MOSE SYSTEM

 

 

Photo taken from Modus Blog

This picture shows the exact geographical areas where Mose mobile dams will work.

 

 

MOSE system was originally thought to defend Venice from the damages caused by the "acqua alta", when the water comes in from three zones in front of the dock of Venice (three "bocche": from North to South there are "Bocca di Lido", "Bocca di Malamocco", "Bocca di Chioggia" ). When they forecast a change in the level of the sea higher than 110 centimetres, Mose system is put at work.

Basically, they thought to close all the three entrances of the water in the dock thanks to a system of mobile doors integrated with other works to defend urban zones frequently affected by the problem of "acqua alta". 

The system is thought to interfere with the dock commercial activities ( it has a navigation channel at the "bocca di Malamocco that is 370 metres long that was built for this reason) as less as possible, because is built in a way that allow to close it only three or five times per year, during the emergencies to avoid big changes in the level of the water. It is also built to damage environment as less as possible and is useful also to maintain the water of the dock quite clean. 

 

 

TECHNITAL S.p.A. and the realization of Mo.S.E.

 

TECHNITAL S.p.A. is working at the project to safeguard Venice: the company is one of the most important consulting engineering firms worldwide whose main technical office is in Verona. The main national object of this leading engineering firm is the defence of the lagoon basin from the damaging effects of high tides. The solution found by the company involves the separation of the lagoon from the sea due to MOBILE BARRIERS. These mobile barriers consist of rows of gates fixed on the lagoon inlets of Lido, Malamocco e Chioggia: under normal tidal conditions the barriers are full of water while, when high tides are forecast, they introduce compressed air into the gates in order to expel water. That means the inlets are only closed for the duration of the high tides and for the time they need to open and close the gates (they calculate it takes, on average, something like four and one-half hours). A life size prototype of a gate has already been constructed, it is the so called Mo.S.E. (Modulo Sperimentale Elettromeccanico).

 

 

 

How does Mose works?

 

Works to build the system are going on at the same time in the three "bocche". They started four years ago and are now completed at 30%. About 700 people are working on them at the moment. Works are to be done in three steps to be completed in eight years starting from their offivial opening in may 2003.

The first step has been completed yet: it was composed by some works and studies that were done to prepare the installation of the doors on the three "bocche" of the dock.

The second step,  now in progress, is the construction of the main platforms for the doors of the system, as well as some little docks and channels for small ships (like fishing ships, rescue ships) in the "bocche" of Lido and Chioggia" and the big navigation channel at the "bocca di Malamocco".

Last step will consist on the installation of the doors and the protection of the areas in front of those doors.

At the end of the works four lines of doors will be build up (one at Malamocco, one at Chioggia, two at Lido).

The system consists in those four lines of horizontal doors that when the level of the water is at its usual are full of water and lie in their boxes on the bottom of the dock. When they forecast that the level of the water will change more than 110 cm, doors are inflated with air to push out the water to let them emerge until they stop the flow of the water coming in the dock. Then, when the water of the sea returns to its normal level that is at the same level of the water of the dock, doors are again filled in with water in order to make tham sink in their boxes. Doors remain closed only during the "acqua alta", more or less for four hours and a half. 

 

 

Mose: a very controversial project

 

 

Mose system was and still is a very controversial project. On one hand there are the Venezia Nuova Group, the CORILA that together with the Water Authority are promoting and defending the Mose by declaring it is the best way for saving the town and its lagoon, while on the other some other people are arguing it will make the situation even worse like e.g. the Assemblea Permanente No Mose, Venice municipality and its Mayor Massimo Cacciari – who may invite Al Gore to the International Conference on Climate, the Lagoon and Mose that will take place in Venice within april – and other engineers such as Fernando De Simone, Vincenzo Di Tella, Antonio Tamburini, etc. who have studied other ways for solving the "acqua alta" problem.

 

It is really hard understanding if the Mose might save Venice and its lagoon or on the contrary deteriorate it without solving anything, because it is a scientific diatribe and at the same time a political one.

 

Alternative projects to the Mose

 

 

There are 9 different alternative projects to the Mose that have been proposed to Venice Municipality for saving the town and its lagoon in the last years.

 

1. Gravity gate - Paratoia a gravità (proposed by Vincenzo Di Tella). This project is called Mose2 as well because it consists in a corrected Mose. According Di Tella the main fault of the Mose is that it rises to the surface underset and this might provoke its collapsing, whereas the gravity gate would exploit the tidal current and model itself to it.
    
2. Mast arms – Bracci a traliccio (proposed by Fernando De Simone). The idea is to place steel cylinders next to every dock that float thanks to compressed air and to sink them by filling them with see water.
    
3. Doge (proposed by Antonio Tamburini). Doge would consist in a flexible underwater dam made by different units that are filled with see water in order to make them bigger enough for reducing water flowing into the lagoon without obstructing sea traffic.
    
4. Ve.Perla (proposed by Cesare De Piccoli).  
    
5. Arca 2005 (proposed by Antonio Ieno). This system is quite similar to Doge but instead of an underwater dam it would use self-sinking ships for creating a submerged barrage.
    
6. TMT Italia (proposed by TMT Italia).
    
7. Rubber dam (Fernando De Simone). It works exactly as Doge.
    
8. Navi porta (proposed by Alberto Pellegrinotti). As the mast arms and Arca 2005 do the idea is using steel cylinders similar to ships and to make them sinking.
    
9. Study for saving Venice (proposed by Massimo Ermenegildo). This project suggests to separate Venice and the north part of the lagoon from the south one and to install mobile barrages only at Bocca di Lido.

 

According these engineers and  the Assemblea Permanente No Mose the alternative project should replace the Mose that is too expensive and can not solve the “acqua alta” question but only destroy the lagoon ecosystem.

 

 

 

 

Sources

 

• www.salve.it/it/soluzioni/acque/f_avanzamento.htm
• http//www.infrastrutturetrasporti.it/page/standard/site.php?p=cm&o=vd&id=1437
• Corila: Valutazioni sulla Documentazione presentata dal Comune di Venezia alla Presidenza del Consiglio dei Ministri in merito agli interventi per la salvaguardia di Venezia e della sua laguna. 30 settembre 2006. Retrieved on 10 April 2007 from pub.corila.it/DocumentiPubblici/AttivitaInterneCorila/SitoCorila/News/ValutazioniCORILA300906.pdf
• Assemblea Permanente No Mose, Perchè non vogliamo il Mose. Retrieved on 10 April 2007 from http://www.nomose.org
• TECHNITAL S.p.A. - A leading International Engineering and Consulting Firm operating in Italy and abroad since 1964. (2004). Retrived April 10, 2007 from http://technital-spa.com/
• Silvio Testa. Paratoia a gravità. Retrieved on 10 April 2007 from http://www.fareverde.it/informati/articoli.php?azione=dettaglio&id=49
• Silvio Testa. Arca: Un'alternativa al Mose. Retrieved on 10 April 2007 from Eddyburg.it
• Comune di Venezia. Verbale X' Commissione. Retrieved on 10 April 2007 from http://www2.comune.venezia.it/str/commissioni/v_10_6.asp  

• Bracci a traliccio. Retrieved on 10 April 2007 from http://66.102.9.104/search?q=cache:hdL7y1_0jgsJ:www2.comune.venezia.it/mose-doc-prg/documenti/mose/2_BRACCI%2520A%2520TRALICCIO.pdf+bracci+traliccio+de+simone&hl=it&ct=clnk&cd=1&gl=it

 

 

 

 

 

 

 

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VAJONT

Vajont is the name of the stream which flows  in the valley between Erto and Casso, in Belluno.  The population of these two towns experienced one of the world’s worst catastrophes when, in the night of  9 October  1963, a monstrous wave rose over the Vajont dam.

First Projects

The waters of the river Vajont had always been seen as a great energy source ever since the year 1900. In this year Gustavo Protti made the first request to build a dam 8 meters tall in order to obtain from it a good amount of “forza motrice” for his paper mill. About 25 years later the river began to be seen as a possible source of hydroelectric power.  In 1929 the engineer Carlo Semenza made his first project for a great dam in Vajont. In those years he was working to this project for the Società Idroelettrica Veneta. According to this first project the dam had to be 130 m. high and hold 33 million mc of water. In 1937 the Società Idroelettrica Veneta was integrated i n the SADE which asked Semenza to complete and better his project on the dam. In this second project/ Now the dam was going to be 190 m high and was going to hold 46 million mc of water. This dam was going to be built near the Colombèr bridge. In the following years this type of energetic exploitation of rivers reached other rivers as well, and in 1940 the project "Derivazione dai fiumi Boite - Piave - Vajont: fusione e coordinamento di precedenti domande" was elaborated.

The construction of the Vajont dam

In 1953 the new president of the SADE, conte Vittorio Cini, was fascinated by both the valley and the dam project of Vajont. Semenza’s  dream to see  the realization of his project of the highest dam in the world was now going to be fulfilled. Unfortunately, the procedure followed was not the legal one.

The constuction began in 1956 when the SADE had not obtained all the permissions yet. The final aim of building the dam which would complete the project of one of the biggest hydroelectric plants in Italy was more important than any legal procedure. This is when the first big mistake of the Vajont dam was done. From a geological point of view the valley was not  adequate for a dam like the one wanted in the last project.  Moreover, there had been many protests. The mayor of Longarone was affraid of what this dam could have caused to the lands along the river, which would not recieve any more water; the mayor of Erto and Casso protested saying that a loto f lands would have been submerged; other local entities objected the negative effects the dam would have had on landscape and, therefore, on tourism.

source

Disastro del Vajont. retrieved on 07 april from http://www.vajont.net/