Loading Computer
A loading computer is the class-approved onboard instrument that calculates a tanker's stability, trim, and hull girder bending moment and shear force for any loading condition before cargo operations start, not a general-purpose stability app.
What to check on a Loading Computer.
2 models from Honeywell in Loading Computer. Below: the full model list.
What a loading computer actually calculates
A loading computer takes the ship's hull form, tank arrangement and lightship data and, for any combination of cargo, ballast and consumables entered by the officer, works out draft, trim, GM and the bending moment and shear force at every hull section along the length. For a tanker this matters more than for most ship types: cargo is liquid, tanks can be slack, and a loading sequence that is fine at the end can put unacceptable stress on the hull partway through discharge. The computer checks the condition against the ship's approved limits, not against generic stability rules.
Legend
- tank sounding data
- LOADING COMPUTER
- bending moment / shear diagram
- draft & density input
- class-approved unit
- trim & stability result
Main components
Hull and tank data model
A ship-specific database of hydrostatic curves, tank capacities, centres of gravity and cross-curves of stability, built from the vessel's approved stability booklet and loading manual and locked so the crew cannot alter the underlying particulars.
Intact stability module
Calculates displacement, drafts fore and aft, trim, GM and compares the resulting righting-lever curve against the applicable intact stability criteria for the loading condition entered.
Read the full guide
Longitudinal strength module
Produces the still-water bending moment and shear force curve along the hull and checks it against the class-approved permissible limits at each frame, including during intermediate stages of loading or discharge, not just the final condition.
Damage stability module
Required on tankers above the applicable size threshold: checks residual stability after specified hull breaches, needed for compliance with MARPOL Annex I damage stability requirements.
Selection and approval
The instrument itself must be type-approved and then approved by class for the specific ship, since it is only as accurate as the hull data loaded into it. Owners choosing between systems weigh the calculation modules included, intact only or intact plus damage plus strength, ease of the loading sequence simulator, and whether the software integrates with the ship's tank gauging system for live figures during operations.
Regulations and class
SOLAS Ch. II-1 requires loading instruments capable of ascertaining intact and damage stability on tankers and bulk carriers of the relevant size, and the installed unit must carry class approval for the individual vessel after loading of the ship-specific hull data. Class surveys verify the approval certificate is current and that a test condition matches the approved loading manual within tolerance at each renewal.
Typical faults
- Hull data not updated after a conversion or steel renewal, so output no longer reflects the real ship
- Approval lapsed after a software update replaced the certified version, flagged at port state control
- Officers entering estimated tank soundings instead of actual gauge readings, so errors compound through the loading sequence
- Intermediate loading stages skipped in the check, only the final condition verified, so a hull stress peak is missed mid-sequence
What to look for in a supplier
- Class approval process included as part of the delivery, not left to the yard or owner to arrange separately
- Update path for hull data after any structural modification
- Interface to existing tank gauging and cargo control systems
- Training that covers intermediate-stage checking, not only the final loaded condition
Run the intermediate stages of a discharge sequence through the computer, not just start and finish: tanker hulls have failed from stress peaks that only existed for the twenty minutes in the middle of a cargo operation.
Models in this type.
The best-documented model of each manufacturer first, then the next — 2 of 2 models in Loading Computer. Every row links to full specifications, documents and service notes.
Manufacturers.
All 31 manufacturers with models of Loading Computer. Names with a manufacturer page open it; the others open a search across the full library.
All manufacturers in the libraryAlso in Tanker Cargo Systems.
The other equipment types in this category.
Write to us about this model — the answer comes by e-mail.
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Questions that come up with this equipment.
Is Loading Computer data free?
Yes. Every model page, every guide and every datasheet for this type is readable without an account. An account adds saved searches and requests, nothing is taken away.
My model is missing — what now?
Send us the nameplate. We identify it by hand, add it to the library, and if you need a part or a service, the request is already on our desk.
Can you source a Loading Computer part?
Yes. Tell us the manufacturer, the model and what you need — a person reads every request and replies by e-mail.