Home / Logistics Knowledge / Container Types & Sizes / 20ft Open Top Container (20OT)
The 20OT has no fixed steel roof — removable roof bows and a waterproof tarpaulin close the top. It solves loading from above: over-height cargo, or cargo that cannot enter through the end door, is lowered in by crane.
The 20OT has no fixed steel roof; instead, removable roof bows plus a waterproof tarpaulin close the top. It solves one problem — loading from above: over-height cargo, or cargo that cannot be pushed through the end door, is lowered straight in by crane.
The box keeps full side and end walls (so structural strength is intact); only the top opens. After loading, the tarpaulin goes on and is lashed around the body against rain. For a trading company, when a piece is a little taller than the door or must be craned in, an open top is a cheaper fix than dismantling or a flat rack.
Full name: 20-foot Open Top Container
A single piece must be no longer than the 5,898 mm internal length and no wider than 2,352 mm; height may slightly exceed the top rail (about 2.348 m), but the overhang must be covered by the tarpaulin and secured against rain. Much taller cargo needs a flat rack or breakbulk.
| Dimension | mm | cm | m | ft & in | in |
|---|---|---|---|---|---|
| Length | 5898 | 589.8 | 5.898 | 19 ft 4.2 in | 232.2 |
| Width | 2352 | 235.2 | 2.352 | 7 ft 8.6 in | 92.6 |
| Height | 2348 | 234.8 | 2.348 | 7 ft 8.4 in | 92.4 |
| Door opening width | 2340 | 234.0 | 2.340 | 7 ft 8.1 in | 92.1 |
| Door opening height | 2280 | 228.0 | 2.280 | 7 ft 5.8 in | 89.8 |
| Dimension | mm | cm | m | ft & in | in |
|---|---|---|---|---|---|
| Length | 6058 | 605.8 | 6.058 | 19 ft 10.5 in | 238.5 |
| Width | 2438 | 243.8 | 2.438 | 7 ft 12.0 in | 96.0 |
| Height | 2591 | 259.1 | 2.591 | 8 ft 6.0 in | 102.0 |
| Door opening width | 2340 | 234.0 | 2.340 | 7 ft 8.1 in | 92.1 |
| Door opening height | 2280 | 228.0 | 2.280 | 7 ft 5.8 in | 89.8 |
| Item | Tonnes (t) | Kilograms (kg) | Pounds (lb) |
|---|---|---|---|
| Tare weight (empty) | 2.20 – 2.40 | 2,200 – 2,400 | 4,850 – 5,291 |
| Maximum payload (net cargo) | 28.22 | 28,220 | 62,214 |
| Maximum gross weight (box + cargo) | 30.48 | 30,480 | 67,197 |
New (one-trip) 20OT containers have just left the factory or carried a single load: flat panels, tight door seals and no corrosion, which makes them the right choice for food, precision goods and long-term leasing. Used (multi-trip) 20OT boxes have years of ocean service behind them and may show dents, light rust and worn flooring, but a structurally sound unit that passes a cargo-worthy survey still ships perfectly normally.
On an open-top the consumables are the tarpaulin, the roof bows and the roof coaming, and they are often the first things to fail. Confirm the tarp is intact and the correct size, and check that the roof bow sockets are not distorted before you plan a crane lift.
For a 20OT, most exporters simply take the carrier’s “cargo worthy” unit, because the shipping line is responsible for the box being fit for carriage at the moment it is picked up. If you buy your own container instead, pricing is graded by age and condition: CW (cargo worthy), WWT (wind and water tight) and AS-IS (sold as seen).
Open tops are scarcer than dry boxes: new / one-trip units about USD 4,000–7,000.
Cargo-worthy used units about USD 2,000–4,500; supply is limited — confirm live.
Maersk, MSC, CMA CGM, COSCO, OOCL, Hapag-Lloyd, ONE and Evergreen all build to the same ISO standards, so the external dimensions of a 20OT match the standard exactly and the box can be stacked and interchanged on board and on the chassis without adaptation.
Across carriers, the practical differences for a 20OT are in box age and condition (new units are assigned to the mainline services), the builder (CIMC, Singamas, CXIC, Maersk Container Industry and others), small variations in the tare and payload figures stamped on the plate, and the configuration of special equipment — reefer unit brand, tarpaulin type on an open-top, folding versus fixed end walls on a flat-rack. Mention heavy, over-height or specialised cargo at booking so the carrier allocates the right unit.
Open-top availability depends on the trade: few lines carry them on feeder services, so book the special equipment first and the sailing second.
A 20OT holds about the same 32 CBM as a 20GP. Slightly over-height equipment, crane-loaded heavy cargo, bulk grain, scrap metal, logs and long pipes — anything easier to drop in from above — suit it best.
For heavy cargo in an open top, drop the pieces by crane from above and set them on dunnage to spread the pressure; spread the load evenly and avoid concentrating it mid-floor.
After top-loading, cover with the tarpaulin and lash it around the body (watertight and to stop overhang). Inside, fix large pieces to the floor lashing rings with timber and wire rope so they cannot shift during lift or voyage.
The 20OT suits over-height and crane-loaded cargo: machinery, motors, steel, scrap metal, bulk grain and feed, logs, glass and large moulds.
For bulk granulated cargo (grain, ore sand) keep the tarpaulin rain-tight, and note the floor and walls load differently — never load bulk above the top rail. For over-height pieces confirm the destination has the crane gear and the over-dimension permits.
An electric-motor order to Southeast Asia, 10 cm taller than the door, is lowered into a 20OT from the top and the tarpaulin lashed before sailing. A standard box would have jammed at the door.
External dimensions are 6,058 x 2,438 x 2,591 mm, the same as a dry 20ft. Internal dimensions are about 5,898 x 2,352 x 2,348 mm. The door opening is 2,340 mm wide by 2,280 mm high, and cargo can also be craned in through the open roof.
Nominal volume is 32.5 CBM against 33.2 CBM for a dry box. The difference comes from the heavier roof structure; usable volume is about 27-29 CBM.
Tare weight is about 2,200-2,400 kg, slightly more than a dry box. Maximum payload is about 28,220 kg and maximum gross mass 30,480 kg.
Cargo is lifted in from above by crane, or driven in through the door by forklift if it fits. The removable roof bows and the tarpaulin are refitted and secured before the box leaves for the port, and the same process reverses at destination.
No. The tarpaulin keeps rain and spray out, but the unit is not classed as watertight. Cargo that must stay fully dry needs shrink wrap, crating or a lined tarp, and moisture-sensitive goods should never rely on the roof cover alone.
When the cargo is taller than the 2,280 mm door but no wider or longer than the standard box: machinery on a skid, steel coils, pipes, granite slabs, timber bundles or over-height crates. If the cargo is also wider than the internal 2,352 mm, a flat-rack is the right unit.
An open-top has side walls and end doors and opens only at the roof, so it protects cargo from the sides. A flat-rack has no sides at all, so it takes cargo that is wider or longer than the box footprint but leaves it exposed. Over-height cargo within the footprint goes in an open-top; out-of-gauge cargo goes on a flat-rack.
Yes. The equipment is scarce, the tarpaulin and roof bows add handling, and any cargo above the top rail attracts out-of-gauge approval and possibly special stowage charges.
Out of Gauge: cargo that exceeds the standard external dimensions of the container. Carriers have to approve it, it is usually stowed on deck or in the top tier, and it is charged for the space it blocks rather than by weight alone.
Yes. The carrier normally requires a securing plan, and heavy or over-height pieces often need a surveyor's certificate. Lash to the floor rings and corner castings, never to the tarpaulin or the roof bows, and photograph the secured cargo before the tarp goes on.
Loaded open-tops are usually stowed on deck or in the top tier, because the tarpaulin roof cannot support another container. Empty units can be nested, and some designs allow limited stacking.
New and one-trip units run about USD 4,000-7,000 and cargo-worthy used units about USD 2,000-4,500. Supply is much thinner than for dry boxes, so confirm availability with a live offer.
Tall machinery, steel coils, pipes, glass racks, over-height crates, transformers and any cargo that fits the floor but not the door. It is the standard unit for heavy over-height pieces that do not need a flat-rack.
22U1: 22 identifies a 20-foot container, U an open-top and 1 a door opening at one end. The 40ft equivalent is 42U1.
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