Calculators

The "Calculators" page gathers eight offline calculators for cargo and engine work. All of them are for training and cross-checking only: the ship’s approved software (the loading computer, the calibration tables, the custody-transfer system) and your company procedures always come first. The three loading screens show a red banner on screen and in print: "Cross-check only. Not a loading instrument." Every calculator remembers what you typed on this device, and most carry a source note saying which standard or formula they use and when it was checked.

"Cargo & bunker quantity": the volume correction factor (VCF) from density at 15 °C and temperature (metric, Table 54) or API gravity and °F (US, Table 6), for products and fuel, crude oil or lube oil, plus the weight correction factor (Table 56). Below it, a tank-by-tank quantity: add tanks with TOV, free water and temperature, choose the purpose ("Bunkers received", "ROB", "OBQ" or "Cargo figure"), and read GOV, GSV, weight in air and weight in vacuum. A density outside the standard’s range is flagged as not valid.

"Ullage / sounding table": type or paste a tank’s calibration table once (one row per line: level, volume), name it, choose ullage or sounding and cm or m, and "Save". Then enter the observed level and a trim or list correction from the ship’s own correction table to read the volume. The tool interpolates between rows and never reads outside the table.

"LNG / LPG quantity & boil-off": LNG mass and energy from volume, density and calorific value; boil-off rate from two gaugings with no cargo moved in between, or the daily boil-off from a design rate; and LPG liquid plus vapour tonnes for propane, n-butane, propylene, ammonia or VCM. Estimates only — custody transfer uses the approved CTMS and the terminal’s figures.

"Squat, UKC & list": the Barrass squat estimate in open water, confined water or a channel with blockage factor, the dynamic under-keel clearance (depth minus draft minus squat) against the minimum UKC from your company or port policy, with a green or red verdict; and the angle of list from a transverse weight shift.

"ECA fuel changeover": how many hours (and miles) before the ECA boundary to start changing over so the fuel at the engine is below the 0.10 per cent limit, from the mixing volume, consumption, the sulphur of both fuels and a safety margin, with a curve of sulphur falling over time. Follow the ship’s written changeover procedure and record the times, positions and tank quantities in the log book.

"Draft survey": six draft readings, the distances of the marks from the perpendiculars, the two hydrostatic rows either side of the quarter mean, MTC at plus and minus 0.5 m, table and dock-water density, deductibles, lightship and constant — then displacement, net displacement and cargo on board, with every step listed as on a survey sheet. Save an "Initial" and a "Final" survey on this device and the tool gives the cargo loaded or discharged between them.

"Trim & drafts after loading" and "Stability (GM)" share one weights table (weight, LCG, VCG and the free-surface moment of each slack tank, with Lightship and Constant rows ready). Trim gives displacement, LCG, trimming moment, trim and the forward and aft drafts from your booklet’s LCB, MCTC and LCF, and warns in red if the ship is trimmed by the head. Stability gives KG, GM solid, the free-surface correction and GM fluid, and checks it against the 0.15 m minimum of the IMO 2008 IS Code — passing that is not enough on its own; the full criteria can only be checked in the stability booklet or the loading computer.

Everyone, on every plan including Free. Nothing here needs internet.

1. Open "Calculators" from the Calculators group of the menu, then tap the calculator you need.
2. Read the amber caution or the red cross-check banner at the top and the "Units and signs used on this screen" box, so your signs match the booklet (for example trim + by the stern, LCG + forward of midships).
3. Type the figures from the booklet, the BDN or the tables into the number boxes; the result updates as you type and shows the formula used.
4. In the draft survey, trim and stability screens tap "Print / PDF" to keep a copy; in the draft survey tap "Save on this device" to keep an initial or final survey.
5. Tap "Calculators" at the top to go back to the list.

• Number boxes open the number keypad; speak-to-type skips number boxes, so type the figures.
• Compare like with like before signing a bunker delivery note: the note states the figure in air or in vacuum, and the quantity screen shows both.
• If your booklet measures LCB from the aft perpendicular, subtract half the LBP first — the sign box on the trim screen gives an example.
• Halving speed cuts squat to about a quarter; the squat screen shows the figure at half speed.

• Cross-check only. Not a loading instrument. Shear forces, bending moments and the full intact stability criteria are not checked here — only the class-approved loading computer and the stability booklet do that.
• The ullage tool applies no trim or list correction of its own; take it from the ship’s correction tables. The gas tool uses the ideal-gas law with no compressibility factor.
• Tank tables, saved surveys, the weights table and your last inputs are kept on this device only (and in your device backup); they are not in the ship file and not synced to other phones.
• On the Free plan a print from the loading pack counts as one of your 3 main PDFs a month, watermarked; paid plans and the trial print without limits.