Chemical Tankers / Day 4 / Day 4 Topic 2 Cargo Quantification
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Cargo Calculations
dVCF = 1 - 0.9662 = 0.0338
dT |
= 140 - 60 = 80 |
VCF = 0.0338 = 0.0004225 80
0.0004225 x 0.9492 = 0.00040104 (Corr oF)
0.00040104 x 1.8 = 0.00072 (Corr oC)
Strictly speaking, this is not completely accurate as the relationship is not linear, but it is close enough for calculation purposes
Cargo Calculations
It is easier to convert Lbs / Gall to L/W
There is an official ASTM Conversion Factor:
L/W = Lbs / Gall x 0.11982643
If you have two L/W values from a table, you also have the temp interval and can easily calculate a Correction Factor per degree
Tables may be given in Kg / l (Kilogram per Litre)
Cargo Calculations
Example 6: From table: Lbs/Gall |
60oF: 6.69 |
|
90oF: 6.58 |
Lbs/Gall 6.69 x 0.11982643 = L/W 0.8016 Lbs/Gall 6.58 x 0.11982643 = L/W 0.7889
dT = 90 - 60 = 30oF
dL/W = 0.8016 - 0.7889 = 0.0127
dL/W = 0.0127 = 0.000423 dT 30
0.000423 x 1.8 = 0.00076 (Corr per oC)
Cargo Calculations
Cargo Discrepancies:
Ship’s Load Figure against Bill of Lading Figure
+ or - 0.5%, calculated against the B/L figure
If B/L is not available, protest against “Provisional Shore Figure” and, if figures become available later, issue retro-protest through Agent
Some charterers require Masters to issue letter of protest as per their specific percentage requirements with may be less than 0.5
Cargo Calculations
•Form
•Cargo Quantity Discrepancy
•Protest.
Cargo Calculations
Example 7:
Ship’s Load Figure : 994.507 mt
Bill of Lading Figure: 1000.025 mt
Difference: 5.518 mt ( - 0.552 % )
Issue Cargo Quantity Discrepancy Protest
Cargo Calculations
Example 8:
Ship’s Load Figure : 101.955 mt
Bill of Lading Figure: 100.032 mt
Difference: 1.923 mt ( + 1.922 % )
Issue Cargo Quantity Discrepancy Protest
Cargo Calculations
Example 9:
Ship’s Load Figure: 497.798 mt
Bill of Lading Figure: 499.993 mt
Difference: 2.195 mt ( - 0.439 % )
No protest to be issued, difference is within percentage (But note how actual tonnage is higher than in the last example)
Cargo Calculations
Example 10:
Ship’s Load Figure: |
995.302 mt |
Surveyor’s Shore Figure : 1001.766 mt (No B/L available)
Difference: 6.464 mt ( - 0.645 % )
Protest against Provisional Figure - issue Retro-Protest through Agent if B/L available in time
Cargo Calculations
Short Loading:
Ship’s Load Figure against Nominated Figure ( due consideration must be given to Option and Load range)
Establish: |
a) Option: ( Owner’s / Charterer’s /MinMax / other ) |
b) Practical range: (Capacity / density / max possible load )
c) Issue Notice of Readiness for max cargo