Load, Haul, and Transport Support

Load, Transport, and Material Handling Support

Module Introduction

This chapter covers load, transport, and material handling support operations for the bulldozer operator. In the context of the Red Seal exam, these tasks are not limited to pushing dirt: they encompass coordination with loading equipment (loaders, excavators), transporting materials on haul roads, handling suspended loads, and managing production cycles. You must understand the physical principles, safety procedures, production calculations, and applicable Canadian standards.

This module represents approximately 15 to 20% of the exam questions for the bulldozer trade. Questions focus on safety, stability, communication signals, volume calculations, and equipment coordination.

Fundamental Principles of Loading and Transport

The Bulldozer Production Cycle

The bulldozer is a traction and pushing machine. In a load-transport cycle, it performs three distinct roles:

8.Pushing materials toward a loader or crusher (feeding).

9.Grading and maintaining haul roads for haul trucks.

10.Towing or pushing equipment (compactors, rollers, etc.).

The complete cycle includes: approach, blade penetration, loading, hauling, dumping, and return. Each phase must be optimized to minimize downtime.

Theoretical vs. Actual Production

The theoretical production of a bulldozer is calculated in cubic meters per hour (m³/h) :

Theoretical Production = (Volume per cycle × Number of cycles per hour)

The number of cycles per hour = 3600 seconds ÷ total cycle duration in seconds.

Example: If a bulldozer moves 4.5 m³ per cycle and the cycle takes 45 seconds:

Cycles/hour = 3600 ÷ 45 = 80 cycles

Theoretical production = 4.5 × 80 = 360 m³/h

Actual production incorporates an efficiency factor (typically 0.75 to 0.85 depending on conditions) and a blade fill factor (0.80 to 1.10 depending on material).

Actual Production = Theoretical Production × Efficiency Factor × Fill Factor

Factors Affecting Production

Factor	Impact on Production	Typical Range
Material type	Density, cohesion, abrasiveness	0.60 to 1.10 (fill factor)
Haul distance	Increases cycle time	15 to 60 m optimal for bulldozer
Grade (uphill/downhill)	Reduces speed uphill	±10% per 1% grade
Road condition	Rolling resistance	0.05 to 0.15 (coefficient)
Operator skill	Loading technique	±15%
Equipment maintenance	Undercarriage wear	±10%

Calculating Motion Resistance

The force required to move a loaded bulldozer is calculated as follows:

Total Force (N) = Rolling Resistance + Grade Resistance + Acceleration Resistance

Rolling Resistance = Total weight (kg) × Rolling coefficient × 9.81

Grade Resistance = Total weight (kg) × 9.81 × Sin(grade angle)

For a grade expressed as a percentage, use: Grade Resistance = Total weight × 9.81 × (% grade ÷ 100)

Example: A bulldozer weighing 30,000 kg (total weight with load) on a road with a rolling coefficient of 0.08 and a 5% grade:

Rolling resistance = 30,000 × 0.08 × 9.81 = 23,544 N

Grade resistance = 30,000 × 9.81 × 0.05 = 14,715 N

Total force = 23,544 + 14,715 = 38,259 N (approximately 38 kN)

Coordination with Loading Equipment

Bulldozer Positioning

When the bulldozer feeds a loader or crusher, positioning is critical:

Approach angle: 30° to 45° relative to the receiving hopper.

Safety distance: minimum 3 m between the blade and the loading equipment.

Escape zone: always plan a clear retreat path.

Communication Signals

Hand and voice signals are standardized according to the Canada Occupational Health and Safety Regulations (COHSR) and industry standards. Essential signals for the bulldozer:

Signal	Meaning	Required Action
Closed fist raised	Stop	Stop immediately
Arm horizontal, palm facing down	Slow down	Reduce speed
Index finger pointing up	Raise blade	Raise the blade
Index finger pointing down	Lower blade	Lower the blade
Circular hand motion	Move forward	Move forward
Hand pushing motion	Move backward	Move backward

Golden rule: If the signal is ambiguous or absent, stop the equipment. Never guess.

Radio Communication

Radio communication must use clear, standardized terminology. Each piece of equipment has a unique call sign. Messages must be short, precise, and confirmed by the receiver.

Standard protocol:

46.Call: "Base to Dozer 3, do you copy?"

47.Response: "Dozer 3 to base, I read you loud and clear."

48.Message: "Dozer 3, loader 1 is down, proceed to area B."

49.Confirmation: "Copy, proceeding to area B."

Load Handling and Stability

Bulldozer Stability Principles

The bulldozer is designed to push, not to lift. Stability depends on three factors:

53.Centre of gravity: the lower it is, the more stable the machine.

54.Support base: the distance between track contact points.

55.Overturning moment: the product of weight times the horizontal distance to the tipping point.

Overturning moment = Weight × Horizontal distance

The bulldozer tips when the overturning moment exceeds the stabilizing moment (machine weight × distance to the opposite tipping point).

Safety Rules for Load Handling

Never lift a load with the blade beyond the safe height (generally 30 cm above the ground for transport).

On a slope, always orient the blade toward the slope (uphill or downhill) to maximize stability.

Never turn the bulldozer with a raised load on a side slope.

Suspended loads (slings, chains) must be inspected before each use according to CSA Z150 (Safety Code on Mobile Cranes) and CSA B167 (Safety Standard for Overhead Cranes).

Calculating Lifting Capacity

The bulldozer is not a lifting machine. Its lifting capacity is limited by blade geometry and hydraulic pressure. The approximate formula:

Lifting capacity (kg) = (Hydraulic pressure (Pa) × Cylinder area (m²)) ÷ 9.81

Example: A blade cylinder with a pressure of 20 MPa (20 × 10⁶ Pa) and a piston area of 0.02 m²:

Force = 20 × 10⁶ × 0.02 = 400,000 N

Capacity = 400,000 ÷ 9.81 = 40,775 kg (theoretical, never achieved in practice)

In practice, lifting capacity is limited to approximately 10-15% of the machine's weight to prevent tipping.

Haul Road Maintenance

The Bulldozer's Role in Road Maintenance

The bulldozer is the primary equipment for haul road maintenance. A well-maintained road:

Reduces truck rolling resistance (fuel savings).

Extends tire and suspension service life.

Improves safety (less risk of rollover).

Increases truck travel speed.

Ideal Road Profile

Parameter	Recommended Value	Reason
Road width	3 to 4 times the width of the largest truck	Allow passing
Cross slope	2 to 3% toward the outside	Water drainage
Longitudinal grade	Maximum 8% uphill	Limit speed loss
Curve radius	Minimum 15 m	Truck stability
Wearing course thickness	15 to 30 cm of compacted material	Strength and drainage

Maintenance Procedure

80.Visual inspection: identify potholes, ruts, and drainage areas.

81.Grading: use the blade in grading position (30° to 45° angle) to level the surface.

82.Compaction: run the roller or use the bulldozer's weight with the blade slightly raised.

83.Drainage check: ensure water flows toward the side ditches.

Canadian Standards and Regulations

Canadian Electrical Code, Part I, Chapter V

Although the bulldozer is not directly connected to the electrical grid, it may work near power lines. The Canadian Electrical Code, Part I, Chapter V (C22.1-21) defines minimum clearance distances.

Rule 5-200: Minimum distances between construction equipment and power lines:

Line Voltage	Minimum Distance
0 to 750 V	3 m
750 V to 75 kV	4.5 m
75 kV to 300 kV	6 m
Over 300 kV	10 m

Rule 5-204: If the minimum distance cannot be maintained, the operator must obtain written authorization from the line owner and implement protective measures (barriers, signalers).

CSA B149.1 — Natural Gas and Propane Code

The bulldozer may work near gas pipelines. CSA B149.1 (Natural Gas and Propane Installation Code) defines safety rules:

Clause 4.10.2: No motorized equipment shall travel over a gas pipeline without appropriate protection.

Clause 4.10.3: Excavation work within 3 m of a pipeline must be done manually or with approved equipment.

Clause 4.10.5: If a pipeline is damaged, the operator must immediately stop the equipment, evacuate the area, and call emergency services.

Canada Occupational Health and Safety Regulations (COHSR)

The COHSR (SOR/86-304) applies to worksites under federal jurisdiction. Relevant sections:

Section 14.5: Mobile vehicles and equipment must be equipped with an audible warning device.

Section 14.6: Communication signals must be understood by all workers.

Section 14.8: Operators must be trained and competent for the equipment they use.

Section 14.11: Vehicle traffic areas must be separated from pedestrian areas.

CSA Z150 — Safety Code on Mobile Cranes

Although the bulldozer is not a crane, this standard applies when the bulldozer is used to lift loads with attachments (buckets, grapples). The standard requires:

Daily inspection of lifting attachments.

Calculation of the maximum allowable load.

Adequate signaling for lifting operations.

Specific Operational Procedures

Loading Materials into a Truck

The bulldozer can load a truck by pushing material directly into the box. Procedure:

109.Position the truck perpendicular to the pushing direction.

110.Ensure the truck is stationary with the parking brake engaged.

111.Approach with the blade 15-20 cm above the ground.

112.Push the material until it falls into the box.

113.Reverse and repeat until the box is full (do not exceed the box level).

Safety rule: Never push material over the truck cab. Always push toward the box, never toward the cab.

Feeding a Crusher

Feeding a crusher is a critical operation:

Maintain a constant feed rate to avoid blockages.

Never push materials larger than the crusher opening.

Maintain a 5 m safety distance around the hopper.

Use a signaler if visibility is reduced.

Towing Equipment

The bulldozer can tow other equipment (compactors, rollers):

Use a certified tow cable or chain (minimum safety factor of 5).

The towing load must not exceed the bulldozer's drawbar capacity.

Towing speed must not exceed 5 km/h.

A signaler must be present if visibility is reduced.

Volume and Tonnage Calculations

Volume-Density Conversion

To convert volume to tonnage:

Mass (t) = Volume (m³) × Density (t/m³)

Material	Density (t/m³)	Swell Factor
Topsoil	1.2 to 1.5	1.25
Clay	1.6 to 1.8	1.30
Dry sand	1.5 to 1.7	1.10
Gravel	1.7 to 1.9	1.15
Crushed rock	1.6 to 1.8	1.35
Compacted earth	1.8 to 2.0	1.00

Swell factor: the ratio between in-bank volume and loose volume (after excavation). A factor of 1.25 means that 1 m³ of in-bank earth becomes 1.25 m³ once excavated.

Calculating Truck Load

Load (t) = Box volume (m³) × Material density (t/m³) × Fill factor

Example: A truck with a 20 m³ box loaded with gravel (density 1.8 t/m³) with a fill factor of 0.95:

Load = 20 × 1.8 × 0.95 = 34.2 tonnes

Calculating the Number of Haul Cycles

Number of trucks required = (Truck cycle time) ÷ (Truck loading time)

Example: A truck has a 12-minute cycle (loading + hauling + dumping + return). Loading time is 3 minutes:

Number of trucks = 12 ÷ 3 = 4 trucks

If you have fewer trucks, the bulldozer waits; if you have more, the trucks wait.

Slope and Ramp Management

Operations on Slopes

The bulldozer is designed to work on slopes, but with limits:

Slope	Permitted Operation	Precautions
0 to 10%	All operations	None
10 to 20%	Pushing downhill	Reduce speed, blade low
20 to 30%	Pushing uphill	Use counterweight, reduced speed
Over 30%	Prohibited	Use a winch or other equipment

Slope Work Technique

147.Uphill: keep the blade 10-15 cm above the ground to serve as an emergency brake.

148.Downhill: use the blade as a brake by letting it drag slightly on the ground.

149.Traversing slopes: always work perpendicular to the slope, never diagonally.

150.Changing direction: make turns on flat ground or at the bottom of the slope.

Pitfalls to Avoid

152.Confusing theoretical and actual production: forgetting the efficiency and fill factors is the most common error. Always apply both factors.

153.Neglecting the swell factor: material volumes are often given in-bank, but equipment works with loose volume. Conversion is mandatory.

154.Ignoring electrical clearance distances: the Canadian Electrical Code distances are absolute minimums. Never round them down.

155.Overloading the blade: blade capacity is a limit, not a target. Overloading reduces stability and increases cycle time.

156.Working on slopes without assessment: always assess the slope before starting. A seemingly gentle slope can become dangerous with a load.

157.Forgetting communication signals: an misunderstood signal is a hazard. Always confirm before acting.

158.Using the bulldozer as a crane: the bulldozer is not designed for lifting suspended loads. Heavy loads must be lifted with a certified crane.

159.Neglecting road maintenance: a poorly maintained road increases fuel consumption by 20 to 30% and increases accident risk.

160.Confusing provincial and federal standards: the Red Seal exam covers national standards (CSA, Canadian Electrical Code, COHSR). Provincial standards are not assessed.

161.Not checking ground conditions: water-saturated soil reduces bearing capacity and increases the risk of getting stuck. Always assess bearing capacity before proceeding.

Summary

The bulldozer production cycle includes approach, penetration, loading, hauling, dumping, and return.

Actual production = theoretical production × efficiency factor × fill factor.

Total travel force = rolling resistance + grade resistance + acceleration resistance.

Communication signals must be standardized and confirmed.

The bulldozer is not a lifting machine; its lifting capacity is limited by stability.

Road maintenance is an essential bulldozer function: profile, drainage, compaction.

The Canadian Electrical Code, Part I, Chapter V (Rule 5-200) sets minimum electrical clearance distances.

CSA B149.1 governs work near gas pipelines.

The COHSR (SOR/86-304) applies to federal worksites.

Volume calculations must incorporate the swell factor and material density.

Slope operations are limited to a maximum of 30%, with specific precautions.

Final Exam Tips

Memorize the formulas: production, force, volume, load. They appear consistently.

Learn the tables: densities, swell factors, electrical distances, slope limits.

Re-read the questions: examiners like conversion traps (m³ to tonnes, hours to seconds).

Visualize the situations: for safety questions, picture the scene and identify the primary hazard.

Manage your time: calculation questions take longer. Answer the quick questions first, then return to the calculations.

Good luck with your Red Seal exam preparation.