Safety
Loadicator / Loading Computer
The onboard loading computer that proves adequate stability, allowable stresses and draughts before the ship sails.
Key Principles at a Glance 6 points
- Most modern cargo ships are equipped with a loadicator or loading computer with appropriate software, usually a conveniently sited visual display for the Master and loading officers.
- It is used on Ro-Ro vessels, bulk carriers, tankers and other cargo ships.
- The main aim of the loading computer is to ensure that the vessel always departs the berth with adequate stability for the voyage; achieving this quickly eliminates costly delays and ensures safety criteria are complied with.
- Ship's personnel must become familiar with manipulating the changing variables (bunkers, water and stores consumed) alongside the fixed weight distribution throughout the ship, including arrival conditions where stability data may change.
- The loadicator provides output in the form of shear forces and bending moments affecting the vessel at its state of loading, cargo/ballast/fuel tonnage distributions, and a statement of loaded GM, sailing draughts and deadweight.
- It is a decision-support tool — the Master remains responsible for the loading condition, and the loading computer must reflect the ship's approved stability and strength limits.
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.
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.
- 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.
| Output | What It Tells You |
|---|---|
| Shear force & bending moment | Longitudinal strength — whether the hull is over-stressed along its length |
| Tonnage distributions | How cargo, ballast and fuel are distributed between holds/tanks |
| Loaded GM | Initial stability in the condition being assessed |
| Sailing draughts | Forward and aft draught and trim for the voyage |
| Deadweight | Total weight of cargo, fuel, water, stores and constants |
Surveyor Asks
Surveyors commonly ask: "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.
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 strength 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.