Spotted: Tight Squeeze through Miraflores Locks

The Panama Canal Authority shared this photo of the China-flagged bulk carrier Yun Long Feng waiting for a lock chamber to fill so it can pass through the 101-year-old set of Miraflores Locks.

With a dead weight tonnage of 75,394 dwt, the 2012-built Yun Long Feng understandably falls into the category of the so-called Panamax vessels, that is to say its size was limited by the size of the Canal’s lock chambers, by the depth of water in the Canal, and by the height of the Bridge of the Americas.

The current Canal’s lock chambers are 110 ft (33.53 m) wide, 1,050 ft (320.04 m) long, and 41.2 ft (12.56 m) deep. The usable length of each lock chamber is 1,000 ft (304.8 m). The available water depth in the lock chambers varies, but the shallowest depth is at the south sill of the Pedro Miguel Locks and is 41.2 ft (12.56 m) at a Miraflores Lake level of 54 ft 6 in (16.61 m). The height of the Bridge of the Americas at Balboa is the limiting factor on a vessel’s overall height; the exact figure depends on the water level.

A Panamax cargo ship typically has a dwt of 65,000–80,000 tonnes, but its maximum cargo would be about 52,500 tonnes during a transit due to draft limitations in the Canal.

The Panama Canal is currently undergoing extensive expansion works, after which it will be able to accommodate the so-called New Panamax vessels: container ships with the cargo capacity of 13,000 TEU (currently boxships with up to 5,000 TEU capacity can fit through the locks), and other types of cargo ships with a dwt of up to 120,000 tonnes.