You may have heard the expression “whatever floats your boat”. On the Danube, the numerous locks between Budapest and Regensburg, Germany are the "whatever" that keeps boats afloat. The stretch of water passing through Hungary, Slovakia, Austria and Germany, changes levels many times and would make water travel without locks, impossible. Think of a lock like an elevator; you step into a chamber, doors close and you’re transported up or down to your destination. Of course the lock process is much more complicated because rather shifting around people, locks are dealing with a large boat and millions of gallons of water. Locks can be found on many rivers in Europe and elsewhere around the world. Did you know the United States has its share? Many American waterways use locks including the Allegheny River, Ohio River and the Erie Canal which originally had 83 locks! The number was reduced to the current 35.
How They Work
Locks are a fascinating bit of engineering. A boat enters a chamber behind gates.
In this photo, the boat is sailing into the lock. On the Danube the lock chamber is generally 81 feet. If the water level on the boat side of the chamber is lower than the level on the other side of the gates, as in this photo, the chamber is flooded with water to raise the boat. When the vessel is at the appropiate level for sailing the waterway, the gates are removed and the boat moves ahead as in the photo below. Compare the concrete walls flanking the ship in both photos, a good indicator of how high a boat can be raised.
The reverse process is used when the waterway is lower behind the gate. After the chamber is drained to match the lower canal ahead, the gates open and the boat passes through. This is all accomplished in just a few minutes. The speed limit on the Danube is restricted to five knots to keep waves under control and avoid flooding the banks of the canals.
Lock designs vary from canal to canal. Some have a single gate, others double. Some are deep, some shallow. Brick and stone are the materials most used for construction. On the Danube, the canal is lined with concrete because of the soft, sandy earth.
Where does all that water go when the lock operates? Tanks hold the water that is drained from locks and it is stored, available for another procedure. About 15 million gallons are transferred in a normal lock operation for one boat. There are approximately 16 locks in a 106 stretch of the Danube River.
Once inside a lock the boat crew goes about securing the boat in the lock.
Claustrophobic passengers may become alarmed by the site of a concrete wall outside their cabin. But the time spent in a lock is minimal and does not detract from the sailing experience for most people. The process attracts the interest of passengers as well as pedestrians outside the lock.
The cold winter climate in Europe could potentially cause problems with freezing lock gates if they were not designed with heaters to keep them fully operational.
Approximately 48 ships navigate the waterway each day. Tonnage, the length of a vessel, and the type of material being transported, are all factors in determining the total cost of a trip on the canal. A typical riverboat will pay around 1000 Euros for passage.
In order for a boat to use a lock, an appointment must be arranged in advance with the gate keeper, more officially known as the Lock Master. It is his job to organize the traffic passing in and out of locks, create a schedule to avoid delays at the locks, and keep in touch with boats for changes in itineraries. With the use of computers, one Lock Master can control a network of locks.
The Highs And Lows of The Danube River
Many elements affect the depth of the Danube at any given time. In 2003 there was little rain and Europe suffered the worst drought in history. Canal water levels reached an all-time low. It was said that you could walk from one side of the Rhine to the other. It was during that time that sunken World War II Nazi warships were discovered in the canal. Three explanations emerged for the ships. One was that the ships were scuttled to make the waterway impassable by the Soviet navy. Another claims the ships sailed into the canal to avoid detection. And yet a third account reports that the ships stalled due to a lack of fuel.
Since planning for the bridges across the Danube began in the time of Charlemagne, the consideration at that time focused on accommodating barges. Finances dictated the height of bridges, creating the situation that continues to be a problem today. Contemporary cargo and passenger ships have to be built to fit under the bridges of the Danube. Raising all the bridges to allow access to taller boats would be financially formidable. But even standard size vessels sometimes run into problems when flooding raises water levels. Riverboat cruises can be cancelled as a result.
The creative ideas of boat builders have minimized the low bridge threat with ingenious solutions. The wheel house on some vessels is adjustable, allowing it to be lowered by hydraulics to accommodate different bridge heights. This is almost standard on container ships today as well as some passenger ships. It’s not unusual when sailing on a riverboat cruise to hear an announcement instructing all passengers off the deck. At times, the boat approaches a bridge offering only a few feet of clearance and deck chairs must be flattened and the wheel house lowered.
The boat captian and his crew consult maps which list bridge heights, and boat sensors which report water depths to determine safe passage on the canal. When necessary, water can be taken on or released to change the ship’s depth.
How Locks Help Commerce
Approximately 48 ships a day travel through the Danube locks, transporting goods from port to port. There are several advantages to using the river for commerse as opposed to other options. Boats produce far less pollution than trains, trucks or other conveyances. They also have no problems with traffic jams, no Sunday restrictions experienced by other forms of transport in Europe, and no necessity for a large number of drivers or an expensive fleet of trucks. One boat can carry far more cargo than one single truck.
More Of My Travel Articles