The Construction of the Panama Canal and the Current Repair Project

By Risa Farber

Throughout the 1800s, businessmen were tiring of the long and arduous journey to ship goods between the Atlantic and Pacific Oceans. The trip would take around two months by boat, traveling from the East Coast over 8,000 nautical miles all the way around the southernmost tip of South America by Cape Horn before traveling back up to the western coast of the U.S. The French attempted a solution to this problem, spearheaded by Ferdinand de Lesseps, the engineer behind the Suez Canal in Egypt. They began excavating a canal across the Isthmus of Panama in 1880, but went bankrupt and had to stop due to outbreaks of malaria and yellow fever that took approximately 20,000 lives. Twenty years later, in 1901, the Hay-Pauncefote Treaty gave the U.S. license to make a second attempt at building the canal, but after discussing terms with the Colombian Foreign Minister Tomas Herran, Congress decided the cost was too steep and declined the offer. President Theodore Roosevelt strategized a solution to this by supporting the ongoing fight for Panamanian independence from Colombia, in hopes that a new government would prove more profitable to the U.S. His wish came true, and a new treaty was signed, granting American access to a 10-mile-wide strip for the canal.

The Panama Canal is 40 miles long, from the Pacific to the Atlantic shoreline, taking ships from either direction approximately 10 hours to cross. Contrary to popular belief, the canal doesn’t actually run directly east-west across the isthmus (i.e., a narrow strip of land with water on either side), but actually starts in the north at Colon and runs directly due south before turning southeast towards Panama City and Balboa. It was built by creating dams on the Chagres River to create the Gatun and Alajela Lakes, digging the Gaillard Cut over the Continental Divide, and building locks along the way to lift and lower boats. Throughout all of the canal’s intricate twists and turns, various construction methods had to be invented from scratch or altered due to the canal’s unique properties. 

​One of the major features of any canal, but the Panama Canal in particular, is the lock mechanisms. A lock on a waterway is essentially an elevator for ships and boats. The vessels enter a concrete chamber in the course of the river with gates at either end. The chamber is then filled or emptied, depending on the direction traveled, by opening or closing two sluices set on hinges (a specific type of gate for containing water). The size and shape of the various openings determine the speed at which the volume of water is altered, to maximize speed but minimize turbulence to the ships. Originally, there were only six locks throughout the path, but in recent years, another six have been added. Only small boats can pass through the lock unassisted- larger vessels must be guided through with electric towing locomotives on cog tracks atop the walls to keep the ship centered. Additionally, there is a fender chain that is stretched between the two lock walls. If the ship is proceeding properly and stops when they are at the center of the lock, the chain is lowered, but if it is moving rapidly, the chain will remain to hold the boat in place until it stops. In the Panama Canal, ships enter the northern side at Colon and then are lifted up 85 feet by three locks to reach Gatun Lake before heading towards the Gaillard Cut. 

The Gaillard Cut was the location for the majority of the digging in the original construction. This is because Panama is situated right along the Continental Divide, a major mountain range that runs from Alaska down to Chile. This means that throughout the canal, enormous amounts of rock and earth needed to be dug up. In some places, the cut is up to 500 feet deep and 300 feet wide. To remove this much earth, holes were drilled and filled with explosives to detonate and loosen the rock and hard clay. The U.S. was known for its technological prowess at the time, and used this excavation opportunity to show off to the rest of the world. One machine they used was the steam shovel, an early version of a modern-day excavation machine. It was used to move large amounts of rock and was powered by steam, and was popular back in the U.S. with the construction of Route 66. 

Additionally, the U.S. used steam-powered “spreaders,” which were operated using compressed air. The machine had steel “wings” on each side that were raised and lowered to spread out dirt while moving forward. Workers also used track shifters, which were an early crane-like machine that could hoist a whole 9-ft segment of railroad track and swing it around. The French, on the other hand, only knew of the steam shovel, and a much less powerful version at that.

When digging up the Gaillard Cut, earth slides were a major concern. The first happened in October 1907, when 500,000 cubic yards of material moved into the Cut following heavy rainfall. This type of slide is considered a normal, or gravity, slide and is caused when a layer of porous material rests on a sloping surface of a harder material (such as rock). Rainwater saturates the porous material, forming a slippery zone and causing the entire top layer to slide down. Other types of slides are structural breaks and deformation slides. This is caused by a combination of unstable geological conditions, slope steepness, height, and blasting effects. At the canal, excavation had removed the lateral support (horizontal forces that prevent collapse or movement) from the high banks in the deepest portions of the Cut. Thus, the slopes, unable to handle the weight, sheared and settled, forcing the underlayer of poor quality cork to be crushed. 

Over the years, the U.S. was able to overcome these obstacles and use its groundbreaking (literally) machines to complete the Panama Canal in 1913, linking the world’s two largest oceans. Throughout the years, improvements have been added, but the engineering behind the original design still stands the test of time.