6.7. Hostile Terrain & Resistance Factors

• Gather the recovery team and conduct a safety briefing to ensure everyone understands their roles and responsibilities.
• Establish clear communication protocols and signals.

• Evaluate the terrain’s stability and ground conditions.
• Consider factors such as soil type, slope, weather conditions (rain can make terrain unstable), and any signs of instability (cracks, loose rocks, etc.).
• Determine if the ground can support the weight of the recovery vehicle and the casualty.

• Identify obstacles in the recovery path such as rocks, trees, or other terrain features that may impede progress.
• Assess the size, shape, and stability of these obstacles.
• Plan for their avoidance or removal, if necessary, using appropriate tools and equipment.

• Determine the best route to reach the casualty, considering ground stability and obstacles.
• Prioritize safety by avoiding steep inclines, unstable terrain, or areas prone to avalanches or landslides.
• Mark the extrication path clearly, using markers or guides if possible.

• Assess the need for anchors to secure the recovery vehicle and prevent it from sliding or tipping over during the operation.
• Identify natural anchors like sturdy trees or rocks, or consider using artificial anchors like winch points or ground anchors.
• Ensure that anchors are placed at safe distances and angles to provide effective support.

• Ensure that all recovery equipment, such as winches, cables, straps, and hooks, are in good working condition.
• Verify that all safety gear, including helmets, harnesses, and gloves, is available and properly maintained.
• Prepare any specialized equipment needed for the specific terrain and casualty.

• Conduct a thorough risk assessment to identify potential hazards and risks associated with the recovery operation.
• Develop a risk mitigation plan that includes contingency measures and escape routes in case of unexpected situations.

• Assess the condition of the casualty to determine the appropriate method of extraction and any medical requirements.
• Coordinate with medical personnel if necessary and ensure that the casualty is stabilized before attempting recovery.

• Begin the recovery operation, following the planned extrication path and using anchors and equipment as required.
• Continuously monitor ground stability, obstacles, and the condition of the recovery vehicle and casualty during the operation.
• Maintain clear communication among team members and be prepared to adapt the plan if conditions change.

• After the recovery is complete, conduct a debriefing session to discuss what went well and any lessons learned.
• Document any equipment damage or issues for future maintenance.
• Review the operation and consider improvements for future operations.

The type of terrain on which the towing or recovery operation takes place can significantly impact the resistance. Rough and uneven terrains, such as off-road trails or mountainous areas, can create additional resistance compared to smooth, paved roads

Adverse weather conditions, such as rain, snow, ice, or mud, can increase resistance. Slippery surfaces can make it challenging to tow or recover a vehicle safely.

Obstacles like trees, rocks, or debris on the road can increase resistance and pose hazards during the towing or recovery process.

Crossing bodies of water adds resistance, and the depth and current of the water can significantly affect the operation’s success.

When towing or recovering vehicles on busy roads, traffic congestion can create resistance, slowing down the operation and increasing the risk of accidents.

Heavier vehicles create more resistance and require more powerful towing equipment. Towing a heavy vehicle may necessitate a specialized towing truck with higher capacity.

The condition of the disabled vehicle affects the resistance. A vehicle with extensive damage may be more challenging to tow or recover due to misaligned wheels, locked brakes, or structural damage.

Flat tires or damaged wheels can increase resistance when towing or recovering a vehicle. Properly inflated and functional tires reduce resistance.

The type of vehicle being towed or recovered matters. Different types, such as motorcycles, cars, trucks, or large commercial vehicles, may require specialized equipment and techniques.

The weight of the vehicle you plan to tow is a critical factor in calculating rolling resistance. You’ll need to know the total weight of the disabled vehicle, including any passengers or cargo if applicable. This weight is typically measured in pounds or kilograms.

Rolling resistance also depends on the condition of the tires on both the towing vehicle and the disabled vehicle. Tire condition is represented by the coefficient of rolling resistance (Crr). This coefficient is a dimensionless number typically provided by tire manufacturers for specific tire types and conditions. It can vary depending on the tire’s design, tread pattern, inflation pressure, and wear. Look for the Crr value in the tire’s specifications or consult the manufacturer.

The type of road or surface on which you plan to tow the vehicle can significantly affect rolling resistance. Different road surfaces, such as asphalt, concrete, gravel, or off-road terrain, will have varying coefficients for rolling resistance. This value is usually determined empirically or found in engineering references.

Consider any additional environmental factors that may affect rolling resistance. For example, strong headwinds or towing uphill will increase resistance, while tailwinds or towing downhill may reduce resistance. These factors are often challenging to quantify precisely but should be considered in your overall assessment.

To calculate rolling resistance, you can use the following formula:

Hard Surface Reistance = .05

(concrete, hard grass, gravel)

Soft Surface Resistance = .15

(soft grass or gravel)

Keep in mind that rolling resistance is just one of the forces you need to overcome during towing. You may also need to account for other forces, such as air resistance, grade resistance (if towing on an incline), and any additional forces due to vehicle damage or obstacles.

Based on the calculated rolling resistance force, choose towing equipment, such as a tow truck or trailer, with sufficient capacity to overcome this force. Make sure to consider safety margins to handle unexpected variations in resistance.