(“Conche di navigazione”)
During the centuries in the Veneto, that was already rich in natural water courses, a close network of navigation canals was dug in order to connect the rivers to each other. This way transports became faster and smoother; moreover the net allowed to improve irrigation and energetic exploitation.
The great navigable net represented for Veneto’s people one primary source of wealth.
By this means all the Veneto cities were connected to each other and to the Venetian Lagoon as well as to the see, the main points of trading.
But the most rivers and canals had differences in slopes and altimetry.
As in other parts of the world, when it was navigated in canals with a little slope or it was gone upstream, boats were pulled ahead by horses, (ridden by the “cavalanti”) or by the boatmen (the “barcari”) themselves, who walked along the banks, called “alzaie” (towpaths).
Locks were built in order to help navigation; these connected canals and rivers that had different altitudes and permitted the boats to sail up and down the waterway.
Once the boats that crossed the locks were pulled ahead by horses.
The locks are made up by a series of sluices meant to hold boats that have to go from a water level to a lower or higher one.
The lock can be a simple or a multiple one one (i.e. a series of river basins one following the other for going up or down gradually).
It consists of a chamber and of two doors, one upriver and one downstream. The boat gets into the chamber through one of them while the other is kept closed acting as a barrier between the two different levels. When the boat has entered the lock also the second door is let shut; then the small buckhead at the bottom of the sluices are let opened so that the water gets into (if the boat is sailing up the river) or out (if sailing down) the chamber.
When the inner water level has reached the external one, the sluice between the two levels is let opened and the boat gets out of the navigation lock.