Exploring Europe’s River Locks: How They Work and Must-See Locks on a River Cruise

When cruising the rivers of Europe, one of the most fascinating aspects of the journey is passing through the river locks. These engineering marvels not only serve a crucial function in river navigation, but also add a fun and unique element of river cruising. Typically, your cruise captain will announce when a lock is coming up in the river. If you’re inside the ship, the light gets blocked and it can momentarily seem as dark as night, even during the day. When it is safe, I recommend experiencing the locks from the upper deck so you can watch the action and see the difference in river heights. Keep reading more below to learn how river locks work and take note of some of the top locks you’ll encounter on a European river cruise, including the tallest lock in Europe, located in Portugal.

How River Locks Work

A river lock is essentially a device used for raising and lowering boats between stretches of water of different levels on river and canal waterways. Locks play a vital role in river cruising, especially in regions with varying water levels, such as the Danube, Rhine, and Douro rivers.

Here’s a step-by-step breakdown of how a river lock works:

1. Entering the Lock: As the riverboat approaches the lock, the lock chamber (the space where the boat will sit) is at the same water level as the section of the river the boat is currently navigating. The lock gates open, allowing the boat to enter the chamber.
2. Sealing the Lock: Once the boat is securely inside the lock chamber, the gates behind it close, sealing the boat inside the chamber.
3. Adjusting Water Levels: The lock operator then either fills or drains the lock chamber with water. If the boat needs to be raised, water is allowed to flow into the chamber, increasing the water level and raising the boat. Conversely, if the boat needs to be lowered, water is drained from the chamber, reducing the water level and lowering the boat.
4. Exiting the Lock: When the water level inside the chamber matches the water level of the next section of the river, the gates in front of the boat open, allowing the boat to continue its journey.

This process may take anywhere from a few minutes to over an hour, depending on the size of the lock and the difference in water levels. Passengers aboard river cruises often gather on deck to watch the entire procedure unfold, making it a unique part of the river cruising experience.

Top River Locks to See in Europe

Europe is home to many impressive river locks, each offering its own unique charm and history. Here are some of the top locks you can experience on a European river cruise:

1. Carrapatelo Dam, Portugal (Douro River)
   • The lock at Carrapatelo Dam is the tallest lock in Europe, with a height difference of 35 meters (approximately 115 feet). Located on the Douro River, this lock is a true engineering marvel, enabling riverboats to navigate through the steep and picturesque Douro Valley. Passing through the Carrapatelo Lock is a breathtaking experience, offering stunning views of the surrounding vineyards and terraced landscapes.
2. Niederfinow Boat Lift, Germany (Havel-Oder Waterway)
   • The Niederfinow Boat Lift is one of the most remarkable locks in Europe, located on the Havel-Oder Waterway in northeastern Germany. Built between 1927 and 1934, this vertical lift lock raises boats 36 meters (118 feet) in the air, making it the oldest working boat lift in Germany. A newer lift, completed in 2020, stands alongside the original. While this one isn’t common to experience on a river cruise, if it interests you, it can be experience on the Berlin to Copenhagen cruise along the Oder with CroisiEurope.
3. Lock of Ecluse de Bollène, France (Rhône River)
   • The Bollène Lock on the Rhône River is one of the deepest locks on the Rhone River, with a drop of 23 meters (75 feet). Located near the town of Bollène in southern France, this lock is part of the hydroelectric power station at Bollène, making it a crucial piece of infrastructure in the region. Passing through this lock is a dramatic experience, especially given its size and the volume of water it handles.
4. Main-Danube Canal Locks, Germany
   • The Main-Danube Canal, a 106-mile-long canal that connects the Main and Danube rivers, features a series of 16 locks that are among the most significant in Europe. The canal crosses the Franconian Jura Mountains, requiring locks that can handle significant changes in elevation.
5. Melk Lock, Austria (Danube River)
   • Situated near the famous Melk Abbey, the Melk Lock on the Danube River is one of the many locks that help boats navigate the river’s varying water levels. The scenic surroundings, including views of the abbey and the Wachau Valley, make this lock particularly memorable for those cruising the Danube.
6. Schleuse Regensburg, Germany (Danube River)
   • The lock at Regensburg is a key feature of any Danube River cruise. Located near the historic city of Regensburg, this lock is not only functional but also offers picturesque views of the city’s medieval architecture. The experience of passing through this lock is often a highlight of Danube cruises.
7. Koblenz Lock, Germany (Rhine River)
   • The Koblenz Lock is a crucial structure on the Rhine River, helping vessels navigate the waterway near the confluence of the Rhine and Moselle rivers. The area around the lock is steeped in history, with the famous Deutsches Eck (German Corner) just a short distance away, where a large equestrian statue of Emperor Wilhelm I stands.

River locks are more than just functional structures; they are an integral part of the river cruising experience in Europe. Each lock is unique, and passing through them offers a glimpse into the engineering feats that make river travel possible. Whether it’s the towering locks of the Douro or the scenic passage through the Wachau Valley, these locks add a unique and fascinating dimension to any European river cruise.

So, next time you find yourself aboard a riverboat in Europe, take a moment to appreciate the intricate process of navigating through these locks. It’s one of the many reasons why river cruising remains one of the more enchanting ways to explore the continent.