What is a Load Lock?
A load lock (also called a cargo bar or load bar) is an adjustable bar that wedges between the interior walls of a dry van or reefer trailer to prevent cargo from shifting during transit. Load locks are one of the most fundamental cargo securement tools in trucking — used alongside straps, dunnage, and blocking to keep freight stable and protect it from damage. FMCSA cargo securement rules require that all freight withstand specific deceleration forces, and load locks are part of the system that makes this possible.
O Trucking Editorial Team
Trucking Industry Experts
Fact-Checked by O Trucking Dispatch Team
5+ years advising carriers on cargo securement compliance, equipment selection, and DOT inspection preparation
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O TruckingLoad Lock Bars: Definition & Guide (2026)
What Is a Load Lock?
A load lock is a telescoping bar — typically steel or aluminum — that adjusts to fit the interior width of a trailer. One end has a ratchet or spring-loaded mechanism that extends the bar until it presses firmly against both trailer walls. Rubber or composite pads on each end grip the wall surface and prevent the bar from slipping.
The concept is simple: place the bar behind (or in front of) a row of pallets to create a physical barrier that prevents the freight from sliding. When the driver brakes hard, turns sharply, or hits a pothole, the bar absorbs the force and keeps the cargo in place.
Load locks go by several names in the trucking industry:
- Load lock bar — The most common term
- Cargo bar — Used interchangeably with load lock
- Load bar — Shorter version of the same term
- Cargo securement bar — More formal/technical name
- Shoring beam — Specifically refers to E-track-mounted beams (heavier duty)
- Decking beam — Specifically refers to beams designed for double-stacking
While the terms are sometimes used interchangeably, there are important differences in strength, mounting method, and cost between friction-fit load locks, E-track shoring beams, and decking beams. We cover these differences in our load locks vs shoring beams vs decking beams guide.
Load Locks Are Not the Only Securement Method
Types of Load Locks
There are three main types of load locks used in trucking, each with different strength ratings, mounting methods, and price points:
| Type | WLL | Cost | Mounting | Best For |
|---|---|---|---|---|
| Friction-Fit Load Lock | 100-500 lbs | $15-$40 | Friction against walls | Light freight, gap filling, supplemental securement |
| E-Track Shoring Beam | 1,500-3,000 lbs | $50-$150 | E-track rail pins | Heavy freight, primary securement, compliance |
| Decking Beam | 2,000-4,000 lbs | $100-$250 | E-track or pocket track | Double-stacking pallets, maximizing trailer cube |
Friction-fit load locks are the most common type carried by owner-operators. They are inexpensive, quick to install (30 seconds), and require no special trailer hardware. However, their holding strength is limited — they rely entirely on friction against the trailer walls, and a hard enough impact can cause them to pop out.
E-track shoring beams are significantly stronger because they pin into E-track rails mounted on the trailer walls. The E-track provides a positive mechanical connection that does not depend on friction alone. Most newer dry van trailers come equipped with E-track from the factory. See our E-track cargo securement guide for full details.
Decking beams are specialized beams designed to create a second level inside the trailer. They sit on E-track or pocket track at a height that allows pallets to be stacked below and above the beam, effectively doubling the trailer's usable volume for lightweight freight. They are most common in LTL and distribution operations.
Load Lock Sizes: Choosing the Right Bar
Load lock bars are sold by their adjustable range — the minimum and maximum width they can span. Choosing the right size depends on your trailer's interior width:
| Bar Size Range | Fits Trailer Width | Common Use |
|---|---|---|
| 66"-76" | Straight trucks, box trucks | Narrower bodies, non-standard trailers |
| 85"-96" | Narrower trailers, some 48-foot trailers | Older or non-standard trailers |
| 92"-103" | Standard 53-foot trailers | Most popular — fits nearly all dry vans |
| 100"-114" | Extra-wide trailers, intermodal containers | Specialty applications |
The most popular size for standard 53-foot dry van trailers is the 92"-103" range. Standard dry van interiors are 98.5 to 102 inches wide, so a 92-103 inch bar fits with the adjustment mechanism in its mid-range — which is where it is strongest. For a detailed sizing guide with measurement instructions, see our load lock bar sizes guide.
Measure Your Trailer Before Buying
FMCSA Cargo Securement Compliance
FMCSA cargo securement rules (49 CFR 393, Subparts I and J) establish the minimum requirements for how freight must be secured inside commercial vehicles. These rules are enforced during DOT roadside inspections, and violations result in CSA points.
The key force resistance requirements are:
0.8g forward (braking) — The securement system must prevent the cargo from shifting under a force equal to 80% of the cargo's weight. For a 40,000 lb load, the system must withstand 32,000 lbs of forward force.
0.5g sideways (turning) — 50% of the cargo weight in side-to-side force. For 40,000 lbs, that is 20,000 lbs of lateral force resistance.
0.5g rearward (acceleration) — 50% of the cargo weight in rearward force. This prevents cargo from sliding toward the rear doors during acceleration.
A single friction-fit load lock with a 200-500 lb working load limit obviously cannot withstand 32,000 lbs of forward force. This is why load locks alone do not satisfy FMCSA requirements for heavy freight. They are supplemental tools that work within a broader securement system.
However, there is an important practical distinction: if the freight is tightly packed against the nose wall with no gaps, the headboard (front wall) of the trailer itself provides most of the forward resistance. The load locks then only need to prevent shifting in the gaps between pallets, which is a much lower force requirement. FMCSA recognizes this — the “50% rule” states that if cargo fills at least 50% of the trailer length and is in direct contact with the front end structure, fewer tie-downs are required.
For the complete FMCSA requirements and how to determine what securement system your specific freight needs, see our FMCSA cargo securement rules guide.
DOT Inspections Check Cargo Securement
Proper Load Lock Placement
Where you place load locks in the trailer matters as much as how many you use. Here are the best practices:
Behind the Last Row of Pallets (Toward Doors)
The most critical position. A load lock behind the last row of freight prevents it from sliding rearward toward the trailer doors during acceleration or when the doors are opened. This is the one position where every driver should use a load lock.
At Any Gap Between Pallet Rows
If there is a gap between two rows of pallets (common when the freight does not perfectly fill the trailer length), place a load lock at each gap. Gaps allow pallets to build momentum before hitting other pallets, increasing the impact force.
At Pallet Height, Not Floor Level
Position the load lock at the same height as the freight — typically 3 to 5 feet off the floor. A bar placed too low may slide under the pallets, and a bar placed too high may not contact the freight at all.
For detailed placement instructions including partial loads, multi-stop routes, and mixed freight scenarios, see our how to use load lock bars guide.
Steel vs Aluminum Load Lock Bars
Load lock bars come in steel and aluminum versions. Here is how they compare:
| Feature | Steel | Aluminum |
|---|---|---|
| Weight | 15-25 lbs | 8-15 lbs |
| WLL (shoring beam) | Up to 3,000 lbs | Up to 2,200 lbs |
| Cost | $15-$100 | $25-$150 |
| Corrosion | Can rust | Corrosion resistant |
| Durability | Excellent | Good |
| Best For | Heavy freight, best value | LTL, frequent handling |
For a comprehensive comparison including real-world durability data and specific use cases, see our steel vs aluminum load lock bars guide.
Load Locks vs Straps: When to Use Each
Load locks and ratchet straps serve different securement functions. They are complementary tools, not interchangeable alternatives:
Load locks prevent longitudinal movement — They keep freight from sliding forward or backward along the trailer's length. They are best at filling gaps and creating barriers.
Straps prevent lateral and vertical movement — Ratchet straps hold freight down and prevent it from tipping sideways. They are essential for tall, narrow loads, unevenly stacked freight, and anything that might topple.
Best practice: use both — A combination of load locks (for gap filling and longitudinal barrier) plus straps (for lateral restraint) provides comprehensive protection that is more likely to meet FMCSA requirements.
For a detailed comparison with scenarios showing when each is most effective, see our load locks vs straps comparison guide.
How Our Dispatch Team Helps with Cargo Securement
At O Trucking LLC, cargo securement compliance is part of our dispatching process:
Load-specific securement guidance
Different freight types require different securement approaches. When we book a load, we communicate any special securement requirements — whether the shipper expects load locks, straps, dunnage, or specific configurations. No surprises at the shipper's dock.
CSA score protection
Cargo securement violations during DOT inspections directly impact your CSA score and can increase your insurance rates. We help carriers understand securement requirements and avoid preventable violations that hurt their safety record.
Equipment recommendations
We advise carriers on what securement equipment to carry based on their typical freight types. A driver hauling grocery pallets needs different equipment than a driver hauling building materials or automotive parts. We help you build the right toolkit.
Related Resources
Pallet Jack
Tool for moving palletized freight
DOT Roadside Inspection Guide
What inspectors check and how to prepare
How to Check Your CSA Score
Monitor and improve your safety rating
Secure Pallet Jack in Trailer
Avoid CSA violations from unsecured equipment
Accessorial Charges List
Extra charges including securement fees
Reduce Trucking Costs
Smart cost reduction strategies
Load Lock Guide Collection
Load Locks vs Straps
Which is better for cargo securement?
How to Use Load Locks
Proper placement & installation
Load Lock Sizes
Right bar for your trailer
vs Shoring & Decking
Load locks vs shoring vs decking beams
E-Track Systems
Complete E-track securement guide
FMCSA Requirements
DOT rules for load locks
Steel vs Aluminum
Weight, strength & cost compared
Load Lock FAQ
Common questions about load locks, cargo bars, sizing, FMCSA compliance, and choosing the right securement for your trailer
What is a load lock in trucking?
A load lock (also called a cargo bar or load bar) is an adjustable bar that extends between the interior walls of a trailer to prevent cargo from shifting during transit. The bar presses against both walls with spring-loaded or ratchet tension, creating a physical barrier that keeps pallets, boxes, and other freight from sliding forward or backward. They are one of the most common cargo securement tools in dry van and reefer trucking alongside straps, dunnage, and blocking.
What is the difference between a load lock and a shoring beam?
A load lock (friction-fit cargo bar) is a telescoping bar with rubber feet that friction-fits between trailer walls. It costs $15-$40 and holds 100-500 lbs. A shoring beam (E-track beam) slots into E-track rails on the trailer walls and is secured with pins or clips. It costs $50-$150 and has a working load limit (WLL) of 1,500-3,000 lbs. A decking beam is a heavy-duty beam designed for vertical stacking — it creates a shelf to double-stack pallets. Shoring beams and decking beams are stronger and more reliable than friction-fit load locks but require E-track or pocket-track hardware in the trailer.
How many load locks do I need for a full trailer?
The number of load locks depends on your freight, trailer length, and how tightly the freight is packed. A general rule: use one load lock behind every unsecured gap between pallets that could allow shifting. For a typical full truckload of 24 pallets in a 53-foot trailer, drivers commonly use 2-4 load locks — one behind the first row of pallets, one in the middle if there is a gap, and one behind the last row before the doors. If the trailer is cube-packed with zero gaps, fewer bars may be needed. Always err on the side of more securement, not less.
Do load locks meet FMCSA cargo securement requirements?
Load locks can be part of an FMCSA-compliant cargo securement system, but they alone may not satisfy all requirements. FMCSA cargo securement rules (49 CFR 393) require that cargo be secured to withstand 0.8g forward deceleration, 0.5g sideways, and 0.5g rearward. A single friction-fit load lock typically cannot withstand 80% of the cargo weight in forward force. For heavy freight, load locks must be supplemented with straps, blocking, bracing, or a combination. Shoring beams with proper WLL ratings and E-track attachment can meet the requirements for moderate-weight cargo. See our FMCSA cargo securement guide for details.
What size load lock bar do I need for my trailer?
Load lock bars are sized by the interior width they span. Standard dry van trailers have interior widths of 98.5 to 102 inches. The most popular load lock sizes are 85 to 96 inches (adjustable) and 92 to 103 inches (adjustable). Before buying, measure your trailer's interior width at the widest point. The bar should extend enough to press firmly against both walls with the adjustment mechanism in its mid-range — not fully compressed or fully extended. Using a bar at its maximum extension reduces its holding strength.
Steel vs aluminum load lock bars — which is better?
Steel load lock bars are heavier (typically 15-25 lbs), stronger (working load limits up to 3,000 lbs for shoring beams), and cheaper. Aluminum bars are lighter (8-15 lbs), easier to handle, but have lower working load limits (typically 2,000-2,200 lbs) and cost more. For most trucking applications, steel provides better value — the weight difference (5-10 lbs) is negligible compared to a 45,000 lb load, and the extra strength provides a larger safety margin. Aluminum is preferred by drivers who handle many bars per day (LTL routes) where cumulative weight and ease of handling matter.
Can load locks damage my trailer walls?
Yes, if used improperly. Friction-fit load locks with metal ends (no rubber pads) can dent, scratch, or puncture trailer walls — especially older trailers with thinner panels. Always use load locks with rubber or composite end pads. Do not over-tighten ratchet-style bars, as excessive pressure can bow or dent the wall panel. Position bars at structural points (near rivets or support ribs) rather than in the center of unsupported panels. If your trailer has E-track, use E-track shoring beams instead of friction-fit bars — they distribute force into the track rather than the wall surface.
Need a Dispatch Team That Handles Securement Details?
Our dispatchers communicate cargo securement requirements before you pick up, help you stay DOT compliant, and protect your CSA score on every load.