lpetrich wrote:The New Panamax clearance is still not as wide or as deep as the Chinamax clearance. Also, the Panama Canal has capacity problems. From Wikipedia's Panamax article, "Because the largest ships traveling in opposite directions cannot pass safely within the Culebra Cut, the canal effectively operates an alternating one-way system for these ships." Though that needs a "Citation needed", other sources agree.
The Culebra Cut is a channel dug through the mountains of central Panama. Digging it was a massive effort and a great engineering feat in its day.
There was a study a while back, not sure what thread it was in, that China is considering using a rock cutting dredge to widen and deepen the Culebra Cut to make it safe for large vessels to pass in both directions.
There is also talk every few years about upgrading the Saint Lawrence Seaway to at least old Panamax standards so that ocean going Container ships of Panamax size could travle all the way interior to Chicago, Illinois.