Flatbed Load Securement Basics - Straps vs Chains, Working Load Limit, and Edge Protection

One of the most critical responsibilities of a flatbed driver is ensuring that every load is properly secured. Unlike dry van loads enclosed within a trailer, freight on a flatbed is exposed to wind, weather, and road vibrations. Securement failures can cause cargo to shift, fall, or become projectiles—all of which endanger other motorists, damage the load, and result in hefty fines. The Federal Motor Carrier Safety Administration (FMCSA) enforces strict cargo securement rules, and understanding these guidelines is essential for your safety and legal compliance.

This guide explores the fundamentals of flatbed load securement, including when to choose straps versus chains, how to calculate the working load limit (WLL), minimum tie‑down requirements, and why edge protection matters. Whether you’re a rookie driver or a seasoned pro who needs a refresher, this article provides actionable advice and lists to help you keep your loads—and your career—on track.

Why Proper Securement Matters

Improperly secured loads cause thousands of accidents every year. When a strap breaks or a chain comes loose, cargo can slide off a trailer and onto the roadway, creating life‑threatening hazards. FMCSA’s cargo securement rules exist to prevent these incidents. Drivers are required to know how many tie‑downs are needed for each load and how to calculate whether those tie‑downs are strong enough. Failing to comply can result in citations, out‑of‑service orders, or even criminal charges if someone is hurt.

Proper securement also protects your reputation and your company’s bottom line. Damaged cargo can lead to insurance claims, lost business, and dissatisfied customers. Conversely, demonstrating that you understand securement fundamentals can earn you trust and better freight assignments.

Straps vs Chains: Choosing the Right Tie‑Down

A fundamental decision in flatbed securement is whether to use ratchet straps or steel chains. Each has its own advantages and ideal use cases:

Ratchet Straps

Ratchet straps are made from webbed polyester or nylon and are typically 2 to 4 inches wide. They are tightened using a ratcheting mechanism that can apply significant tension. Here’s when straps are ideal:

• Lighter or irregular loads: Straps conform to the shape of irregular items, such as palletized goods, lumber, or machinery with delicate surfaces. Their flexibility allows them to hug the load securely.
• Protecting surfaces: Nylon or polyester straps are less likely to scratch or dent cargo, making them a good choice for finished goods or painted equipment.
• Ease of use: Ratchet straps are lightweight and easy to handle. They can be quickly attached and tightened by one person.

However, straps have limitations. They can be cut by sharp edges or abraded by rough surfaces. They also have a lower working load limit than chains of comparable size. Never use a damaged strap; if you see cuts, fraying, or UV damage, replace it immediately.

Steel Chains

Steel chains are heavier and stronger than straps. They’re typically rated by Grade 70 (transport chain) or Grade 80/100 (higher strength). Chains are tightened using binders and are ideal for:

• Heavy equipment: Bulldozers, forklifts, and other heavy machinery require chains to handle their weight and keep them firmly anchored.
• Loads with sharp edges: Chains are less likely to be damaged by sharp corners or abrasive materials.
• Extreme conditions: Chains resist UV damage and are less affected by temperature extremes.

The downside is that chains can damage finished surfaces if not properly padded, and they’re heavier to handle. Drivers must be physically capable of lifting and tightening chains and must use proper binders to apply tension.

Understanding Working Load Limit (WLL)

The working load limit (WLL) represents the maximum force a tie‑down can safely withstand. FMCSA’s cargo securement rules require that the aggregate WLL of the tie‑down system be at least one half the weight of the cargo. In practice, this means you must calculate the total weight of the load and ensure your straps or chains can handle at least half of that weight. To do this:

1. Determine cargo weight: Verify the weight of your cargo by checking shipping documents or weighing the loaded truck at a scale.
2. Check individual WLL ratings: Each strap or chain is labeled with a WLL. For example, a 4‑inch polyester strap may have a WLL of 5,400 lbs, while a Grade 70 3/8‑inch chain might be rated at 6,600 lbs.
3. Sum the WLLs: Add the WLL of all tie‑downs that will resist movement in a given direction. If you’re securing a pallet of steel coils that weighs 10,000 lbs, the combined WLL of the tie‑downs must be at least 5,000 lbs.
4. Consider angles: Tie‑down angle affects strength. The greater the angle between the tie‑down and the deck, the more WLL is lost. A tie‑down angled at less than 30 degrees from the deck loses significant strength. Aim for 45 degrees or more for optimal effectiveness.

Minimum Tie‑Down Requirements

In addition to WLL calculations, FMCSA rules specify the minimum number of tie‑downs based on the cargo’s length and weight. These requirements are designed to ensure loads are secured even if one tie‑down fails:

• Loads 5 ft or less and weighing 1,100 lbs or less: At least one tie‑down is required.
• Loads 5 ft or less and weighing over 1,100 lbs, or loads greater than 5 ft but less than 10 ft: At least two tie‑downs are needed.
• Loads over 10 ft: A minimum of two tie‑downs must secure the first 10 ft of cargo, plus one additional tie‑down for each additional 10 ft or fraction thereof.

Remember that these are minimums. In practice, you may need more tie‑downs to achieve the necessary WLL or to prevent movement in all directions.

Edge Protection and Preventing Wear

One of the most overlooked aspects of securement is edge protection. Sharp edges or abrasive surfaces can cut straps or wear down chains. To protect both your tie‑downs and your cargo:

• Use corner protectors on sharp edges. These can be plastic or metal guards placed between the strap or chain and the cargo to distribute pressure and prevent cutting.
• Use rubber mats or dunnage under chains or straps to increase friction and prevent slippage.
• Inspect edges and surfaces: Before loading, walk around the cargo and identify any points that could damage your tie‑downs. Cover or pad these areas.
• Check tie‑downs during transit: After 50 miles, stop and re‑check your straps or chains for loosening. Vibration can cause them to slacken; tightening them prevents shifting.

Rechecking and Maintenance

Flatbed drivers must constantly monitor their loads. Here’s how to keep your securement system in top shape:

1. Initial re‑check: After driving roughly 50 miles, pull over to a safe area and re‑check all tie‑downs. Tighten straps or chains if they’ve loosened.
2. Periodic checks: FMCSA rules require rechecking when you have driven 3 hours or 150 miles, whichever comes first, and after each duty change. Get into the habit of checking during fuel stops or rest breaks.
3. Replace damaged equipment: Retire any straps with cuts, frayed edges, broken stitching, or UV damage. Replace chains that show cracked links, excessive rust, or bent hooks. Always carry spare straps and chains to avoid delays.
4. Lubricate binders and ratchets: Apply lubricant to binders and ratchets regularly so they operate smoothly and lock securely.

Building a Securement Routine

Successful drivers follow a consistent routine when planning and securing loads. Use the following steps to organize your process:

Pre‑Load Planning

• Know your cargo: Understand the weight, length, and number of pieces you’ll be securing.
• Determine WLL requirements: Calculate your total load weight and the WLL needed. Decide how many straps or chains will meet or exceed that requirement.
• Select equipment: Choose straps or chains based on cargo type—chains for heavy machinery, straps for palletized goods. Gather edge protection, ratchets, binders, and other accessories.
• Position tie‑downs before loading: Lay out straps or chains on the trailer deck at the points where they’ll be used. This saves time once the cargo is on board.

Securing the Load

• Load in delivery order: If delivering to multiple locations, place items you’ll drop off first at the rear or top of the load. This prevents unnecessary shuffling.
• Apply tie‑downs: Run straps or chains over the cargo and secure them to the trailer’s D‑rings or rub rails. Use binders or ratchets to remove slack and create downward pressure.
• Crisscross when appropriate: For tall or unstable loads, crisscross tie‑downs to resist movement forward, backward, and sideways.
• Check angles: Adjust the angle of your tie‑downs to maximize holding power—45 degrees or less is ideal.
• Edge protection: Install corner protectors or padding wherever straps or chains contact sharp edges.

Post‑Load Checks

• Walk‑around inspection: Once all tie‑downs are in place, walk around the trailer. Look for uneven tension, twisted straps, loose chains, or missing corner protectors. Adjust as necessary.
• Confirm WLL: Double‑check that the total WLL of your tie‑downs meets or exceeds half the cargo weight. If not, add more tie‑downs.
• Document securement: Some carriers require drivers to note the number and type of tie‑downs used. Keep this documentation in your logbook or digital app.

By creating a routine and following FMCSA guidelines, you’ll reduce the risk of cargo shifting or securement failures. You’ll also demonstrate to inspectors and carriers that you take safety seriously.

Train the Rules Before the Road

If you’re new to trucking, the sheer volume of rules can seem overwhelming. ELDT Nation’s online ELDT theory training offers a structured way to learn securement fundamentals—including WLL calculations, tie‑down selection, and FMCSA requirements—through video lessons and interactive quizzes. Completing the theory portion online allows you to focus on hands‑on securement and hauling skills during your behind‑the‑wheel training.