank drain . Open the emergency line shut-off valve at the rear of the last trailer. The driver must yield the right-of-way to other vehicles when merging and when entering a highway from an alley. CDL Doubles and Triples Test Question and Answers 2023 [PDF]: Commercial Drivers License Doubles and Triples Endorsements Knowledge Test. Shut-off valves (also called cut-out cocks) are used in the service and supply air lines at the back of trailers used to tow other trailers. Always test the trailer brakes before driving with the hand valve or by pulling the air supply (tractor protection valve) control. Nothing will happen, but an in-cab warning indicator will let you know about the problem, It will cause the tractor protection valve to close and the trailer emergency brakes to come on, It will cause the tractor protection valve to open and the trailer emergency brakes to come on, When you try to put the service brakes on, air will quickly leak and will lower the air tank pressure, possibly activating the trailer emergency brakes, The emergency brakes will come on automatically as soon as a major leak occurs, Nothing, but braking power will be reduced, Air pressure will quickly leak away, even if you are not using the service brakes, Using a combination of the emergency air line and the service air line, Supply air will be sent to the service line instead of going to charge the trailer air tanks which means the trailer spring brakes will not release, Newer vehicles automatically detect if the lines are crossed and will auto-correct itself, Air will continue filling the air holding tanks until the tanks rupture from excessive pressure, Supply air will cause all brakes to release and the truck will roll freely without any braking ability, Trailers typically do not have their own air tanks, Designed to turn off the truck engine when a brake failure occurs, Used in the service and supply air lines at the back of trailers used to tow other trailers, Placed at each trailer spring brake and are designed to engage the emergency brakes when air pressure becomes too high, The yellow and red air control knobs located in the cab of a truck, Used to secure the trailer kingpin to the tractor 5th wheel, Caps which cover the valve stems on tires, A name for the yellow and red air valves in the cab of a truck, Coupling devices used to connect the service and emergency air lines from the truck or tractor to the trailer, Email Updates When New Articles Are Posted. 4. Converter dolly air tank drain valve: CLOSED Air lines supported and glad hands properly connected. if you have traffic on both sides of your vehicle and something is blocking your lane, a move to the right still be best. Never unlock the pintle hook with the dolly still under the rear trailer. Any trailer, 7. In normal operation, trailer service brakes should be operated by? 12, 3. Wait for air pressure to reach normal, then push in the red trailer air supply knob. There are two types of converter dollies. Use the dummy couplers when the air lines are not connected to a trailer. speed and start spinning again, in turn stopping your skid, All the listed answers would be correct. with the hand valve on, you should test the trailer brakes by opening the service line valve at the rear of the trailer. CDL License Requirements State By State. 1 True! Open the emergency line shut-off valve at the rear of the last trailer. When the road is dry What should you check for when inspecting the converter dolly? B The coupling between a rear trailer and a dolly should have a space between the upper and lower fifth wheels of? If the dolly is a two axle unit then 1 You must check that all shut-off valves are in the open position except the ones at the back of the last trailer, which must be closed. When testing the coupling of the double trailer the landing gears of the rear trailer should be: You want to hook your combination to a second trailer that has no spring brakes.