The Securement System
and its Components

Some tiedowns pass over or through the cargo, creating a downward force that increases the effect of friction between the cargo and the deck, thereby restraining the cargo. These are called indirect tiedowns In many cases, this friction between the load and deck is the principal factor affecting load securement (although friction alone is never enough to secure a load).

Tiedown construction and maintenance

Tiedowns and/or their associated connectors or attachment mechanisms (except for steel strapping) must be designed, constructed, and maintained so that the driver can tighten them. All components of each tiedown must be in proper working order, with no defects that reduce the working load limit:

• No knots, cracks, cuts, or other obvious damage.

Containing, Immobilizing, and Securing Cargo
Aggregate working load limit

The sum of the working load limits of each device used to secure an article on a vehicle is called the aggregate working load limit. Knowing the aggregate WLL will allow you to determine the minimum number of tiedowns required for your cargo, based on the weight of the cargo.

How do you calculate the aggregate WLL?

To calculate the aggregate WLL, add together:

• 50% of the WLL of each direct tiedown (tiedowns that go from an anchor point on the vehicle to an attachment point on an article of cargo); AND
• 100% of the WLL of each indirect tiedown (tiedowns that go from an anchor point on the vehicle, through, over, or around the cargo and then attach to another anchor point on the vehicle).

Examples:
50% of A
+ 50% of B
+ 50% of C
+ 50% of D
= Aggregate WLL

100% of A
+ 100% of B
= Aggregate WLL

100% of A
+ 100% of B
= Aggregate WLL

Dressed Lumber and Similar Building Materials
Positioning and securing bundles

Choose one of two options for positioning bundles placed side by side on a platform vehicle

Option #1: Place bundles in direct contact with each other.

Option #2: Provide a means (such as dunnage or blocking) to prevent the bundles from shifting towards each other.
Bundles carried in a closed vehicle should be immobilized or contained in accordance with the general cargo
securement requirements.

REFERENCE
Frequently Asked Questions (FAQs)

Are tarps required?
They are not specifically required under the federal rules but they may be necessary to contain certain types of loads and some states and/or your company may require their use.

Can cargo straps go around the outside of the rub rails
No, the rub rail is designed to safeguard the straps, not support them. All straps should be outed in-board of the rub rails whenever possible.

Do I have to secure cargo in my dry van?
Yes, all cargo and equipment must be secured against movement, regardless of vehicle type.

We haul heavy equipment. Do accessories like hydraulic buckets, shovels, and blades have to be secured?
Yes, you must completely lower and secure all accessory equipment to the vehicle.