About 42 percent of the work on the massive new locks has been completed, and it's by far the most costly and complicated part of the $5.25bn project to retrofit the nearly century-old canal with larger locks to lift and lower ships on both the Atlantic and Pacific sides of the isthmus.
The old locks will still be in service, but the new ones will allow the canal to handle so-called post-Panamax ships. The length of three football fields, such vessels are too long, too heavy and too wide to fit through the existing locks.
Most of the rest of the canal renovation, such as deepening and widening channels along the original route of the canal and construction of new access channels, is finished or nearly so. In early March, a milestone was reached when dredging of Culebra Cut, the narrowest part of the canal that straddles the Continental Divide, was completed.
