Culebra Cut

Listen first. Somewhere below, a ship's engine hums low and steady, and the sound carries off the rock walls on either side. The air is thick and warm. It smells of wet earth and green leaves. Out on the water, a vessel taller than an apartment block slides past at a walking pace. You are standing at the narrowest part of the Panama Canal. This is the stretch that cost more effort than any other.

This is the Culebra Cut. The name means snake in Spanish, and the channel does bend gently through the hills. What makes this place special is simple to say and hard to picture. Here, engineers cut straight through the Continental Divide, the spine of high ground that separates the waters flowing toward the Atlantic from those flowing toward the Pacific. Every ship crossing Panama passes through this gap in the mountains. Before the canal, there was no gap at all.

The French came first. In the early 1880s, a company led by Ferdinand de Lesseps, the man behind the Suez Canal, began digging here. In Egypt he had worked in flat, dry sand. Panama was the opposite. The rain was heavy, the soil was soft and unstable, and disease moved fast through the work camps. Yellow fever and malaria killed thousands of workers. By the end of the decade, the French effort had collapsed into bankruptcy and scandal.

The United States took over the project in 1904. The American engineers made one key decision. They would not try to dig a channel down to sea level. Instead, they built locks to lift ships up and over the land, and they dammed the Chagres River to create a huge lake. That choice reduced the digging. But here, at the Divide, there was no way around it. The hills still had to come down.

The work in this cut became one of the largest excavations of its time. Workers drilled holes in the rock and packed them with dynamite. Steam shovels then scooped the broken stone into railway cars. A network of tracks ran along terraces on the slopes, and trains carried the spoil away all day. Much of that rock and soil did not go to waste. It helped build the dams and breakwaters elsewhere along the canal.

Here is something many visitors do not know. The biggest enemy in the Culebra Cut was not the hard rock. It was the soft rock. Layers of clay and weak shale sat on top of harder material, and in the heavy rain they slid. Landslides poured back into the channel again and again. One famous slide on the eastern bank was called Cucaracha, the cockroach. Workers would clear a section, and weeks later the hillside would move in and fill it again.

The man in charge of this section was David Gaillard, an engineer from the United States Army. He spent years fighting the slides, the heat, and the deadlines. The pressure was enormous. He became ill and died in 1913, before the canal opened to ships. After his death, the channel was renamed the Gaillard Cut in his honour. Many years later, after Panama took full control of the canal, the older name, Culebra Cut, returned to common use.

The workers had their own name for this place. They called it Hell's Gorge. Picture the scene. Thousands of men worked in the bottom of a deep trench under the tropical sun, with no shade. Explosions went off nearby. Trains rolled past constantly. Many of these workers came from the Caribbean, especially from Barbados and Jamaica. Their labour built much of the canal, and their descendants still live in Panama today. Their story is as much a part of this cut as the engineering.

The canal opened to shipping in August 1914. But the cut was not finished with surprises. Landslides kept coming after the opening. At one point a slide closed the canal completely for several months. Engineers kept digging, monitoring, and reshaping the slopes for decades. That work continues today. If you look closely at the banks, you may see terraced, stepped slopes. That stepped shape helps keep the hillsides stable and guides rainwater away.

Now look at the two high points on either side of the channel. One is Gold Hill, known in Spanish as Cerro de Oro. The other, across the water, is Contractors Hill. These hills were part of the original ridge that the engineers cut through. Standing between them, you can begin to understand the scale of the task. The water you see now flows through ground that was once solid mountain, removed by hand, by dynamite, and by steam.

The cut has changed in modern times, too. Over the years, the channel was widened so that large ships could pass each other here more safely. Before that, traffic in the narrowest parts often had to move in one direction at a time. Just to the south, the Centennial Bridge now crosses high above the water. It is a cable-stayed bridge, which means its deck hangs from straight steel cables attached to tall towers. Its pale towers make a clean frame for the passing ships.

If you have time, watch one ship pass from start to finish. It moves slowly and carefully. You may see small tugboats nearby and a pilot boat close at hand. Every large ship crossing the canal carries a local pilot, a specialist who knows these bends and currents. At the northern end, the cut opens into the wider waters near Gamboa, where the Chagres River meets the canal. The rainforest there comes right down to the water's edge.

So take a moment before you leave. Look at the green slopes and the brown water. Listen for the deep engine note of the next ship. More than a century ago, this was a raw trench full of smoke, noise, and danger. Today the forest has grown back over many of the old terraces. As you walk away, notice how quiet it feels... and remember that the quiet was very hard to win.