Container glossary
What is OOG cargo?
OOG (out of gauge) is cargo that extends beyond the outline of the container carrying it — taller, wider or longer than the frame. It travels on a flat rack or in an open top, and it is priced for the neighbouring slots the ship has to leave empty.
How an out-of-gauge load is accepted and stowed
Containers stack because every one has the same outline. Cargo that breaks the outline takes away the positions next to it or above it: nothing can be stacked on an over-height load, nothing can stand beside an over-wide one. The shipping line therefore treats each OOG booking as a separate case. It asks for the dimensions and weight of the piece, usually a drawing with lifting and lashing points, and decides whether and where on the vessel it can go before confirming.
The rate reflects the slots lost, on top of the special equipment itself. The cargo is then secured to the equipment — see lashing — and heavy pieces rest on timbers that spread the load across the floor.
Which equipment takes which overhang
An open top container handles height only. It keeps its walls, so the cargo must still pass a roof opening about 2.23 m wide; what rises above the top rail rides under the tarpaulin as over-height. A flat rack has no sides and no roof, so it takes over-width and over-height together, and over-length if the end walls fold down.
On the booking and the quotation the overhang is itemised: over-height, over-width on each side, over-length at each end, in centimetres beyond the frame. Cargo that stays within the frame on the same equipment is called in gauge (IG) and costs less, which is worth knowing when a piece is only just too big.
Measuring the machine and not the shipment
The usual mistake is giving the carrier the dimensions from the manufacturer’s data sheet. What matters is the piece as it will travel: on its skid or cradle, on the bedding timbers, with packaging and anything that projects. A few centimetres decide whether a load is in gauge or out of it, and whether one adjacent slot is lost or two.
When the piece arrives at the terminal larger than declared, the stowage planned for it no longer works. The result is a re-quote at best and a missed sailing at worst, with storage running while it is sorted out. The same care applies inland: rail clearances are tighter than road ones, so an out-of-gauge load needs a clearance check for every leg, not only for the ship.
Frequently asked questions
What does OOG stand for?
Out of gauge — cargo whose height, width or length exceeds the outline of the container it is loaded on. Its opposite is in gauge (IG), cargo that stays within the frame.
Can OOG cargo go in a normal container?
No — a closed dry container cannot carry anything that exceeds its inside dimensions or its door, which is 2.340 m wide and 2.280 m high (7 ft 8 in × 7 ft 6 in). Oversize pieces move on a flat rack or in an open top.
Why is OOG freight more expensive?
Because the ship loses the slots around the load: nothing can be stacked on or beside the overhang, and the line charges for that lost capacity. Special equipment and extra lashing add to it.