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Introduction
We have developed spreadsheet-based files that have customised cargo work calculations for a crude oil and product tankers. Our standalone products are designed for the business of shipping cargo (chemicals, oil or products) via shipping vehicles (tankers) or storing them ashore or in floating storage units (FPSO). We prefer to work with Microsoft Excel (images below are snapshots of Lotus 1-2-3 files). The latest products are standalone with a backend database storing the manual entries for each port of call. The database can be used to produce all kinds of MLI statistical analysis.
Entries by user would be:
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Cargo Ullages and temperatures tank-wise;
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Gauge readings/Soundings of ballast
tks;
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Fuel/FW Tks Qty;
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Sp. Gr. of Sea Water;
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Interface sounding for free water,
if any;
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V.E.F.;
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OBQ/Slops on board, if any;
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API and/or Density;
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Tables required (6, 24 or 54 A/B);
(selectable by mouse click)
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etc.
Make your own spreadsheets or standalone projects.
Download the add-in
dll(s) with all the functions you need for
the tanker industry.
The results are transferred to the following with
tabulated and/or chart representations and may be printed at will
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stress pages;
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Record of V.E.F. for last 10, 20 and
30 voyages;
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Charterer's and Owner's forms, viz.
Letters of protest for BL discrepancies, delays, free water, port log, Ullage Report,
Stowage Plan;
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Etc.
Hydrostatic calculation (draft
survey) with hog or sag deflection is also included.
Customised menus allow macros to run
for:
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Online registration of tank volumes
where such hardware fitted, (We can undertake turnkey installation of hardware at
dry-dock);
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New Reports;
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Backsolve to
required - Nett MT, Barrels, DWT or Draft;
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Change SW density - same cargo/ballast;
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A scratchpad for quick conversion from
degrees F'ht to C, Ft to M and vice versa with resultant DWT for that Ft or M.
Also included is the extremely powerful
and much used (by the Chief Officers), add-in called Solver.
Solver provides an optimal solution to various loading/discharging scenarios in a
matter of seconds.
Example:
You have a nominated BL Qtty of 630,000 Nett Barrels of Oseberg Blend to load from
Sture (Salt water) for discharge at Immingham (brackish). With the given bunker ROBs
and load temperatures, draft restrictions, Solver can find a loading distribution
to satisfy the given constraints which would be - no list, even keel arrival, volumes
<= 98%, minimum stresses, etc.
We offer to write a similar customized spreadsheet for
a fee, for any tanker operator/owner who may get in touch with us by e-mail for a
sample spreadsheet at: 
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Trim & Stability
 The following is a picture of the bottom half of the
"Trim/Stab" page in the Lotus Workbook. The unseen portion has the data for Provisions,
Constant, FW, Ballast, Fuel / Diesel and Cargo.
KG, LCG and Inertia Moments are tabled for each and the
results are displayed as seen below.
Results of the "Stress" page are also incorporated.
An attempt is made to reflect the actual draft taking
into consideration the deflection due to stresses vis-a-vis the straight girder theoretical
results. This is useful in cases of sailing in shallow waters where the additional
max. draft due to stresses must be taken into consideration, as too the squat.
Click on Image To Magnify It
Also calculated, is the loss of GM upon touching the
blocks during dry-docking.
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Back Solve
You may select an item from the list above to backsolve
to.
Example:
You may need to know, with the given the cargo API/Density and temperatures (which
would be entered in the "Ull Rep" page and the Constant / Fuel / FW / Ballast conditions
(entered in the "C Fuel FW B" page), and the OBQ ("Wedge" page) and Slops onboard
("SlopCert" page), what the cargo loadable would be for a "Mean-Draft" of 12.192 M
Sea Water?
Backsolver would obtain results for you in a matter of
seconds.
The
distribution of the cargo tank-wise with the
resultant drafts, trim and list would not
usually be satisfactory. For a satisfactory
distribution, the user would
Click on Image To Magnify It
need to use
the "Solver" facility.
Nevertheless, Backsolver serves the important purpose
of a quickfire answer to quickfire questions that are posed ever so often to the vessel
by the charterers / brokers. The distribution (stowage plan) may be obtained more leisurely
by using the Solver facility.
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Solver
Solver is an add-in feature that comes free with Excel
(Tools menu). Solver is an Add-in for Lotus 123 and licenced by Frontline Systems.
We provide this add-in.
In the problem above -
The set cell is "AVG-ALL STRESS", which is a cell in
the spreadsheet that represents the average of all the BM and Shear Forces. The demand
is to "MINIMISE" the stresses.
The Changeable (Variable) cells are "CARGO GAUGES", which
are the MMC Ullages in the table. Additional variable cells may be added, viz. Ballast
Tank Gauges.
The constraints are many - (up to 100 constraints may
be included in this part of the dialog box). The constraints not seen in the picture
above are:
Click on Image To Magnify It
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Volumes of each of the other cargo
tanks <=98%
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Heel Moments = 0
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Deadweight <=96,510 (Summer DWT)
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Nett Barrels = 631,890 (B/L nomination
630,000 * clean VEF of 1.003)
Solver should be able to come up with an optimal solution
in a matter of minutes, if not in seconds.
In the example above, the results (solution), will provide
a possible loading pattern keeping to the SetCell demand for a minimised average
of all stresses, a cargo quantity of 631,890 Nett Barrels, No List, aft trim=0.2M,
etc.
Any Chief Officer would be delighted to use this add-in
and it would be redundant to point out that the cost of the add-in is well worth the
time saved in this aspect of loading/discharging operations.
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Hydrostatic Calculation
Facility is provided to compute the weight of the cargo
on board by hydrostatic calculations from the draft gauges as well as from the observed
drafts at the draft marks.
Click on Image To Magnify It
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Sample Prints/Wkb Pages
To list of a few -
Make your own spreadsheets or standalone projects.
Download the add-in
dll(s) with all the functions you need for the tanker industry.
Requirements
Top Of Page
Additional Information
We have undertaken smaller projects too - Ullage reports
only for crude and product tankers with results exported to charterer's and owner's
standard forms (ship specific data for tank volumes with trim and heel correction,
stability, stresses and hydrostatic calculations, etc. not included).
- For
Shipping Companies -
Engine Department.
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