Dockage is assessed and recorded to the nearest 0.1%.
Dockage is defined under the Canada Grain Act as “any material intermixed with a parcel of grain, other than kernels of grain of a standard of quality fixed by or under this Act for a grade of that grain, that must and can be separated from the parcel of grain before that grade can be assigned to the grain.” Dockage is removed by following the cleaning procedures described in this chapter.
The sample as it arrives is referred to as the uncleaned or dirty sample. Its weight is the gross weight of the sample. Dockage is assessed on the gross weight of the sample.
Dockage is assessed in two stages.
▲ Important: Dockage is not reported for samples grading
▲ Important: Wear gloves and a mask to handle any samples that you suspect may contain hazardous substances.
1. Set up the Carter dockage tester as follows:
| Feed control | #5 |
|---|---|
| Air control | Minimum #4 |
| Riddle | No. 25 or No. 1 |
| Top sieve | No. 6 buckwheat |
| Centre sieve | No. 5 buckwheat |
| Bottom sieve | No. 5 buckwheat |
| Sieve cleaner control | Off |
2. Using a Boerner-type divider, divide the uncleaned sample to obtain a representative portion.
3. Turn on the Carter dockage tester.
4. Pour the sample into the hopper.
5. After the sample has passed through the machine, turn on the sieve cleaner control for two to three seconds to remove kernels lodged in the sieve.
6. Turn off the dockage tester.
7. Lightly snap the retainer rod of the aspiration pan to loosen material gathered on the air screen.
8. Remove the aspiration pan.
9. Handpick large whole kernels of rye from the portion passing over the riddle and return them to the cleaned sample.
10. Determine dockage. Use the list under Composition of dockage.
Dockage includes
If the grade of a sample can be improved by additional cleaning, perform the cleaning and add the additional material to dockage. Cleaning for grade improvement can be done at any time after the cleaning assessment has been completed.
Procedures are summarized in the table which follows.
| Material to be removed | Equipment | Effect on composition of dockage |
|---|---|---|
| Broken kernels | No. 6 buckwheat hand sieve | If the weight of broken kernels is over the grade tolerance but is
|
Where a shipper requests special cleaning of a carlot of grain at a terminal or transfer elevator, and the elevator manager agrees, dockage material will be analyzed for the presence of grain. The percentage and grade of any grain contained in the dockage will be reported and elevator stocks will be adjusted on the basis of the analysis.
Agreement of the shipper and unload elevator must be conveyed to the Canadian Grain Commission in writing prior to the analysis being performed.
Example
95.0% Rye, No. l CW
4.0% Domestic Mustard Seed, No. 1 CAN Oriental
1.0% dockage