Panamax container ship

A Panamax container ship is sized to the original Panama Canal locks: 294.1 m length overall, 32.3 m beam, and about 12 m draft, which capped capacity near 5,000 TEU. The 32.3 m beam, set by the old 33.5 m lock chambers, was the binding constraint; it limited on-deck stowage to 13 container rows across and forced narrow, deep hulls. After the Neopanamax locks opened in 2016 (366 m by 49 m by 15.2 m), the old Panamax box ship lost its reason to exist and many were scrapped or cascaded to regional trades. The class now reads as a historical tier between feeders and the post-Panamax and Neopanamax ships that replaced it.