SailorNotebook
All notebooks

Contents

Stability & Cargo

Soundings, drafts, trim, list and the cargo figure, from the tank to the survey.

15 pagesSecond Officer – Master

  1. Second Officer

    1.Sounding from an ullage: correct it first, then read acrossCorrect the gauged ullage for trim first, then sounding = reference height − corrected ullage; the two together always make up the reference height.
  2. 2.Gross Standard Volume: free water out, then the temperature correctionTake the free water off the TOV first (GOV), then multiply by the VCF; GSV = (TOV − free water) × VCF, the oil at the standard 15 °C.

  3. Chief Officer

    3.Loading to the marks in dock water (FWA and DWA)In lighter dock water she may load deeper by DWA = FWA × (1.025 − dock density) ÷ 0.025; at sea she rises back to her Summer mark.
  4. 4.Final draft from TPC: everything that comes on board sinks herAdd every tonne that comes on board, bunkers included, and divide by the TPC: sinkage (cm) = w ÷ TPC; final mean draft = present mean draft + sinkage.
  5. 5.Change of trim from a tank transfer (MCTC and LCF)Change of trim = weight × distance moved ÷ MCTC; the ends share it about the centre of flotation (LCF), never all at one end.
  6. 6.GM with a slack tank: the free surface correctionA slack tank costs GM as if G rose by FSC = (l × b³ ÷ 12) × liquid density ÷ displacement; fluid GM = solid GM − FSC.
  7. 7.List from a wing-tank transferList: tan θ = (weight × distance moved) ÷ (displacement × fluid GM), with the distance measured tank centre to tank centre and the GM always the fluid one.
  8. 8.The cargo figure: from the ullage totals to weight in airFree water out (GOV), the VCF to 15 °C (GSV); then weight in air = GSV × (density at 15 °C − 0.0011): the figure ship and terminal compare.
  9. 9.Two chains on one certificate: the metric chain to weight in airRead down one column: m³ go with Table 54B and the density at 15 °C; Table 6B and the 60/60 °F relative density belong to the barrels.
  10. 10.Vessel Experience Factor (VEF): the ship's figures against the shore'sVEF = Σ ship ÷ Σ shore over the qualifying voyages; at the next loading, divide the ship's figure by it before comparing; it explains a difference, it does not replace the B/L.
  11. 11.The ship's figure against the Bill of Lading, in per centCompare like with like, the ship's GSV against the Bill of Lading; take the difference on the Bill of Lading; keep the sign, because minus means the ship is short.
  12. 12.Displacement in dock water: correct the table figure for densityThe drafts fix the immersed volume and the tables weigh it in their own water; corrected displacement = table displacement × density alongside ÷ table density; lighter water, smaller displacement.
  13. 13.Draft survey: how much cargo is on boardCargo = displacement − lightship − every deductible on board; the drafts weigh everything, so anything you forget to deduct is reported as cargo.

  14. Master

    14.The ship's constant on a survey: what she displaces but cannot nameConstant = displacement − lightship − everything declared on board at the survey; it should come out about the same on every survey.
  15. 15.Loading to the marks when she will cross into the Winter zoneStart from the Winter mark, the zone she meets at the boundary; add only what she burns getting there; deepest sailing draught = Winter draught + consumption ÷ TPC.