General Securement Requirements
Cargo must be secured firmly on or within a vehicle by:
- Structures of adequate strength
- Dunnage (loose materials used to support and protect cargo) or Dunnage bags (inflatable bags intended to fill space between articles of cargo or between cargo and the wall of the vehicle)
- Shoring bars
- A combination of the above
Cargo Placement and Restraint
Articles of cargo that are likely to roll must be restrained by chocks, wedges, a cradle or other equivalent means to prevent rolling. They must remain fastened or secured while the vehicle is moving.
Articles of cargo placed beside each other and secured by tie-downs placed across the cargo must be:
- Placed in direct contact with each other
- Prevented from shifting toward each other while the vehicle is moving
Minimum Working-Load Limits
The aggregate working-load limit of the tie-downs used for an article or a group of articles of cargo must be at least 50 percent of the weight of that article or group of articles.
The aggregate working-load limit is the sum of:
- The working load limit for each tie-down that goes from an anchor point on the vehicle to an attachment point on an article of cargo (direct tie-down)
- The working-load limit for each tie-down that goes from an anchor point on the vehicle, through or over the cargo, and then attaches to another anchor point on the vehicle (indirect tie-down)
Minimum Number of Tie-Downs
The cargo-securement system used to secure cargo must consist of the minimum required number of tie-downs. This requirement is in addition to complying with rules concerning the aggregate working load limit.
When an article of cargo is not blocked or positioned to prevent movement in the forward direction, the number of tie-downs needed depends on the length and weight of the articles.
There must be at least:
- One tie-down for articles 1.52 metres or less in length, and 500 kilograms or less in weight
- Two tie-downs if the article is:
- 1.52 metres (five feet) or less in length and more than 500 kilograms (1,100 lb.) in weight
- Greater than 1.52 metres (five feet) but less than 3.04 metres (10 feet), regardless of weight
For example, one tie-down is required if the article of cargo is 1.52 metres in length (five feet) and does not exceed 500 kilograms (1,100 lb). If the article of cargo is greater than 1.52 metres in length but less than 3.04 metres, then two tie-downs would be needed, regardless of the weight.
When an article of cargo is not blocked or positioned to prevent forward movement and the item is longer than 3.04 metres (10 feet) in length, then it must be secured by:
- Two tie-downs for the for the first 3.04 metres (10 feet) of cargo
- One tie-down for each additional 3.04 metres (10 feet) or fraction thereof
If an article is blocked or braced by a header board, bulkhead or other articles that are adequately secured to prevent forward movement, then it must be secured by at least:
- One tie-down for every 3.04 metres of article length, or fraction thereof
Special Rule for Special-Purpose Vehicles
Generally, the basic rules concerning the minimum number of tie-downs do not apply to a vehicle transporting one or more articles of cargo such as machinery or manufactured structural items (for example, steel or concrete beams, crane booms, girders, trusses and so on), which because of their design, size, shape or weight must be secured by special methods.
However, any article of cargo carried on that vehicle must be adequately secured by devices that are capable of meeting the performance requirements and the working-load limit requirements.