Container ships are cellular ships: inside the holds, cell guides restrain containers vertically so no lashing is needed, while boxes on the hatch covers are secured with twistlocks, lashing rods and turnbuckles. Every position is expressed as a bay–row–tier code, and data exchange with terminals and lines runs on EDI messages such as BAPLIE and MOVINS.
In Indonesia the domestic container fleet is dominated by small to mid-size feeders on multi-port inter-island rotations. Many are geared, using ship cranes because not every port has gantry cranes. This makes POD sequence, restows and crane time cost drivers just as important as the number of TEU loaded.
In stability terms, container ships tend to have a high KG because deck cargo can reach five tiers or more. The planner must keep GM above the minimum, trim reasonable, bridge visibility in line with SOLAS V/22, and shear force and bending moment within limits, while respecting stack weight limits from the ship’s lashing data.
Typical sizes & characteristics
| Parameter | Typical range |
|---|---|
| Size classes (generic) | Feeder < ~3,000 TEU; old Panamax ~3,000–5,100 TEU; Neo-Panamax ~10,000–15,000 TEU; ULCV > ~15,000 TEU |
| Typical domestic ship | Often ~100–1,800 TEU, some geared with ship cranes |
| Position system | Odd bays 20 ft, even bays 40 ft; rows from centreline (even to port, odd to starboard); hold tiers 02, 04…, deck 82, 84… |
| Hatch covers | Mostly lift-away pontoons; a few hatchless designs |
| Reefers | Plugs usually 440 V three-phase; plug count and generator power cap reefer intake |
| Stack weight limits | Per bay/row for 20 and 40 ft, separately for hold and deck (ship data) |
| Typical draft | Feeders ~6–9 m; large mainliners up to ~16 m |
Typical ranges for the vessel class, not data for any specific ship. For planning, use your vessel’s stability booklet and capacity plan.
Cargo spaces & how they are modelled
Cellular holds
Hold slots are bounded by cell guides and a maximum tier height. Each slot is modelled with its allowed sizes (20/40/45 ft), high-cube height limit and stack weight per row.
Deck on hatch covers
Deck cargo is secured with lashings per the Cargo Securing Manual. Tier count is limited by stack weight, lashing forces and bridge line of sight.
Reefer slots with plugs
Only powered positions accept running reefers. The vessel model records plug locations and counts per bay.
OOG and special positions
Out-of-gauge flat racks and open tops occupy adjacent or overhead slots. Positions allowed to take DG are flagged per bay.
Ballast and fuel tanks
Tank contents drive displacement, KG and free surface. Tank conditions per port are part of the stability calculation.
General stowage rules
POD sequence
Boxes for the next port must not sit under boxes for a later port. Breaking the sequence means restows and extra crane time.
Heavy low, light high
Heavy boxes go in lower tiers and in the holds to keep KG down. Stack weight limits per row still apply, including mixed 20 and 40 ft stacks.
Slot compatibility
20 ft in a 40 ft slot only where the ship allows it, 45 ft only in positions designed for it, and high-cube height checked against tier or hatch cover limits.
Stability and visibility
GM, trim, heel, SF/BM and bridge line of sight are checked for every departure and arrival condition, not only at the end of the bay plan.
VGM and dangerous goods
Only boxes with a VGM under SOLAS VI/2 may be loaded. DG boxes follow segregation and stowage categories from the IMDG Code edition in force.
Common mistakes & risks
- Actual weights far from declared weights, throwing stack weights and GM off.
- Deck stacks too tall and heavy, pushing lashing forces beyond capacity.
- Chain restows because the POD order ignored later ports.
- Reefers placed in slots without plugs or beyond the ship’s power capacity.
- A very stiff ship (large GM) whose violent rolling overloads the lashings.
- DG boxes stowed near heat sources or without adequate segregation.
Frequently asked questions
What is the difference between odd and even bays?
Odd bays mark 20 ft container positions, while even bays are used for 40 ft boxes that occupy two consecutive 20 ft bays. This convention is used in BAPLIE and in most bay plans.
Why is too much GM also dangerous?
A large GM gives a short roll period and high accelerations. Those accelerations load twistlocks and lashing rods, so deck stacks can collapse even when intact stability criteria are met.
Can STOWAGE.ID stability results replace the ship’s loading computer?
No. Engine results are shore-side planning and decision support. The class-approved onboard loading computer and the stability booklet remain the official reference before departure.
When is the Container Stowage Planner available?
The container module is the second wave after Barge, LCT and General Cargo, and its features are rolling out in stages, including BAPLIE and MOVINS import.
Shore-side planning & decision support. The class-approved onboard loading computer remains the official reference.