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Loadicator / Loading Computer

Learn the loadicator: ship loading computer that checks stability, shear force, bending moment, GM, sailing draughts and deadweight before departure.

Published by ChartandKeel Updated

1. What Is a Loadicator?

  • Most modern cargo ships are now equipped with loadicator systems or a loading computer with appropriate software.
  • It is usually a conveniently sited visual display for the Master and the loading officers.
  • It is gainfully employed on Ro-Ro vessels, bulk carriers, tankers and other cargo ships.
  • Because the stability and strength of a ship depend on how weight is distributed, the loadicator allows the loading plan to be tested before and during cargo operations.

A decision-support tool. The loadicator does not replace the stability booklet — it quickly evaluates a proposed loading condition against the ship's approved stability and longitudinal strength limits, so the Master can make safe loading decisions in minutes instead of hours.

What is a loadicator?A physical loading computer with monitor, keyboard, mouse and cabinet. The screen shows cargo holds and ballast and fuel tanks. Actual quantities and positions combine with approved ship-specific hydrostatic and ship-model data; an operator verifies inputs and results.Loadicator · a ship-specific loading workstationRepresentative console · quantities and positions drive the calculated conditionLOADED CONDITION · operator-entered caseH1H2H3H4H5Cargo holdsBallast tanksFuel tanksCalculated: strength · stability · draftsReview against approved ship-specific criteriaComputer cabinetActual inputsCargo / ballast / fuel quantities + positions from the current caseApproved ship modelHydrostatic + ship dataOperator verifies the input data, tank states and calculated loading condition. A decision aid—not autonomous safe-loading assurance or a universal equipment requirement.
Figure 1: What Is a Loadicator. A conveniently sited loading computer used on Ro-Ro vessels, bulk carriers, tankers and other cargo ships, giving the Master and loading officers a visual display of the ship's condition.

2. Purpose & Benefits

  • The main aim of the loading computer is to ensure that the vessel always departs the berth with adequate stability for the voyage — sufficient GM, adequate righting lever and an acceptable trim.
  • If this situation can be achieved quickly, costly delays can be eliminated and the safety criteria are complied with.
  • It allows the loading officers to test many loading options — how much to load in each hold/tank — and see immediately whether stability and strength limits are satisfied.
  • It reduces the risk of over-stressing the hull (excessive shear force or bending moment) and of sailing in an unsafe stability condition.

Changing Variables:

  • Ship's personnel can expect to become familiar with manipulating the changing variables alongside the fixed weight distribution throughout the ship.
  • This includes the amounts of bunkers, water and stores consumed during the voyage.
  • Stability data may change for arrival conditions — a ship loaded safely on departure may not be satisfactory on arrival if fuel and water have been consumed.

Departure vs arrival. The loadicator must be used to check both the departure and arrival conditions. A vessel that is safely loaded at the berth can still become unsafe (or over-stressed) by the time she reaches port, as consumables are used and weights shift.

3. Outputs Provided by the Loadicator

The loadicator programmes provide output in the form of:

  • Shear forces and bending moments affecting the vessel at its state of loading.
  • Cargo, ballast and fuel tonnage distributions.
  • A statement of loaded GM, sailing draughts and deadweight.
OutputWhat It Tells You
Shear force & bending momentLongitudinal strength — whether the hull is over-stressed along its length
Tonnage distributionsHow cargo, ballast and fuel are distributed between holds/tanks
Loaded GMInitial stability in the condition being assessed
Sailing draughtsForward and aft draught and trim for the voyage
DeadweightTotal weight of cargo, fuel, water, stores and constants

Surveyor asks: "What is a loadicator and what does it give you?" Answer with the three outputs: (1) shear forces & bending moments, (2) cargo/ballast/fuel tonnage distributions, and (3) loaded GM, sailing draughts and deadweight — plus that it ensures adequate departure stability and avoids costly delays.

Loadicator outputsA loading-output engineering plate reuses five-hold geometry and integrated shear and bending curves. Five 20 metre sections have cargo, ballast, fuel and lightship masses totalling 5000 tonnes. Weight minus uniform buoyancy integrates to shear force and bending moment with zero free-end values. GM, drafts and deadweight are labelled readout fields without invented hydrostatic numbers.Loadicator outputs · loading and hull-girder plateIllustrative 100 m beam case · SI force units · no allowable-limit envelope inventedH1H2H3H4H5emptyemptyWeight ↓Support ↑w, b [kN/m]wbq = w − b+196.2−294.3SF [kN]0BM [kN·m]00100 mFive equal 20 m sections · cargo in H1, H3 and H5w = 686.7 / 196.2 / 686.7 / 196.2 / 686.7 kN/m; b = 490.5 kN/mdSF/dx = w − b; dBM/dx = SF · SF and BM vanish at both free endsIllustrative peaks: SF ±3,924 kN · BM +65,400 kN·m (this sign convention)Mass distribution in the same case [t]Section (20 m)H1H2H3H4H5Cargo10000100001000Ballast8080808080Fuel2020202020Lightship300300300300300Total140040014004001400Σ mass = 5,000 t · buoyancy = 49,050 kN · g = 9.81 m/s²Other ship-specific readout fields (not numerically modelled here)GM [m], free-surface corrected · fore / aft drafts [m] · deadweight [t]Compare all applicable strength and stability criteria; SF / BM alone do not establish safety.
Figure 3: Loadicator Outputs. Shear force and bending moment along the ship's length, cargo/ballast/fuel tonnage distributions, and the loaded GM, sailing draughts and deadweight.

4. Use, Approval & Limitations

Approval & Correct Use:

  • The loading computer and its software must be approved and reflect the ship's actual hydrostatic and strength data.
  • The ship's fixed weight distribution (lightship, constants, known tank capacities) is built into the program.
  • The officer enters the changing variables — cargo in each hold/tank, ballast, bunkers, water, stores — and the computer evaluates the resulting condition.
  • Results are compared against the allowable limits in the stability booklet and loading manual.

Limitations:

  • The loadicator is a tool, not a substitute for the stability booklet; the Master remains responsible for the loading condition.
  • It must be kept updated with any change to the ship (additions, modifications, dry-docking results).
  • Garbage in — garbage out: entering wrong weights, tank soundings or densities gives misleading results.
  • Both departure and arrival conditions must be checked, and intermediate stages of loading where longitudinal strength (hogging/sagging and shear) may be critical.

Summary. Loadicator = loading computer that proves, before sailing, that the ship has adequate stability (GM), acceptable trim and draughts, and safe shear forces/bending moments for the departure and arrival conditions — quickly, so no costly delays arise.