What is OOG cargo?
OOG (out-of-gauge) cargo is any piece that does not fit inside a standard closed container, because it is wider, higher or longer than the box or its door opening. It travels on an open top or a flat rack container or, when no container takes it, as breakbulk: lifted piece by piece into a ship's hold or onto its deck.
Size is only half of it. A piece that fits a flat rack by its dimensions can still be too heavy for one, and a heavy piece changes the equipment, the vessel and the price. On the Indian road leg the same piece is often ODC, over-dimensional cargo, with its own trailer and permit questions.
Which equipment options are there?
Work from the simplest option upwards and stop at the first one that takes the piece:
- Closed box (20' GP, 40' GP, 40' HC). The piece must pass through the door, about 2.34 m wide and 2.28 m high (2.58 m on a high cube), fit the inside length and stay within the payload.
- Open top (20' OT, 40' OT). No fixed roof; loaded from above by crane. It takes cargo too tall for a closed box, but the width still has to fit inside the box, about 2.34 m.
- Flat rack (20' FR, 40' FR). A floor and end walls, with no sides or roof. It takes pieces too wide or too tall for anything else, loaded from the side or from above.
- Breakbulk. When no container takes the piece, because of its length, width, height or weight, it ships uncontainerised on a breakbulk or multipurpose vessel, usually priced per freight ton.
What are the indicative limits?
These are the typical values Moviqo's cargo check uses. Every line publishes its own and boxes of the same type differ, so they are a first check before you ask, not a booking.
| Equipment | Length up to | Width up to | Height up to | Payload |
|---|---|---|---|---|
| 20' GP | 5.89 m | 2.34 m (door) | 2.28 m (door) | 28 t |
| 40' GP | 12.03 m | 2.34 m (door) | 2.28 m (door) | 26.5 t |
| 40' HC | 12.03 m | 2.34 m (door) | 2.58 m (door) | 26.5 t |
| 20' open top | 5.89 m | 2.34 m | about 4.0 m (OH above 2.35 m) | 28 t |
| 40' open top | 12.03 m | 2.34 m | about 4.0 m (OH above 2.35 m) | 26.5 t |
| 20' flat rack | 5.60 m | about 4.3 m (OW beyond 2.438 m) | about 4.0 m (OH above 2.23 m) | 31 t |
| 40' flat rack | 11.65 m | about 4.3 m (OW beyond 2.438 m) | about 4.0 m (OH above 1.95 m) | 40 t |
Indicative only: confirm with the line. A line may accept more on a particular box or service, or less on an older one. Over-dimension also costs space on the ship, so lines price every OOG unit individually.
How do you decide, step by step?
- Take each piece's length, width and height in metres and its gross weight. Put the longer of the two horizontal sides as the length; the height stays as the piece stands.
- Try the closed boxes in order: 20' GP, 40' GP, 40' HC. The piece must be within the door width and height, the inside length and the payload.
- If only the height is too much and the piece is no wider than 2.34 m, try an open top: height up to about 4.0 m, with over-height counted above 2.35 m.
- If it is wider than 2.34 m, try a flat rack: up to about 4.3 m wide and 4.0 m high, and 5.60 m long and 31 t on a 20', or 11.65 m and 40 t on a 40'.
- If no flat rack takes it, it is breakbulk. Write down why: weight, length, width or height.
- Mark any piece of 40 t or more as heavy lift, whatever it ships on.
How are over-width and over-height measured?
Over-width (OW) is measured on each side beyond a container's outside width of 2.438 m: OW per side = (cargo width − 2.438) ÷ 2. A piece 3.60 m wide is (3.60 − 2.438) ÷ 2 = 0.58 m over, so OW 58 cm on each side.
Over-height (OH) is measured above the inside height the box is built for: about 2.35 m on an open top, 2.23 m on a 20' flat rack and 1.95 m on a 40' flat rack. A piece 3.40 m high on a 40' flat rack is 3.40 − 1.95 = 1.45 m over: OH 145 cm.
Both matter for the price. An over-width unit blocks the slots beside it and an over-height unit the slot above it, and lines charge for those lost slots.
Worked examples
Six pieces run through the steps above, the way Moviqo's cargo check does them.
| Piece | Size and weight | Indicative fit | Why |
|---|---|---|---|
| 1 · Generator set | 5.20 × 2.20 × 2.40 m, 9,500 kg | 40' HC | 2.40 m is too high for a 20' GP door (2.28 m) but within a 40' HC's 2.58 m. |
| 2 · Hydraulic press | 5.50 × 2.25 × 3.10 m, 18,000 kg | 20' OT, OH 75 cm | Too high for any closed box, narrow enough for an open top: 3.10 − 2.35 = 0.75 m. |
| 3 · Skid | 5.00 × 3.00 × 2.00 m, 20,000 kg | 20' FR, OW 28 cm per side | Too wide for an open top; (3.00 − 2.438) ÷ 2 = 0.28 m; 2.00 m is under 2.23 m, so no over-height. |
| 4 · Boiler drum | 9.80 × 3.60 × 3.40 m, 28,000 kg | 40' FR, OW 58 cm per side, OH 145 cm | Too long for a 20' flat rack; within a 40' flat rack's 11.65 m and 40 t. |
| 5 · Press bed | 6.20 × 2.40 × 1.60 m, 42,000 kg | Breakbulk, heavy lift | 2.40 m rules out closed boxes and open tops; 42 t is over a 40' flat rack's 40 t. |
| 6 · Reactor | 14.60 × 4.10 × 4.25 m, 96,000 kg | Breakbulk, heavy lift | Over the payload, longer than 11.65 m and higher than 4.0 m. |
Example 5 is the one to watch. By size it fits a 40' flat rack easily; only the weight moves it to breakbulk. Some lines run flat racks rated for more than 40 t, so ask before you rule one out, and price breakbulk alongside.
Example 1 shows the opposite trap: a piece only 5.20 m long still needs a 40-foot box, because the high cube is the only closed box tall enough for it.
What should you send the line for an OOG quote?
- Length, width and height of every piece, with the unit stated, and its gross weight
- A drawing showing the centre of gravity and the lifting and lashing points
- Photos of the cargo and its packing, skids or saddles
- The commodity, POL and POD, and the cargo ready date
- Whether it can be stacked on, and whether it is hazardous (with the UN number and IMO class)
- For the road legs: the pickup and delivery sites and how the piece will be loaded and unloaded
The more of this the first mail carries, the fewer rounds of questions before a firm rate.
When is breakbulk the better choice?
Even when a flat rack fits, breakbulk can be cheaper or simpler: several large pieces moving on one voyage, a piece that would need two flat racks side by side, or OOG surcharges and lost slots that add up to more than a breakbulk rate per freight ton. Ask for both and compare them per piece, including the port handling at both ends.
For the freight ton side of that comparison, see Freight tons and W/M, explained. For the terms used here, see the glossary.