Disclaimer Disclaimer This course should be reviewed to assure that the information conforms to recommended procedures, as well as to any federal, state or local laws regarding any facility s operation. The producer makes no warranty, expressed or implied, that the information in this course is accurate or appropriate for any particular facility s environment, or any individual employee s situation. Types & Uses On a tanker the contents will always be in motion since they can not be secured or tied down. The more your cargo moves the more it will effect your handling and nature of driving. 1
Types & Uses Your job as a professional driver is to make sure that you keep the motion of contents in the tanker to a minimum. Types & Uses Tankers are ideal for transporting dry bulk materials as well as liquids. Listed below are a number of dry bulk contents that are sometimes contained in tankers: Grains Dry cement Flour Sugar Plastics Some liquids that maybe transported by a tanker are: Types & Uses Petroleum goods Chemicals Food products Liquefied gases Asphalt Waste materials Water and even wine 2
Types & Uses There are two types of compartments a tanker can have. It can have one large compartment or can be divided into several compartments depending on the load. A tanker with one compartment is known as a clean bore unit. It can be completely open or it can also contain baffles that help to cut down on the content movement. This makes it easier to control the tanker. Types & Uses Clean (Smooth) Bore Tanker Baffled Tanker A tanker without baffles requires more driver attention as it allows more movement or cargo SURGE. Types & Uses Bulkhead Tanker A tanker that is divided into several compartments is known as a compartmentalized tanker. It is used to transport a different variety of cargo within the same tanker. 3
The first step in a safe operation is a thorough inspection of the tanker. There are additional requirements to be followed before during and after the pre-trip, in route, and post trip inspections. Your company may have special requirements according to what type of tanker you transport. It is important to understand the handling techniques of tankers in general. In addition to the specific characteristics of the tankers that you usually handle. Sloshing and surging are the terms typically used to describe the motion of liquids in a tankers cargo. As a driver it is your responsibility to control these movements to a minimum. Surge Slosh 4
A tankers liquid contents has a tendency to move a vehicle to the back, front or side to side when in motion. It is the drivers responsibility to understand this and take preventive measures especially in severe weather. There are three basic rules of physics at play that will help you to understand the movement of the liquids in your tanker and help keep it under control. 1.Centrifugal Force- It is what propels your load forward backward or outward based on your vehicles movement. 2.Momentum- It relates to the force or speed of movement. Once the liquid in your tanker begins to move it continues to move even during stopping. It will continue to move until the vehicle and tanker have been at rest for a certain period of time. 5
3.Inertia- When matter is without movement it tends to stay motionless and when it is in motion it continues to remain in motion unless acted upon by some outside force. Vehicle At Rest (Parked) There are other important things to keep in mind in addition to the three laws of physics: Observing the rules of the road 55 MPH Exercising your best hazard perception Defensive driving techniques The same driving techniques that apply to other tractor trailers or straight trucks are even more important to tanker drivers due to the fact that your load reacts greater to your movements. Load Reaction 6
It is important to be aware of how your movements will effect your loads movement. Which will also effect your ability to drive safely. -Acceleration Here are the three primary movements that will create sloshing and surging in your tank which can also effect the safe operation of your vehicle. Improper acceleration- Sudden acceleration causes your liquid to surge to the back of the tank quickly. Over acceleration can cause you to have an accident. Smooth acceleration will decrease cargo surge pretend there is an egg under the tanker accelerator pedal. -Turning Improper turning- Sudden turns changes your center of gravity causing your load to move outward quickly. When turning the load will move in the opposite direction and this sideways sloshing can cause your tanker to turn over if moving to fast. Load Reaction 7
-Turning Improper turning continued - When making a left or right hand turn make sure to use your signal early so that other motorist are aware and prepared. Slow down gradually so that you can prevent the amount of movement in your load. -Turning Improper turning continued - Avoid turning to fast or to soon. Turning to fast will make your load move more quickly and turning to soon can cause you to run over a curb and cause your load to start sloshing. Load Reaction- SLOSHING -Turning Improper turning continued - Reduce your speed to lower than posted limit when turning. Even traveling at a mere 20mph could cause you to tip over. Be cautious when entering and exiting ramps since they are banked and if traveling to fast the movement of your load could cause a disaster. 55 MPH Posted Reduce to 30 MPH 8
-Braking Improper braking- Avoid braking while making a turn. This will also cause your load to surge making it more difficult during a turn. Sudden braking causes the load to surge to the front of the tank making it difficult to accelerate and stop. It may also jar and propel your vehicle forward. This motion may cause you to rear end another vehicle at a stop light or stop sign. -Braking Whenever you come to a complete stop ALAWYS keep your foot firmly planted on the brake. This can help prevent cargo surge that may move your vehicle forward. Try to avoid stab braking as it will cause sudden surging of your load and is not safe. -Braking IT IS IMPORTANT TO MAKE NO SUDDEN MOVEMENTS! 9
-Elliptical When carrying a partially loaded elliptical tank or clean bore tank remember: The three primary movements will be greatly exaggerated. They have a lower center of gravity but the amount of unfilled space inside allows the liquid a greater amount of lateral movement. If they are between 25% to 80% loaded they are more likely to roll over. Potentially dangerous driving situations can be avoided if you remember to follow these simple rules: -Slow Down SLOW DOWN! make no sudden movements Exercise your best hazard perception skills Accelerate slowly Enter turns slowly And brake slowly SLOWING DOWN IS THE BEST WAY TO KEEP FROM LOOSING CONTROL OF YOUR VEHICLE Course Goals Jack Knife Figure 1. If you lock the steering axle brakes, the rig will move straight ahead regardless of the wheel angle. Figure 2. If you lock the drive axles, the rig will jackknife. Figure 3. If you lock the trailer axles, you will get trailer swing. 10
Course Goals Case 1. is the best situation although it's not really good, you can't steer. Jack Knife Case 2. is very bad, you will jackknife sooner or later if you lock your drivers regardless of what your steering axle is doing- even if you have your steering wheels pointed straight ahead. Road crown or left/right imbalances will get you if you slide long enough. Case 3. Like case 2., once you lock the brakes, you lose directional control at the axle, and sooner or later a sideways pull will develop that effects the directional stability of the vehicle. Course Goals Jack Knife The basic problem is that pneumatic tires only offer so much traction and if you use it all in braking, you haven't got any left to resist even slight lateral forces. If you can keep the axles from locking up, even 5% short of lock up, you can generally preserve directional stability and even some steering capability. But this can be hard to do without ABS, especially with unbalanced brakes or a poorly distributed load. Course Goals Jack Knife Bottom line: In an emergency situation-without ABS- you've got your choice of directional stability or maximum braking. If you dynamite the brakes you may lock some axles and get one of the problems listed above. Which axles, if any, lock depend on the condition of the brakes and the weight on each axle. Case 2. should be avoided at virtually all costs, if you jackknife you may rollover. Case 3 is a little better, it will take a little longer for trailer swing to get you into serious trouble, unless the trailer hits another vehicle when it swings out. Case 1. is the least dangerous, you can't steer much in a semi anyway. A hard steering maneuver will roll you. So: Don't back off or disconnect the steering axle brakes! You need them bad when your bobtailed and even when your deadheaded or fully loaded they are important. Steering axle brakes provide about 12% of the total braking of a loaded vehicle and you need all the braking you can get. 11
Course Goals ROLLOVERS: Rollover 1. The Problem: - Big rigs roll easily. You can put a number on the tendency that a vehicle has to rollover- the higher the better (safer). Full size cars are about 1.3, pickups are 1.1, Jeep type vehicles are 0.8-1.0. Fully loaded semis are about 0.4 or lower. A half empty tanker with a bad suspension might be 0.15! These numbers are the cornering "g's" required to roll the vehicle. No car can generate 1.3 g's in cornering but your rig can probably generate 0.4 g's going around a corner or in a variety of other maneuvers involving steering. If you go around a curve too fast, you will go over, but you probably already knew this. Here are some things you may not know: Course Goals ROLLOVERS: Rollover - You can go over in a curve without going to fast for the curve if your rear tires strike something (like a curb) while you're cornering. Articulating vehicles (5th wheel type) with rubber tires outrack when turning above a certain minimum speed, typically 15 mph. This is inherent to the vehicle and not the result of poor driving. Your trailer axle might be 2 feet outside your steering axle if you're pulling a long trailer. Picture this: You're coming down a freeway ramp, turning right ( a right hand curve). Your left front tire might be 1' inside the fog line while your outer left rear tire might be 1' outside the fog line. What's out there to trip you and turn you over? - You can probably roll your rig at speeds as low as 5 mph, especially on slopes or where a strong tripping influence is present. You can roll backing up if you're jackknifed. Course Goals ROLLOVERS: Rollover - Many rollovers happen when drivers try to return to the road after putting a tire off the pavement. You can rut in soft ground or catch a pavement separation here and go over. If you put a wheel off the pavement or even onto a paved shoulder that may have separations, straighten the rig out and bring it to a stop. Don't try to return to the road at speed. Get out of the rig, carefully inspect the site and determine that you can get back on the road without catching or tripping a tire before you move out again. If you do decide to drive it back on, return to the road as slowly as possible and at as shallow an angle as possible. The more steer you put in the easier it is to go over. If it looks too bad, call a wrecker! We are not kidding here, we know that thousands of drivers have gone off the road and come back without rolling the rig, but hundreds of others have also tried and died in the attempt. 12
Course Goals Rollover ROLLOVERS: -Treat any load that can move on you like a load of dynamite and drive accordingly. -Lane changes and similar road maneuvers can roll you, this goes double for double drivers and triple for triple drivers Course Goals Rollover The National Safety Council has determined that remaining in the driver's seat is the best chance for survival in the event of a rollover. To achieve this it is necessary that you utilize the seat belt and shoulder strap each time you operate the unit. Do not allow yourself to be influenced by the misconceptions that you are more susceptible to drowning or burning with a restraint device. Submersion and fire account for only one-tenth of one percent of all traffic fatalities Course Goals Rollover Your greatest protection is in the prevention of the rollover in the first place. Any turning movement must be made slowly and deliberately. Allow for product movement within the trailer. On long sweeping curves be alert to the load pushing the tractor. Your only defense is to slow your speed before entering the curve. Speed management and being aware of your situation is the key to preventing rollovers. 13
-Safe Zone Give yourself plenty of time and plenty of space when changing lanes and plenty of room to maneuver. Defensive driving and Proper driving techniques are skills that every driver must know and practice daily. Especially considering you are carrying a tanker. At all times try to keep a safe zone around your vehicle. Get into the habit of using your mirrors to continually scan the front, sides and rear of vehicle. -Safe Zone Typically while driving in the city you need to scan one block ahead, which is roughly 12-15 seconds. While on the highway scan ahead about ¼ of a mile which is roughly 12-15 seconds. Slow down while in bad weather due to slick roads and poor visibility which could make it difficult to avoid sudden movements. If you encounter extreme weather conditions. Pull over in a safe secure location and contact your dispatcher and wait it out. -Safe Zone Watch for unmarked or low clearance passages. Always second guess the amount of space in between your tanker and the over pass. If in doubt avoid the underpass and take another route. Be alert for new or recently paved asphalt or road construction at overpasses. 14
-Safe Zone Potholes and railroad tracks can jostle your load and send it into motion. Hazmat loads are required to stop at all railroad tracks. Stop within 50ft and no less than15 ft away from the tracks. -Safe Zone Always look both ways when crossing. Never shift gears or stop when moving over railroad tracks. Always scan intersections and never assume that you have the right away. -Passing Remember that passing is always dangerous. Ask yourself if it necessary and make all your decisions based on safety. These are times to never pass: On a bridge Traveling uphill At a intersection Around a curb Over a railroad crossing 15
-Lane Changing Always make sure the other drivers are aware of your intentions by signaling early Us your mirrors to scan to the side and rear of your vehicle Make sure you keep ample space between you and the car in front of you to prevent a collision while looking in you rearview mirrors. Remember to use your mirrors when merging. Continue to scan the roadway for upcoming hazards. -Hazards Road hazards relate to the road itself: Potholes Slippery surfaces Debris Sharp turns -Hazards User hazards have to do with others with whom you share the road with: Skaters Bicyclers Motorcycles Recreational vehicles Other vehicles Pedestrians 16
-Hazards There are some hazards that you can anticipate and plan for such as road construction and crossing zones. However there are some hazards that you can not plan for and may catch you by surprise. Such as erratic driving, debris from other cars, a pedestrian running across the road or even a sudden gust of wind You must learn to observe hazards and plan before they happen. You may have to make a sudden move which can cause an accident. That is why it is always important to be aware of what is going on around you. -Hazardous Loads If you are transporting hazardous materials it is your responsibility to be aware of the special rules and regulations that YOU ARE REQUIRED TO FOLLOW. Consult with your safety director & DOT Handbook for these requirements. Learning Segment Introduction Driving Skills Tanker Driving Summary 17
Summary Here are some key points to keep in mind while transporting materials: Utilize the training and knowledge you have as a professional driver Incorporate the special driving techniques you have learned Treat the product with respect Its better to be in the defensive mode than to be unprepared Keep it slow. Keep it safe Driving Skills Always wear your seat belt. Keep a COOL head. Summary Ignore harassing gestures. Avoid eye contact. Understand that you can not control traffic, although you can control how you react to it. Remember, one angry act can ruin your life. 18