When John F. Stevens took over as chief engineer in 1905, he zeroed in on the two problems that had defied the French and ended their venture in bankruptcy—how to excavate through the mountainous terrain of Culebra Pass and how to dam the raging Chagres River. Heavy rains that shortened the work schedule and ever-present mud slides had turned the French method into a two-steps-forward-one-step-back proposition. Helped by advances in technology, the Americans were able to stay ahead of nature and devise an integrated solution to both problems.
Excavation was expedited simply by being able to use the much larger steam shovels that had been developed in the years since the French effort. Working from both sides towards the middle, twenty-three of the new machines were assigned to work on the Culebra cut, measuring 300 feet wide at the bottom and 1,800 feet at the top. Each shovel had the capacity to fill a rail car in just eight minutes, operated by crews of ten who lived on-site. Of the 300 million cubic yards of material excavated to complete the canal, a third came from the Culebra cut.
The canal design consisted of a series of locks, three at Gatun on the Caribbean, north of Culebra, and two on the Pacific side, south of the cut, separated by a 163 square-mile lake. The building of the five sets of 1,000-ft long 110-ft wide locks was the final ambitious undertaking of the canal's construction. Work on the Gatun locks began in 1909 and the Pacific set a year later. The locks were designed as pairs, so vessels could travel in both directions at once, separated by a sixty-ft thick wall. The inland Pedro Miguel locks were finished first, in 1911, then the Miraflores locks at the Pacific entrance in May of 1913, the same month the Culebra cut was completed, and the Gatun locks the following September.
To prevent the waters of Gatun Lake from escaping into the Culebra cut, a temporary earthen dam, called the Gamboa Dike had been put in place. The dike was gradually eliminated using dynamite charges, with the final charge symbolically ignited by the push of a button by President Woodrow Wilson on October 10, 1913. As the grand opening neared, workers scrambled to clear one last mud slide from the Culebra cut that threatened the upcoming media event.
By the time the big day finally arrived, the world's attention was focused elsewhere. As the water gradually filled the canal during the final three weeks in preparation for the August 15, 1914 opening ceremonies, Germany, Austria-Hungary, Russia, France, Belgium and Great Britain all entered World War I. The impressive cavalcade of a hundred U.S. Navy warships passing through the canal was scrapped. The opening of the canal, though noted in the press, did not make the front page.
