Cargo Floor and Running Load Limits: Structural Protection Calculations

Structural Limits

The cargo hold floor is designed to withstand a specific maximum load per unit area. Exceeding this can damage the floor panels or the structure beneath.

1. Floor Load Intensity

Defined as the mass per unit area. $ \text{Max Load Intensity} = \frac{\text{Mass}}{\text{Contact Area}} $

• Check: Ensure calculated intensity $\le$ Max Allowable Intensity ($kg/m^2$ or $lbs/ft^2$).

2. Running Load

Defined as the mass per unit length of the cargo hold. $ \text{Running Load} = \frac{\text{Mass}}{\text{Length of item}} $

• Check: Ensure calculated running load $\le$ Max Allowable Running Load ($kg/m$ or $lbs/in$).
• Usually critical for long, heavy items.

Shoring (Spreading the Load)

If a piece of cargo exceeds the floor load intensity limit (e.g., a heavy box with a small base), shoring is used to increase the contact area.

• Placing strict wooden planks or a pallet under the load distributes the weight over a larger area.

$ \text{Required Area} = \frac{\text{Mass}}{\text{Max Floor Load Limit}} $