Insights · Data · Biggest container ships
The largest container ship ever built carries enough boxes to stretch from London to Birmingham. This is the record-holder, the unit that measures it, and why the giants have stopped getting bigger.
Ask which is the biggest ship in the world and the honest answer is: it depends what you mean by big. Cruise ships win on gross tonnage. Crude tankers win on deadweight. But when people picture a floating wall of steel boxes nine storeys high, they mean a container ship — and container ships are ranked by neither tonnage nor deadweight, but by how many boxes they carry. On that measure there is a clear champion, and it has a name: MSC Irina.
The standard measure of a container ship's capacity is the TEU — the twenty-foot equivalent unit. One TEU is one standard twenty-foot shipping container; a forty-foot box counts as two. It is a unit of slots, not weight, and it is the only sensible way to compare boxships, because their whole purpose is to move as many containers as physically possible on a single voyage.
This is why container ships are not ranked the way other vessels are. Gross tonnage measures enclosed volume and deadweight measures cargo weight, and both matter for the paperwork, but neither tells you the thing a liner operator actually cares about: how many boxes fit on board. A ship can be heavy without being capacious, or huge in volume without carrying many containers. TEU cuts straight to the point — and on TEU, one ship currently stands above the rest.
MSC Irina is the largest container ship ever built, with a capacity of 24,346 TEU as of 2026. She was delivered in 2023 from the yard of Jiangsu Yangzi-Xinfu Shipbuilding in China, and she is operated by MSC — the Mediterranean Shipping Company, the world's largest container line by fleet capacity.
The headline dimensions tell you why she sits at the top:
| Specification | MSC Irina |
|---|---|
| Capacity | 24,346 TEU |
| Length overall | 399.99 m |
| Beam | 61.3 m |
| Delivered | 2023 |
| Builder | Jiangsu Yangzi-Xinfu |
| Operator | MSC |
That length is no accident: at 399.99 m she stops a single centimetre short of 400 m, a figure that recurs across the whole top tier of the container fleet. She is also a ship built for the post-2020 emissions reality. MSC Irina carries a suite of energy-saving features — a small bulbous bow, large-diameter propellers, energy-saving ducts, an air-lubrication system that blows a carpet of bubbles under the hull to cut friction, and shaft generators that reclaim power from the main engine. Twenty years ago a ship this size would simply have burned more fuel; today the engineering effort goes into moving the same wall of boxes for less.
It is tempting to assume the giants will keep growing, but they have largely stopped. The reason is not shipbuilding — yards could weld a longer hull — it is the infrastructure the ship has to fit through. The 24,000-TEU class is what the industry calls ultra large container vessels (ULCVs), sometimes megamax, and they are bounded by two stubborn numbers: a length of about 400 m and a beam of about 61 m.
Those limits are set by the physical world the ship trades in. A 61-metre beam is far too wide for the old Panama Canal locks, so these vessels are designed for the Asia–Europe route through the Suez Canal instead. The length and draught are tuned to the handful of deep-water hub ports — the cranes that can reach across more than twenty container rows, the berths long enough to take a 400 m hull, the channels dredged deep enough to float it fully laden. Build a ship bigger than that and most of the world's terminals simply cannot handle it.
The biggest boxships are not limited by what shipyards can build. They are limited by the width of a canal and the reach of a crane. The ULCV ceiling, c. 2026
The practical effect is that the record is held by a hair. A cluster of sister and near-sister ships — the rest of the MSC megamax series, along with earlier 24,000-TEU-class vessels from the likes of OOCL, HMM and the Ever-class — sit just behind MSC Irina in the 23,000–24,000 TEU band. The difference between first place and tenth is a few hundred slots, not a different category of ship. The age of doubling capacity every few years is over; the giants have converged on a single shape.
If you want to see where any of these ships sits, the fastest route is to open its file. Search the container fleet in the Marifest registry and you can pull up MSC Irina's record directly — her IMO number, flag, registered owner and operator, builder and the headline dimensions that put her at the top of the list. You can also filter the registry to cargo vessels to see the ULCVs ranked alongside the smaller feeders and panamaxes that move the same boxes across shorter legs.
Every vessel file is keyed to its permanent IMO number, so a rename or a change of charter never breaks the trail — useful when a liner reshuffles a megamax between its alliances. And if the alphabet soup of TEU, ULCV, GT and DWT starts to blur, the Marifest glossary spells out each term in plain English. The biggest ship in the world is, in the end, just a row in a database — one you can open for yourself.
How Marifest tracks the fleet
Marifest holds the container fleet as an open, searchable registry — every boxship keyed to its IMO number, ranked by capacity, and cross-checked against the sanctions lists. Whether you want the record-holder or a coastal feeder, it is one search away.
Filter to cargo vessels and the ultra large container ships sort to the top — MSC Irina at 24,346 TEU and the rest of the 24,000-TEU class right behind her.
Open any boxship and read its specs, flag, registered owner and operator, builder and year — the dimensions that decide whether it is a megamax or a panamax.
Each ship is keyed to its permanent IMO number, so a charter swap between alliances or a rename never loses the record.
Container ships are matched against OFAC, EU, UN and UK sanctions lists by IMO number, so the compliance verdict travels with the hull.