The city of Venice is set in a vast lagoon syste , made up of islands and canals. The regulation of navigation in this difficult stretch of sea has always been an important aspect of life in this area. As a major city of the plains is essential to have a good road system , which ensures adequate traffic distribution and a high degree of security , so for a city like Venice, a system of canals plays a role of primary importance.
The pillars on which rests the organization of vessel traffic in the lagoon are the catapults ( in international maritime nomenclature are called " duc d' albe ", " Dalben " or " dolphin" ), a set of three stakes driven into the ground and emerging from the water for part of their length , used to delimit the waterways .
These poles numbered provide boaters a wealth of information about the depth of the seabed , the changing of the tides, etc. . The lagoon is literally dotted with these catapults, but their exact number is not known, although reliable estimates speak of an amount of between 60,000 and 90,000. As the pillars of the buildings in Venice , the poles that make up the mooring posts are made primarily of European oak, have an average length of 10-15 meters and a diameter of between 35 and 50 cm . Once exhausted must be replaced to prevent , cracking , becoming a hazard to navigation .
For years, briccole was manufactured using wood from France and Germany, countries with FSC and PEFC certified forests whose wood mass is continuously expanding.