Once cargo stops fitting in a standard box, the job changes from booking to engineering.
01Reefer discipline
A refrigerated container maintains temperature; it does not reduce it. Cargo must be at its target temperature before stuffing. Loading warm produce into a reefer set to +2°C and expecting it to pull down is a claim waiting to be filed.
The controls that matter:
- Pre-trip inspection (PTI) — insist on a PTI certificate before stuffing. A unit that fails mid-voyage on a 30-day sailing is a total loss.
- Set point vs. supply vs. return air — the set point is what you asked for; supply air is what the unit delivers; return air reflects the cargo. Chilled cargo is controlled on supply air, frozen on return.
- Ventilation setting — respiring cargo like fruit and vegetables needs fresh air exchange; frozen cargo does not. Wrong setting, wrong outcome.
- Loading pattern — do not block the T-bar floor channels and do not load above the red load line. Air must circulate or the top-centre pallets arrive warm.
- Data logger — put an independent logger in the cargo, not just the container's own record. It is the evidence in a claim.
- Plug-in continuity — the gap between gate-out and plug-in at the terminal is where cold chains break. Confirm plug times at every transfer.
02Out-of-gauge cargo
When cargo exceeds container dimensions:
- Over-height — flat rack or open top. Over-height by sea has a stowage penalty because the slots above cannot be used.
- Over-width — flat rack, with the adjacent slots blocked. Charged accordingly.
- Over-length — flat racks coupled, or breakbulk.
OOG bookings need dimensions and weight confirmed to the centimetre and kilogram, plus lifting point details. The line quotes based on the slots your cargo sterilises, so an extra 10 cm of width can change the price step-wise, not gradually.
03Project cargo — the workflow
Project cargo is a transformer, a turbine, a pressure vessel, a complete production line. The freight rate is the small part.
- Technical dossier. Dimensions, weight, centre of gravity, lifting points, permissible sling angles, and any shock or tilt limits.
- Route survey. Physically drive the inland route. Bridge clearances, weight limits, turning radii, overhead cables, roadside furniture. Every constraint is a permit or a modification.
- Lifting plan. Crane capacity at the required radius, ground bearing pressure, rigging design, and a method statement. Signed by a qualified engineer.
- Permits. Oversize and overweight road permits, police escort where required, and utility coordination if cables must be lifted.
- Marine transport engineering. Stowage position, lashing and securing calculation approved by the carrier or a marine warranty surveyor.
- Insurance. Standard cargo cover is rarely adequate. Project cargo needs specific cover with the surveyor's approval built in.
- Timing. Night moves, tide windows for barge work, and holiday restrictions on oversize road movement.
Lead times are measured in months, not weeks. The first question on any project enquiry is not the rate — it is the date, the dimensions, and whether a route survey has been done.