Sea cargo reference
Panamax
Drawn to the old Panama locks. The notes below cover the cargo, the way the hull is arranged, and the limit that puts a ship in this class.
- Typical deadweight
- Typically about 65,000-80,000 DWT
- Length overall
- Maximum 294.13 m
- Beam
- Maximum 32.31 m; typically about 32.26 m
- Draft
- Maximum 12.04 m in tropical fresh water
- The limit that names it
- The original Panama Canal locks
- Ship's gear
- Usually gearless
- Typical draught
- About 14.1 m at full load, above the canal transit limit
- Cargo holds
- 7
Names such as Handysize, Supramax and Capesize are market habits, not a written standard. Brokers, exchanges and owners do not all use the same deadweight band. Canal and berth limits below are published figures and stay fixed. The deadweight ranges are a guide.
Panamax bulkers
This class follows the original Panama Canal locks. For most of the twentieth century those locks set the largest ship that could pass between the Atlantic and the Pacific without rounding South America.
The limits are exact: 294.13 metres length overall, 32.31 metres beam and 12.04 metres draft in tropical fresh water. Ships were built right up to those figures, and the beam limit in particular shaped the hull of a whole generation of bulk carriers.
The larger Neopanamax locks opened in 2016 and eased the limit a great deal. Panamax is still a distinct size, and it is still heavily traded on its own.
Cargo on board
How the hull is arranged
- One deck, with large holds closed by steel hatch covers that roll or fold aside for grabs and conveyors.
- Ballast sits in the double bottom and in the topside and hopper tanks. Those tanks also shape the hold so the cargo trims itself as it settles.
- Corrugated bulkheads stand between the holds. They take the push of a dense cargo without extra frames inside the space.
- Engine and accommodation sit aft, so the forward length stays free for cargo.
- Geared ships carry deck cranes or derricks between the hatches and can work where the port has no gear of its own.
Why this trade uses it
- A dry commodity moves with no bags, boxes or lashings, which keeps the cost per tonne low.
- Where the shore gear is good, grabs, conveyors and shiploaders shift thousands of tonnes an hour.
- A geared ship can call at ports that have no cranes.
- Holds can take several parcels of different commodities on one voyage.
Settle these points before you fix
- Iron ore and other dense cargoes load the hull hard. The loading order is strict, so the ship is not overstressed.
- Some concentrates and fines can turn liquid. They have to be checked against the transportable moisture limit before loading.
- Draft and air draft decide which berths and waterways the ship can use. Both shift with the season and the fresh-water allowance.