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 the following 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 graded
▲ 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 | #4 |
|---|---|
| Air control | #3 |
| Riddle | No. 000 |
| Top sieve | Blank tray |
| Centre sieve | None |
| Bottom sieve | None |
| Sieve cleaner control | Off |
2. You need the No. 4.5 round-hole sieve, and one wire sieve, depending on the size of the flaxseed or solin and the nature of the material to be removed.
| Round-hole sieves | Wire sieves |
|---|---|
| No. 4.5 | No. 4x14 |
| No. 3x16 |
3. Using a Boerner-type divider, divide the uncleaned sample to obtain a representative portion.
4. For hand sieving use approximately 250 g per sieving
5. Combine the separated 250-g portions.
6. Turn on the Carter dockage tester.
7. Pour the entire working sample into the hopper.
8. After the sample has passed through the machine, turn off the machine.
9. Lightly snap the retainer rod of the aspiration pan to loosen material gathered on the air screen.
10. Using a Boerner-type divider, divide not less than 20 g from the cleaned working sample.
11. From the 20-g portion, determine the percentage by weight of inseparable material.
12. Determine dockage, using the list under Composition of dockage.
Dockage includes
Primary samples are commercially clean when the net dockage does not exceed 2.5% of the sample weight. Commercially clean primary samples can have up to 0.5% for broken and reasonably sound flaxseed or solin deducted from the gross weight of the dockage.
In not commercially clean primary samples there is no allowance for broken and reasonably sound flaxseed or solin.
In sample grades, inseparable admixture is not added to dockage. Where the inseparable material exceeds 2.0% of the sample by weight, the admixture becomes a reason for the sample grade and is recorded in remarks.
In samples that grade Rejected (basic grade) Account Stones, dockage includes inseparable material handpicked from the clean sample up to the tolerance.
If the grade of a delivery 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.
| Material to be removed | Equipment | Effect on composition of dockage |
|---|---|---|
| Inseparable material | No. 5 round-hole hand sieve | The material passing through the sieve is included in the dockage. Not more than 5.0% of sound flaxseed or solin may be removed for each single grade improvement achieved. |
| Lightweight material | Carter dockage tester, with Feed control at #4 and air control at #4.5 Note: The material originally removed by aspiration is to be reconstituted back into the sample prior to cleaning for improvement. |
The material removed, including damaged seed, is included in the dockage. Not more than 5.0% of sound flaxseed or solin may be removed from the cleaned sample for each single grade improvement achieved. |
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 CGC in writing prior to the analysis being performed.