Sliding tandems on a reefer trailer is a crucial skill for maintaining legal weight distribution and ensuring safe and efficient transportation of temperature-sensitive goods. Understanding the mechanics, safety precautions, and regulatory requirements involved is paramount for every professional truck driver.
The Importance of Sliding Tandems
Sliding the tandems, or trailer axles, allows drivers to redistribute the weight across the axles, ensuring compliance with federal and state weight regulations. This is especially important for reefer trailers, which often carry heavy loads of produce, meat, or other perishable items. Incorrect weight distribution can lead to:
- Overweight axle fines: These can be substantial and impact a driver’s record.
- Vehicle instability: Improper weight distribution can make the trailer difficult to handle, especially during braking or cornering.
- Damage to roads and infrastructure: Exceeding weight limits can cause damage to bridges and highways.
Sliding tandems also plays a role in optimizing bridge law compliance. This law dictates maximum weight allowed on specific axle groupings to protect bridges and infrastructure.
Step-by-Step Guide to Sliding Tandems
Sliding tandems requires a systematic approach and careful attention to detail. Here’s a detailed guide:
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Assess the Situation: Before you even think about moving the tandems, determine why you need to slide them. Are you too heavy on the drive axles? Are you too heavy on the trailer axles? Is your overall gross weight exceeding the legal limit? Knowing the “why” will help you decide which way to slide, and how far. Use a CAT Scale or similar certified scale to accurately determine your weight distribution.
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Safety First: Park the trailer on a level surface, engage the parking brake, and chock the wheels. Visibility is key. Make sure you are not obstructing traffic and that you have adequate lighting if performing this task at night.
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Release the Tandem Locks: Located on the trailer’s side, typically near the wheels, you’ll find the tandem lock pins. These pins secure the tandem axles in their current position. Release the pins by pulling the release handle (usually a T-handle or a lever). Some trailers have air-operated release mechanisms; if so, engage the system as per the manufacturer’s instructions. Often, you may need to “bump” the trailer forward or backward very slightly to relieve pressure and allow the pins to fully retract.
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Slightly Inflate Airbags (If Equipped): Some newer reefer trailers utilize air-ride suspension. Slightly inflating the airbags can make the sliding process smoother, particularly if the track is dirty or rusty. Consult your trailer’s manual for proper airbag inflation procedures.
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Slide the Tandems: Carefully and slowly move the tractor forward or backward while maintaining a straight line. This will move the tandem axles along the sliding rails. Observe the movement and ensure the axles are sliding evenly.
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Position the Tandems: Use the graduated markings on the trailer frame or sliding rail to accurately position the tandems. Refer to your scale ticket or weight distribution calculations to determine the optimal position.
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Engage the Tandem Locks: Once the tandems are in the desired position, release the release handle to engage the locking pins. Ensure all pins are fully engaged and locked. You may need to “bump” the trailer again to allow the pins to lock completely. Visually inspect each pin to confirm it is securely in place.
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Double-Check and Verify: After sliding the tandems, re-weigh the trailer at a certified scale to confirm that the weight distribution is within legal limits. This is the most critical step to avoid fines and ensure safety.
Frequently Asked Questions (FAQs)
FAQ 1: What tools do I need to slide tandems on a reefer trailer?
Generally, you only need basic tools: wheel chocks, gloves, and potentially a hammer to help dislodge stubborn locking pins. A flashlight is helpful for visibility in low-light conditions.
FAQ 2: How do I know how far to slide the tandems?
The best approach is to use a certified scale and analyze your weight distribution. Based on the scale readings, calculate the necessary adjustment to bring your axles within legal weight limits. Consider using a weight distribution calculator app on your smartphone for convenience. Remember, each notch on the sliding rail represents a specific weight shift, which can vary depending on the trailer’s design and load.
FAQ 3: What happens if the tandem pins are stuck?
First, ensure the parking brake is firmly engaged. Try rocking the trailer slightly forward and backward by gently accelerating and decelerating the tractor. This can help dislodge the pins. If that doesn’t work, use a hammer and a punch to gently tap the pins, taking care not to damage them. Penetrating oil can also help loosen rusted pins. If the pins remain stuck, consult a qualified mechanic.
FAQ 4: Can I slide tandems with a full load?
Yes, sliding tandems with a full load is common, but it’s crucial to ensure the trailer is on a level surface. Uneven ground can put excessive strain on the sliding mechanism. Also, sliding a fully loaded trailer requires more power from the tractor and a slower, more controlled sliding process.
FAQ 5: How often should I inspect the tandem sliding mechanism?
Regular inspections are crucial for safety and efficiency. Inspect the sliding rails, locking pins, and release mechanism before each trip. Look for signs of wear, damage, or corrosion. Lubricate the sliding rails and locking pins periodically to ensure smooth operation.
FAQ 6: What are the consequences of not sliding tandems properly?
Failing to slide tandems properly can result in overweight axle fines, vehicle instability, and damage to roads and bridges. It can also lead to out-of-service orders from law enforcement, delaying your delivery and impacting your driving record.
FAQ 7: How does the type of cargo affect the weight distribution?
The density and distribution of the cargo within the reefer trailer significantly impact weight distribution. Denser cargo concentrated at the front or rear of the trailer will create a heavier load on the respective axles. Unevenly distributed cargo can also create side-to-side imbalances, affecting handling and stability.
FAQ 8: Are there any specific regulations for sliding tandems on reefer trailers?
While there aren’t specific regulations solely for reefer trailers, all trucks must comply with federal and state weight regulations based on axle weight limits and bridge law formulas. These regulations apply to all trailers, including reefers. Regularly consult your state’s Department of Transportation (DOT) website for the most up-to-date regulations.
FAQ 9: What’s the difference between a sliding tandem and a spread axle trailer?
A sliding tandem allows you to adjust the axle position along a sliding rail, concentrating the weight within a smaller area. A spread axle trailer has axles spaced further apart, distributing the weight over a larger area. Spread axle trailers often offer higher weight limits but may be subject to specific restrictions in certain states.
FAQ 10: Can weather conditions affect the sliding process?
Yes. Extreme cold can cause the grease and lubricants to thicken, making the sliding process more difficult. Ice and snow can create slippery conditions, making it harder to maintain control while sliding the tandems. Ensure the area is clear of ice and snow before attempting to slide the tandems in winter.
FAQ 11: What is “bridge law” and how does it relate to sliding tandems?
Bridge law establishes maximum weight limits for specific axle groupings (e.g., the distance between the first and last axles) to prevent damage to bridges. Sliding tandems allows you to adjust the axle spacing to comply with these bridge law formulas. Failing to comply can result in significant fines.
FAQ 12: What are some common mistakes drivers make when sliding tandems?
Common mistakes include:
- Failing to properly engage the locking pins: This can lead to the tandems shifting unexpectedly during transit.
- Not re-weighing the trailer after sliding: This is critical to verify weight distribution and avoid fines.
- Sliding the tandems on uneven ground: This can damage the sliding mechanism.
- Ignoring the graduated markings: This can lead to inaccurate positioning and incorrect weight distribution.
- Forgetting to release the parking brake when sliding (or engaging it while moving): This can damage the braking system.
By following these guidelines and understanding the intricacies of sliding tandems, drivers can ensure safe, legal, and efficient transportation of temperature-sensitive goods. Always prioritize safety and consult relevant regulations to maintain compliance.