Grain category

Grain draft survey refers to a method of calculating the actual weight of cargo by measuring the change in ship's draft before and after the loading and unloading of bulk grains (such as wheat, corn, soybeans, etc.), combined with ship information and port water density. It is suitable for the weight verification of cargo during bulk grain trade, especially for bulk carrier transportation where weighing each vehicle/bag is not feasible.

operating steps

1. Measure the draft on all six sides and record the draft readings at six locations on the ship, including the bow (F), midship (M), and stern (A), both on the left and right sides.

2. Calculate the average draft, and correct for the effects of trim and list,

3. Check the displacement. Based on the average draft, refer to the ship's hydrostatic table to obtain the current displacement.

4. Calibrate the port water density. Use a densitometer to measure the port water density

5. Calculate the weight of grain. After deducting the consumption of fuel and fresh water during loading and unloading, the net weight of grain is finally obtained.