-Channel allows ships to bypass, circumvent the locks with the help of hydroelectric dams.

  Gateway - a lift for ships. If the river by dams, the water level in front of her, in the reservoir is much higher than in the river downstream. To rise to the level of the reservoir, a vessel coming from the lower, comes a gateway - part of the channel, separated by two watertight gate - top and bottom. As soon as the vessel entered the gateway, the lower gates are closed. Then open the upper gate. It starts with filling the gateway, and the ship rises to the level needed. Through open the top gate ship goes into the reservoir and continues the path. Descent of vessels coming down the river, carried out in reverse order.
  More recently, instead of locks on some rivers began to use the boat lift. The ship enters the chamber of the lift in the same way as in the gateway, and together with the chamber rises or falls. And then the entire camera is moved by rail to the other side of the dam, where the vessel is released into a river.
  The largest maritime gateway Berendreht is located in Belgium. It connects the river Scheldt in Antwerp docks. Gateway opened in April 1989, the length of his cell - 500 meters, width - 68 meters depth on the threshold of the gateway - 13,5 m, weight of each of the four sliding gates (gates) - 1500 tons. Construction of Gateway cost approximately $ 12 billion Belgian francs. In Belgium and is the gateway to the largest rise from one level of the river to another - 68.58 meters. This lock - lift at Ronkera on channel Charleroi, Brussels. Two 236-wheeled caisson carrying capacity of 1370 tons each on an inclined plane covered a distance of 1,432 meters within 22 minutes. Deepest Gateway - "Zaporozhye” is on the Dnieper-Bug Canal, Belarus. He can raise and lower barges to a height of 39.2 meters.
  The remains of the oldest canals in the world were discovered near Mandali in Iraq They dating archaeologists IV millennium BC.
  Today is the longest canal system in the world - the Volga-Baltic Waterway (formerly the Mariinsky water system). It was built in the XIX century, and connects the Volga with the Baltic Sea, and in the White Sea-Baltic Canal - from the White Sea. In 1964, after a major reconstruction, this system became available for vessels of 5 thousand tons. The path length - 1100 km, and depth - not less than four meters.

  The busiest is the Kiel Canal, connecting the North and Baltic Sea in West Germany. In 1987 it was omitted from 45 000 vessels.

  Second place goes to the Suez Canal - more than 20 000 vessels per year, the third - Panama Canal - more than 10 000 vessels per year. On-duty ship in the first place is the Suez Canal, it held court with a total displacement of almost 440 million tons.

  The opening of the Suez Canal in November 1869. Napoleon's engineers laid in draft multiple gateways, because by their calculations, the difference in the level of water between the Mediterranean and the Red Sea was 10 meters. But after it became clear that this was wrong, it took a lot of time to implement the idea.

  Canal was planned by the French diplomat, Count Ferdinand de Lesseps. In 1854, he has difficulty with the consent of the Vice-President Mohammed Said Pasha (Egypt at that time was part of the Ottoman Empire) and received the right to begin construction. Canal, beginning north of Suez, was in a straight line across the lake Timsah and Bitter Lakes and reach the Mediterranean Sea. De Lesseps was able to enlist the support of Vice President. He also managed to attract a number of French shareholders who have invested in the construction of the Suez Canal. Surprisingly, the British, more than others benefiting from the reduction route to India (the channel reduced the distance between London and Bombay in 7343 kilometers), have not bought any shares. Moreover, the British government has done everything to prevent this project. It condemns it as physically impossible, too expensive and unprofitable.
  The length of the finished channel was equal to 161.9 kilometers from the lighthouse at Port Said to Suez-Rhodes, depth - 8 meters, and width - 60 meters. Every 10 kilometers had been dug a spare bay. Today the channel width is 200 meters, and there is no place where the depth would be less than 15 meters. As it may take a fully loaded oil tanker twelve draft.

  De Lesseps was a great journalist and a manager. He organized a lavish opening ceremony. In 6000 guests were invited 500 cooks and waiters 1000. The famous composer Giuseppe Verdi's opera commissioned for the inauguration of the channel and the new Italian Theater in Cairo. Thus was created "Aida."

  With the name of Ferdinand de Lesseps associated construction of another famous canal - Panama. Alas, the first attempt to dig the channel failed. De Lesseps established a new company. That in 1881 pledged to undertake this work and to dig up from the ocean to ocean bed depth of 9.1 meters and a width of 22 meters at sea level. Unfortunately, the difficulties were insurmountable. The main cause of failure was not hard rock ground, but an epidemic of the disease with jaundice and malaria. Construction has become a fatal trap and enjoyed a bad reputation. There is evidence that they killed about 20 000 people. The company went bankrupt in 1889.

  In 1904, Panama and the U.S. signed an agreement whereby the right to build the channel switched to the latter. Taking into account the previous attempt, in this area was sent a U.S. military doctor, William Crawford Gorgas. In the two years he coped with jaundice and took control of malaria. In 1907, the construction of the channel, now on a different plan, resumed. The colonel of army of USA ordered George W. Getalz.
  August 15, 1914 the first ocean liner was the Panama Canal, linking the Atlantic and Pacific Oceans. The channel length - 82,4 km. Contrary to general impression, he does not go in a straight line from east to west, because the very geography of the Isthmus of Panama from Colon transmit channel on the Atlantic Ocean to Panama City on the Pacific Ocean, south-east.
  At both ends of the waterway had been built ports, as well as many other structures: breakwaters, dams, sluices and artificial lakes. Yes, and most of the railway between Colon and Panama City also had to lie again.
  At the end of the canal from the Atlantic, the court sent to the three Gatun’s gateways, where they were raised to a height of 26 meters to the artificial Gatun Lake. For this lake on the channel width of 150 meters there are already other gateways. There, the court dropped first to 9.5, and then to 16.5 meters to sea level and are included in the Pacific port at the Panama Bay. Both the entrance to the channel are insured by giant wave breakers.
  Height gateways - 305 meters, width - 34 meters. All gateways are bilateral, therefore all ships that come from opposite sides, can swim without interfering with each other. The thickness of the huge steel gates of the locks - 2, 1 meters and height - up to 25 meters. Small diesel engines, moving along the walls, slowly conducting a vessel through the gateway. Usually in a single vessel is required, six of these machines.

  With the reduction: http://www.tiptoptech.net/chanal.html