Navigation Locks & River Cruises
by Leslie Russell
The diverse and fascinating geography of the European continent has blessed it with magnificent and varied natural sights. Mountain ranges such as the Swiss Alps, the French Vosges, Germany’s Fichtelgebirge, and the Black Forest region have given birth to the great rivers of Europe, which have provided most important transportation links since ancient times.
Before the advent of highways and road transportation, the rivers were the only efficient method of carrying goods from one place to another. Those most important trading centers located on a river soon grew into some of Europe’s most important cities—Budapest and Vienna on the Danube, Strasbourg and Cologne on the Rhine, Mainz and Frankfurt on the Main, and Koblenz and Trier on the Moselle, to name but a few!
The challenge facing the early navigators was how to tame the rivers and make them navigable along their entire lengths. One answer was the invention and development of the lock.
Normally, water levels on each side of a navigation lock are different, so a lock has to work like an elevator. This is accomplished by using two sets of gates to enclose a chamber.
The lock starts with one set of gates open, and the water level in the chamber is the same as the water in the channel on that side. A vessel enters through the open gates. Once the vessel is moored inside the lock chamber, the lock operator closes the lock gates behind the vessel.
With the vessel securely tied up and the gates closed, the lock operator can then open the valves at the opposite end of the lock. To adjust the water level in the lock chamber to match the water level of the waterway on the opposite end, water is allowed to enter into the chamber from the high-water side or drained out of the chamber to the low-water side, thus raising or lowering the ship.
Once the water levels are equalized, the gates at that end are opened and the vessel can continue on its way.
