How to Use Load Lock Bars: Step-by-Step Cargo Securement
A load lock bar is one of the simplest and most effective tools for preventing cargo from shifting inside a dry van trailer. But “simple” does not mean foolproof. Improper installation, wrong height placement, or using the incorrect type of bar for your cargo can lead to load shifts, damaged freight, and FMCSA violations. This guide walks through every step of proper load lock bar usage, from selecting the right bar to positioning it correctly for different cargo configurations.
2-5 Min
Install Time Per Bar
100-250 lbs
Typical Holding Force
$20-$80
Cost Per Bar
2/3 Height
Ideal Placement Point
O Trucking Editorial Team
Trucking Industry Experts
Fact-Checked by O Trucking Dispatch Team
5+ years coordinating dry van loads, verifying cargo securement methods, and ensuring FMCSA compliance for owner-operators hauling LTL and FTL freight
Sources:
This article was written by the O Trucking editorial team with 9+ years of combined trucking industry experience. Learn more about us.
O TruckingHow to Use Load Lock Bars (2026)
What Are Load Lock Bars?
Load lock bars (also called cargo bars, load bars, or decking bars) are adjustable metal poles that press against the interior walls of a trailer to create a physical barrier that prevents freight from moving forward or backward during transit. They work on a simple principle: the bar extends to fit the width of the trailer and applies outward pressure against both sidewalls, creating friction that holds the bar — and the cargo behind it — in place.
Load lock bars are not designed to hold back enormous force. A standard bar supports approximately 100 to 250 pounds of horizontal pressure depending on the model. They are best suited for preventing light to medium loads from shifting, not for restraining heavy pallets that could generate thousands of pounds of force during a hard stop. Understanding this limitation is critical for using load locks safely and in compliance with FMCSA cargo securement regulations.
Every dry van driver should carry at least four to six load lock bars on the truck at all times. Many shippers and receivers require them as part of their loading procedures, and showing up without bars can delay your pickup or result in a refused load.
Spring-Loaded vs Ratchet Load Lock Bars
There are two primary mechanisms for load lock bars: spring-loaded and ratchet-style. Each has distinct advantages and trade-offs. Understanding both helps you pick the right tool for your freight type and budget.
| Feature | Spring-Loaded | Ratchet |
|---|---|---|
| Mechanism | Internal coil spring | Manual ratchet crank |
| Install speed | 30-60 seconds | 1-3 minutes |
| Holding force | 100-150 lbs | 150-250 lbs |
| Adjustability | Spring tension only | Precise width control |
| Cost | $20-$40 | $40-$80 |
| Durability | Springs weaken over time | Ratchet lasts longer |
| Best for | Light freight, quick installs | Heavier pallets, mixed loads |
Spring-loaded bars are the most common in the industry. You compress the bar, position it between the trailer walls, and release it. The internal spring pushes outward against both walls, holding the bar in place through friction. They are fast to install and affordable, but the spring tension degrades with repeated use. After six months to a year of heavy use, you will notice the spring does not grip as tightly. Replace them when they start slipping under light pressure.
Ratchet bars use a manual crank mechanism similar to a ratchet strap tensioner. You position the bar roughly at trailer width, then crank the ratchet to extend it precisely until it presses firmly against both walls. Ratchet bars offer significantly more holding force (150-250 lbs) and maintain consistent tension over their lifespan. The trade-off is installation time and higher cost. For drivers hauling mixed pallets, beverage loads, or any freight where a small shift could cause damage, ratchet bars are worth the investment.
Step-by-Step Installation Guide
Follow these steps every time you install a load lock bar. Rushing through the process or skipping steps leads to bars that pop out during transit — which means your cargo shifts and you are liable for the damage.
Inspect the Bar Before Use
Check the rubber end caps for wear, cracks, or missing pieces. The rubber feet are what grip the trailer wall — worn-out feet mean the bar will slip. On spring-loaded bars, compress and release the bar several times to verify the spring has adequate tension. On ratchet bars, confirm the ratchet mechanism cranks smoothly and locks at each click without slipping backward.
Check the Trailer Walls
Look at the interior sidewalls where the bar will contact. The walls need to be clean, dry, and free of ice, grease, or debris. Load lock bars grip through friction — any contamination on the wall surface reduces holding force. Also check the logistics track (the metal rail running along the sidewall) if you plan to seat the bar in it. Bent or damaged track sections will not hold a bar properly.
Position at the Correct Height
Place the bar at approximately two-thirds of the cargo height. For a pallet stack that is 60 inches tall, position the bar at about 40 inches. This creates the most effective resistance against forward and backward movement. Placing the bar too high means cargo can slide underneath; too low means the top of the load can topple over the bar.
Seat the End Caps Firmly
For spring-loaded bars: compress the bar, place one rubber end cap against one wall, and position the other cap against the opposite wall. Release slowly, letting the spring push outward. For ratchet bars: position the bar loosely between the walls, then crank the ratchet until you feel solid resistance on both sides. The bar should not wobble, rotate, or move when you push on it with your hand.
Verify the Hold
Push on the bar from both the front and back directions. It should not move, shift, or rotate. If you can move the bar with moderate hand pressure, it will not survive a hard brake at highway speed. Reposition or replace the bar. Then give the cargo behind the bar a firm push to confirm the bar is actually contacting the freight and not floating with a gap between the bar and the cargo face.
Close the Trailer Doors and Recheck
After closing the trailer doors, drive forward 50 feet and apply a firm brake. Stop, open the doors, and verify the bars are still in position and the cargo has not shifted. This “brake test” is the final confirmation that your securement will hold during transit. If anything moved, reposition the bars and add additional bars or supplemental securement as needed.
Use the Logistics Track When Available
Proper Placement Height
Height placement is the single most important factor in load lock bar effectiveness. The ideal height depends on the cargo height, weight distribution, and center of gravity. Here are the general rules:
| Cargo Height | Bar Placement Height | Number of Bars | Notes |
|---|---|---|---|
| Under 36" | 24" | 1 per row | Low pallets, floor-loaded boxes |
| 36"-60" | 36"-40" | 1-2 per row | Standard pallet stacks |
| 60"-84" | 48" + 72" | 2 per row | Double-stacked pallets, tall loads |
| 84"+ | 36" + 60" + 84" | 3 per row | Floor-to-ceiling loads |
For tall loads (over 60 inches), always use two bars at different heights rather than a single bar in the middle. The lower bar prevents the base from sliding forward while the upper bar stops the top from toppling. Using only one bar at the midpoint creates a pivot point that can actually make the load more likely to tip rather than less.
Positioning for Different Cargo Types
Not all cargo is loaded the same way. The position and number of load lock bars changes based on how the freight is configured inside the trailer.
Full Truckload (Palletized)
When the trailer is full of palletized freight loaded nose-to-tail, the main risk is the last row of pallets shifting backward toward the doors. Place at least two bars behind the last row of pallets: one at half the pallet height and one at three-quarters height. If there is a significant gap between the last pallet and the trailer doors, use additional bars at intervals to fill the void space. The gap between the rear cargo face and the doors is where most load shifts originate.
Partial Load (LTL or Multi-Stop)
Partial loads are where load locks become essential. When the trailer is not completely full, cargo can shift in multiple directions. Place bars behind each separate group of freight to create compartments. For a half-loaded trailer with freight in the nose, install bars behind the cargo wall at two heights, plus place bars at the midpoint of any empty span to prevent the load from tipping if the freight stack is tall relative to its base.
Floor-Loaded Boxes
Loose boxes stacked floor-to-ceiling require the most load lock bars. Without pallets to provide a rigid structure, individual boxes can shift in any direction. Place bars at every 24-36 inches of vertical height and at each longitudinal break point in the box wall. Plan on using 6-10 bars minimum for a full floor-loaded trailer. Many experienced drivers also place cardboard or plywood between the bars and the box faces to distribute pressure evenly.
Cylindrical or Irregularly Shaped Freight
Drums, rolls, and cylindrical items are particularly prone to rolling. Load lock bars alone are usually insufficient for round cargo — they need to be combined with chocks, dunnage, or straps. If you must use load locks with cylindrical freight, position the bar at the widest point of the cylinder and use two bars to create a V-shaped cradle that resists rolling in both directions. Always supplement with additional securement for round freight.
How Many Load Lock Bars Do You Need?
The number of bars you need depends on the load configuration, trailer length, and how much empty space exists in the trailer. Here is a general guideline:
Minimum Bar Count by Load Type
- Full truckload, palletized: 2-4 bars
- Partial load (half trailer): 3-5 bars
- Multi-stop delivery: 4-8 bars
- Floor-loaded boxes: 6-12 bars
- Lightweight/fragile cargo: 6-10 bars
- Always carry on truck: 8-12 bars minimum
Carry More Than You Think You Need
Common Load Lock Bar Mistakes
These are the errors we see most often. Each one can lead to load shifts, damaged freight, cargo claims, or FMCSA violations during a roadside inspection.
Using worn-out bars. Springs lose tension over time. If the bar does not grip firmly when you release it, it will not hold during a 60 mph emergency stop. Replace bars when the rubber feet are cracked, the spring feels weak, or the bar wobbles after installation.
Placing at the wrong height. A bar placed too high lets cargo slide underneath. A bar placed too low allows the top of the load to tip over. The two-thirds rule (bar at 2/3 of cargo height) is the standard for single-bar placement.
Leaving gaps between the bar and cargo. The bar must contact the freight face. A bar floating 6 inches in front of the cargo provides zero resistance until the freight has already shifted 6 inches — which is enough to cause damage or cascade the entire load.
Using load locks for heavy freight. Load lock bars hold 100-250 lbs of horizontal force. A 2,000-pound pallet decelerating from 65 mph can generate several thousand pounds of forward force. For heavy freight, load locks are supplemental — you need straps, chains, or bulkhead walls as primary securement.
Relying on a single bar for the entire load. One bar is almost never enough. Even for a tightly packed full truckload, you should use at least two bars at different heights behind the last row. For partial loads, you need bars at each cargo break point.
Not checking bars after stops. Temperature changes, vibration, and repeated braking can cause bars to work loose during a trip. Check your load lock bars at every stop — fuel stops, rest areas, delivery points. If a bar has shifted, reset it before continuing.
FMCSA Cargo Securement Requirements
The FMCSA cargo securement rules (49 CFR Part 393, Subpart I) require that all cargo be “immobilized or secured” to prevent shifting during transit. The regulations do not specifically mandate load lock bars, but they require that whatever method you use must prevent the cargo from shifting or falling in any direction.
Under the FMCSA rules, cargo must be restrained to withstand the following forces: 0.8g in the forward direction (equal to 80% of the cargo weight pushing forward during a hard stop), 0.5g in the rearward direction, and 0.5g laterally (side to side). A single load lock bar with 150 lbs of holding force cannot meet these requirements for anything heavier than about 190 lbs of cargo in the forward direction.
This means load lock bars should be viewed as supplemental securement for heavy freight, not primary securement. They are effective as primary securement only for light loads where the total force of the cargo during a hard stop does not exceed the bar's rated holding capacity. For most palletized freight, you need to combine load locks with other methods: straps, friction mats, dunnage, or the trailer walls themselves (when the freight is tight wall-to-wall).
Roadside Inspections Check Cargo Securement
How Our Team Handles Load Securement
At O Trucking LLC, cargo securement is part of every load we dispatch:
Pre-dispatch securement planning
Before a driver arrives at pickup, we communicate the load details: freight type, weight, number of pallets, and any special securement requirements from the shipper. This ensures the driver brings adequate load lock bars, straps, and dunnage for the specific cargo.
Securement verification at pickup
Our drivers photograph the loaded trailer with securement in place before departing the shipper. This documentation protects against false damage claims and verifies that proper securement was applied. We review these photos and provide guidance if additional securement is needed.
Need a Dispatch Team That Takes Cargo Securement Seriously?
Our dispatchers communicate load details before pickup so drivers arrive with the right securement equipment. Proper load locks, proper placement, zero cargo claims.