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Unit 1124 Title Describe Configurations, Weight, and Dimensions Document type Learning Resource

In consultation with industry subject matter experts, the BC Safety Council (BCFSC) facilitated the production of this material. Printed copies are considered uncontrolled and may be outdated. Current versions are available from the BCFSC. Feedback is welcome and may be sent to [email protected].

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Table of Contents Unit Introduction ...... 4 What you will learn in this unit ...... 4 Why it’s important for you to learn this unit ...... 4 Are you ready to take this unit? ...... 4 Does this unit apply to you? ...... 4 Section 1124 - 01: Configurations ...... 5 Key Point 1.1: and Trailer Configurations ...... 6 Truck Configurations...... 6 Single axle ...... 6 Tandem drive axles ...... 6 Tridem drive axles ...... 6 Setback Steering Axles ...... 6 Trailer Configurations ...... 6 Log Trailer Combinations ...... 7 Truck Configurations...... 8 Key Point 1.2: Influence of Configuration and Load on Handling and Stability . 10 Tracking and Effect of Hitch Mechanism ...... 10 Effect of Wheelbase on Tracking and Stability ...... 11 Stability of Fifth Wheel vs. Pintle Hitch ...... 11 Effect of Load Height ...... 12 Influence of axle spacing and width ...... 12 Driving steps to maintain stability, centre of gravity ...... 12 Effect of Loads when Turning Corner ...... 12 Effects of Lockers (Differential and Axle) Engaged in Relation to Turning ... 13 Section 1124 - 02: Weight and Dimensions...... 14 Key Point 2.1: Weights in Relation to Trucking ...... 15 Gross Vehicle Weight (GVW) ...... 15 Tare Weight ...... 15 Net Weight ...... 15 Allowable Weights ...... 16 Load Weights for Log Hauling ...... 16 Permits ...... 17 Key Point 2.2: Dimensions in Relation to Trucking ...... 18 Maximum Allowable Heights Loaded ...... 18 Allowable Length by Configuration ...... 18 Allowable Width as per Configurations ...... 19 Maximum Height of an Empty Log Truck ...... 19 Self-Quiz...... 20 Self-Quiz Answers...... 22

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Unit Introduction What you will learn in this unit By the end of this unit, you will be able to demonstrate knowledge of: • Truck configurations • Weight and dimensions Why it’s important for you to learn this unit Understanding truck configurations and the impact of weights and dimensions will help keep you safe on the road and assist you in operating within legal requirements. Are you ready to take this unit? To take this unit, you need to have completed one of the following units: • 1001 – Introduction to Online Learning (optional) • 1121 – Describe Trucking Industry Does this unit apply to you? This unit applies to the following occupations: • Log Truck Driver • Low Bed Truck Driver • Fuel Truck Driver • Truck-mounted Crane Truck Operator

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Section 1124 - 01: Configurations What you need to know about this section By the end of this section, you will be able to demonstrate knowledge of the following key points: 1.1 Truck and trailers configurations 1.2 Influence of configuration and load on handling and stability

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Key Point 1.1: Truck and Trailer Configurations Truck and trailer combination and their axle configurations (or group of axles) must be able to haul specific maximum weights within the legal height, width, and length specifications set out by provincial and federal authorities. Truck Configurations Truck configurations in British Columbia have three main types of axle groupings: • single • tandem • tridem More axles provide greater traction and weight carrying capacity. Single axle A single axle truck has only one drive axle in the rear. This type of truck is commonly used in light-duty service. Tandem drive axles A tandem axle truck has a pair of axles at the rear of the tractor. This configuration can provide greater traction and weight carrying capacity than a single axle. Tridem drive axles Tridem drive axle have a group of three axles at the rear of the tractor. Setback Steering Axles Trucks will have a forward set steering axle or a setback steering axle. A setback steering axle allows for a tighter turning radius, making the truck more maneuverable. It also allows for more weight to be distributed to the steering axle. Forward steer axles have been the standard for many years. Truck designs have incorporated the ability to have a setback steering axle if required. Trailer Configurations Like truck configurations, trailer configurations have the same three main types of axle groupings: lng_1124_Describe_Configurations_Weight_and_Dimensions.docx Page 6 of 22 Date October 1, 2019

• single axle • tandem axle • tridem axle Each group of axles has a different maximum weight carrying capacity. Trailer designs incorporate these combinations to meet safety regulations and weight and dimension regulations, while allowing for maximum payloads. Video 10:33 Watch: B.C. Logging Trucks #01 -- , , Western Star, White https://www.youtube.com/watch?v=Ti0tZ9e2cR8

Log Trailer Combinations The next two figures show log trailer combinations using a tridem axle pole trailer and a tandem axle pole trailer.

Figure 1: Tridem axle pole trailer

Figure 2: Tandem axle pole trailer

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Video 6:36 Watch: Logging Trucks #05 - Configurations https://www.youtube.com/watch?v=bXxMiKs-hX0

Logging Truck Configurations The following shows common logging truck configurations.

Figure 3: Common Configurations

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Remember! Allowable weights by configuration are provided by Commercial Vehicle Safety & Enforcement (CVSE).

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Key Point 1.2: Influence of Configuration and Load on Handling and Stability The truck and trailer configuration and the number of axles will determine weight and composition (including log length and number of trailers) of the load. This in turn impacts tracking, center of gravity, and maneuverability. Therefore, the configuration has a significant impact on handling and stability. Tracking and Effect of Hitch Mechanism Tracking is the deviation of the rear of the trailer from the tractor when navigating curves. It means how closely the rear of the trailer is going to follow the tractor when navigating curves. Tracking or off-tracking is influenced by the hitch point between the tractor and the trailer. The further forward the hitch point on the tractor, the greater the off-tracking will be. The distance between the front hitch point and the first set of axles also has an influence on tracking. Video 1:18 YouTube – Left Turn Off-Tracking https://www.youtube.com/watch?v=vOyk-tugW3k

The following figure shows the hitch path history and off-tracking of the trailer.

Figure 4: Off-tracking

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Effect of Wheelbase on Tracking and Stability Wheelbase has an effect on both tracking and stability. The longer the wheelbase of a tractor or trailer configuration is overall, the less maneuverable the unit will be. A longer wheel base can provide a smoother ride, but the loss of maneuverability and greater off-tracking can affect stability in tight situations. Stability of Fifth Wheel vs. Pintle Hitch Both fifth wheel and pintle hitch have advantages and disadvantages. A fifth-wheel hitch assembly has greater towing stability than a pintle hitch.

Figure 5: Fifth-wheel hitch

A pintle hitch provides greater articulation in situations that would bind other hitches.

Figure 6: Pintle hitch

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Effect of Load Height The higher the load of the unit is, the higher the centre of gravity will be which could result in an increased loss of stability. Influence of axle spacing and width The distance between the tires on the same axle measured from the outside of each tire is known as the “track”. Axles come in different widths. The most common widths are 8 feet and 8 feet 6 inches. A wider axle width provides greater stability. Knowing the measurements of your axles will help you understand the capabilities of your trucks handling. Driving steps to maintain stability, centre of gravity As a driver, you need to understand how load and stability affect how a truck handles. You must have the skills to drive appropriately in relation to the numerous forces at work such as speed, load size, and changing road conditions. You need to be alert, aware, and responsive. Reference BC Forest Safety Read Safety Alert: Preventing Log Truck Rollovers https://www.bcforestsafe.org/node/2807

Effect of Loads when Turning Corner The following are the three common types of suspension that each has an effect when cornering: • spring suspension • airbag suspension • walking beam suspension Cornering too quickly results in many accidents. Taking a corner too fast causes the load and truck weight to shift rapidly, which can cause a rollover. Rollovers are preventable. Driving with care and knowing your truck and load can help you avoid this needless danger. Your truck’s suspension has an impact on your truck’s cornering ability. Rigid suspensions lean less around corners and the truck has less sway. Spring and air bag suspensions have a smoother ride over a walking beam suspension but have more give when cornering. Driving with the limitations of your truck in mind can help to maintain road safely. While rigid suspensions inspire confidence while cornering by limiting lean, they can also prevent a driver from “feeling” potential catastrophe. Rigid suspensions can often maintain the feeling of lng_1124_Describe_Configurations_Weight_and_Dimensions.docx Page 12 of 22 Date October 1, 2019

stability right up to the point of rolling over, while air ride suspensions will often provide more feedback to the driver earlier as the unit leans when cornering. Effects of Lockers (Differential and Axle) Engaged in Relation to Turning The purpose of your truck’s power divider is to deliver more power to the wheels that have grip, and less to the ones that are slipping or spinning. Axle lockers lock the axles so that power is supplied to both wheels evenly. Having all your axles locked will give better traction but will make cornering more difficult as it will tend to push your truck straight, not allowing you to steer around a corner, especially in slippery conditions. Take care when using power dividers and axle lockers. You must understand how they work and how using any of these systems at the wrong time will cause mechanical damage or an incident. Remember! When your wheels are spinning, there is no time to read the manual.

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Section 1124 - 02: Weight and Dimensions What you need to know about this section By the end of this section, you will be able to demonstrate knowledge of the following key points: 2.1 Weights in relation to trucking 2.2 Dimensions in relation to trucking

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Key Point 2.1: Weights in Relation to Trucking The load capacity of your truck is determined by weight, not by available cargo space. It is important to understand some of the different terms used that describe how much load your vehicle is designed to carry or tow. These terms include the following: • Gross vehicle weight (GVW) • Tare weight • Net weight Gross Vehicle Weight (GVW) The GVW of the vehicle means the licensed maximum weight as per the vehicles certificate of registration. Tare Weight Tare weight is sometimes called the “unladen weight of the vehicle”. It is the weight of your empty truck. This includes all of its fluid, such as oil, coolants, and a minimal amount of fuel. Net Weight The net weight refers to the weight of your cargo alone. For example, if your six-axle log truck crosses the scales at 49,000 kilograms when loaded, and it weighs 15,500 kilograms when you cross the scales after your truck was unloaded; your net weight would be 33,500 kilograms (49,000 kg minus 15,500 kg equals 33,500 kg).

Remember! Gross weight – Tare weight = Net weight

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Figure 7: Example of the front of a weigh slip Allowable Weights The following table shows what the CVSE dictates as the weight that different configurations can haul.

Configuration Maximum weight Four-wheel single axle 9,100 kilograms Eight-wheel tandem axle 17,000 kilograms Twelve-wheel tri-drive axles 23,000 kilograms Twelve-wheel tridem trailer 24,000 kilograms Single steer axle 6,000 kilograms Single steer axle with a self-loader 9,100 kilograms Table 1: Configurations with weights Load Weights for Log Hauling In BC, the Ministry of Transportation and Infrastructure creates the regulations that identify the maximum limits allowed for the weight, height, width and length of loads. The Commercial Vehicle Safety and Enforcement (CVSE) is the organization that enforces these requirements at highway scale sites and through roadside inspections. Forest companies will also have specific requirements to follow such as overload policies and penalties. lng_1124_Describe_Configurations_Weight_and_Dimensions.docx Page 16 of 22 Date October 1, 2019

Permits Permits are required when outside the scope of conforming: • poles • highway crossing • height (over 4.15 m) (empty log truck 4.3 m) • length (over 23 m) • width (over 2.6 m) • weight (over legal axle weights)

CAUTION! A person must not, without a permit, drive or operate on a highway a logging truck if the gross vehicle weight of the truck exceeds 63, 500 kg.

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Key Point 2.2: Dimensions in Relation to Trucking Division 7 of the Commercial Transport Regulations describes the sizes and weights of commercial transport trucks operating on highways, including log trucks. The scope of the regulation includes the following: • vehicle width • trailer axle track widths • vehicle length and logging truck length • axles and axle configurations • gross weight Maximum Allowable Heights Loaded The overall maximum allowable height for a logging truck is 4.15 metres.

Figure 8: Heights Allowable Length by Configuration The Commercial Transport Regulations describe logging truck length as follows: • a logging truck two-vehicle combination that has a single articulation point and is carrying a load of logs, poles or wood pilings may have an overall length, including its load, of up to 21.5 m, but only if the length of the load cannot be reduced without cutting the wood • a logging truck combination that has more than one articulation point may have an overall length (OAL), including its load, of up to 23.0 metres OAL means the overall length measured from the front of the vehicle and/or load to the end of the vehicle and/or load.

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Remember! Any part of a load that extends more than 4 feet past the rear of the trailer must have a long load flag on it or a red light during dark hours.

Allowable Width as per Configurations The Commercial Transport Regulations describe vehicle width as follows: A vehicle cannot have a total outside width in excess of 2.6 m, not including the following as part of that width: • one or more mirrors, fitted for the purpose of conforming to the requirements of the Motor Vehicle Act Regulations, which do not extend more than 30 cm on each side beyond the total width of vehicle and load • auxiliary equipment or devices that are not designed or used to carry cargo and do not extend more than 10 cm on each side beyond the total width of vehicle and load, e.g., anti- splash and spray devices, load securement devices, , glad hands, air connectors, electrical connectors, hydraulic connectors, clearance lamps and dangerous goods placards • 445-mm-wide tires, fitted to the steering axles of a truck or truck tractor manufactured before January 1, 2005, that extend up to a maximum of 10 cm on either side of the vehicle beyond the maximum vehicle width of 2.6 metres Overall width means the overall width measured from the widest point on the left side of the vehicle and/or load to the other widest point on the right side of the vehicle. Maximum Height of an Empty Log Truck The maximum legal height of an empty log truck with trailer loaded on the back of the truck is 4.3 metres. This is more overall height than allowed for a truck loaded with logs due to an inability of industry to achieve the lower height for the reach/hitch assembly when the trailer is loaded onto the back of the truck.

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Self-Quiz

1. Which type of axle allows for a tighter turning radius? (1124.1.1)  Tandem axle  Tridem axle  Forward steer axle  Set back steering axle

2. What is the effect of a longer wheelbase? (1124.1.2)

 Bumpier ride  Less off tracking  More maneuverability  Less maneuverability

3. What happens to the amount of off track in a longer wheel base unit? (1124.1.2)  Increases  Decreases  Decreases then increases  Increases then decreases

4. What is the amount of allowable weight tolerance in the winter? (1124.2.1)  1,000 kg.  1,500 kg.  2,000 kg.  2,500 kg.

5. How do you calculate for the net weight? (1124.2.1)  Tare weight minus axle weight  Axle weight plus tare weight  Gross weight minus tare weight  Gross weight minus axle weight lng_1124_Describe_Configurations_Weight_and_Dimensions.docx Page 20 of 22 Date October 1, 2019

6. What is the maximum legal width of a vehicle that will be operated on a highway without a permit? (1124.2.2)  2 metres  2.6 metres  2.9 metres  3.2 metres

7. What is the maximum legal height of an empty log truck with trailer loaded on the back of the truck? (1124.2.2)  3.2 metres  4.1 metres  4.3 metres  4.7 metres

8. What is included when calculating load dimension? (1124.2.2)  Width, length, height  Length, weight, height  Length and weight  Width and height

Now check your answers on the next page.

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Self-Quiz Answers

1. Which type of axle allows for a tighter turning radius? Answer: Set back steering axle

2. What is the effect of a longer wheelbase? Answer: Less maneuverability

3. What happens to the amount of off track in a longer wheel base unit? Answer: Increases

4. What is the amount of allowable weight tolerance in the winter? Answer: 2,500 kg.

5. How do you calculate for the net weight? Answer: Gross weight minus tare weight

6. What is the maximum legal width of a vehicle that will be operated on a highway without a permit? Answer: 2.6 metres

7. What is the maximum legal height of an empty log truck with trailer loaded on the back of the truck? Answer: 4.3 metres

8. What is included when calculating load dimension? Answer: Width, length, height

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