The project for the bridge across the Strait of Messina was to connect Calabria with Sicily. The idea was not just to ‘connect’ the two places, it was to create a continuous territory. Perugini chose not to just connect the two sides with a linear connection. It was to create a suspended circular structure with a diameter of 3200 meters.
Suspended 80 meters above the water surface the whole structure consisted of a 70m diameter tubular ring beam. Running along this beam were a railway and highway lanes.
Following Perugni’s interest in computers he envisioned the whole structure to be electronically controlled – shock absorbers woudl dampen the vibrations caused by the wind and the constant tremors of frequent earthquakes in the region.
Containers that woudl move on electromagnetic tracks woudl run along parts of the upper beams and transport people, goods and ‘various equipment’ from side to side.
Perugini sees the structure as ” … a city of services with extreme mobility, whose standards are chaotically located without any organic reference.” (p174).
He continues to describe the technical features:
-theoretical calculation scheme of considerable simplicity (even isostatic for perimetric loads and for symmetric accidental loads);
– section of constant height (70 meters) also in correspondence with the supports (thus avoiding the considerable heights absolutely necessary in the piles of the suspended bridges for relaunching the cables).
– minimum surface exposed to wind actions and complete absence of those phenomena of aerodynamic instability typical of suspension bridges;
– almost total absence of stress states produced by thermal variations from shrinkage phenomena thanks to the particular system of “oscillating supports” provided between the steel structure 10 and the semicircular hollow reinforced concrete structure of the supports;
– ease of adaptation without consequences for any seismic shocks or waves which are always due to the “oscillating supports” mentioned above. (p179)
All images from the Perugini archive
Interview with Raynaldo Perugini in the Maxxi museum in Rome.
Perugini published this text describing the context of the bridge in 1975:
Bridge on the Strait of Messina
Giuseppe Perugini, Progetti e Ricerca, 1975, p169+
«… This is the function of the Perugini project, it is not limited to the solution of the bridge but it studies in depth the arrangement of the territory of the two banks and tries to create a work that is not only the continuation of the highways or the railway line but something more lively, because the work embodies the elements to ensure that in the large suspended circle there is room for commercial activities of various appeal: public places, hotels, etc.
let us try to take a look that detaches itself from the often very limited views of a present, which conditions us, and we look once more!
Messina, most of the times, has even struggled to keep up with the times, especially in recent decades; in fact, the city of the past managed to obtain certain structures and certain elements that qualified it and placed it in the right historical moment, also giving it a valid economic presence, see Messina di Juvara and Palazzata. We are now a fairly delicate and important moment for the history of this city and it is perhaps more for men than ever, for the truest people from Messina, to be able to see now what the future that is being prepared will be. It is not only necessary to think that what is currently a simple need of connection between two territories also becomes the solution to the negative facts that take place within them: a serious analysis must be done, an analysis that keeps in mind the pros and cons that are the basis of this or that choice. You have to notice the economic significance that Messina and its province have. Today Messina bases its economy on the principle of self-sufficiency: the entire social apparatus thrives on trade, “service” and bureaucratic structure. The few industries in the area. municipal have a very limited employment index and their market runs out in the same provincial or even municipal area. The same goes for tourism: the Lido di Mortella and the two lakes of Faro and Ganzirri serve as an outlet and a reference only in the municipal area. The industrial reflection of some centers of the province and of the industrial center of Catania is affected only to a small extent also because of the precarious conditions of the current road system. The only activity that has a certain employment index and which almost gives the city its face is the ferry with those few infrastructures connected to it ».
“What is the beauty of Messina is a fact that comes from what it was since it was chosen by the Greeks precisely for its enchanting position for the wonder of its natural port that stretches safely to embrace the sea of the Strait, unique for the changeability of its coasts, splendid for the spectacle of the whole.
After the completion of the motorway network, the greater speed of travel of the vehicles will reduce the distances between the most emerging poles in the territory, favouring the great industries of the North in selling their products to the detriment of the emerging Sicilian initiatives. In a nutshell the bridge would function as a buffer between the industrialized poles of Sicily and the northern industries: Messina and Reggio would also lose their appearance as “doors” and sorting yards.
The bridge is nothing more than a design element in the field of transport; but transport is only an aspect of urban planning.
If you want to create an effective and non-univocal connection between Sicily and the continent, a connection that is within a Messina-Reggio Calabria conurbation and tourist attraction centre: you must create a complex and complete structure on the Strait; this structure must act as a reference, not a reference for a record obtained with an engineering technique, it is well known that the records precisely because they are fragile because they can be beaten, but a reference due to the activity of the structure that we are proposing. The realization of such a work must then have upstream a planning basis at an urban level in clear connection with the intrinsic activities of the structure, a structure capable of acting as an archetype of a territorial reunification process and as an “equipped axis” with the capacity to fulfill and at the same time overcome the concept of connection, to recover the essential values of this great enterprise and to satisfy all levels of need; perhaps even to propose new meeting points ».
«From a seismic point of view, the area of the Strait, at least in depth, is extremely complex: a large seismic fault starts roughly from the Aeolian Islands, crosses · the mirror in depth and continues towards the Ionian. There is a continuous presence of tremors (vibrations more or less accentuated according to the geophysical phenomena).
From a water point of view, given the enormous • variety and speed of the currents, vortices are generated also due to the transfer of water from the Tyrrhenian to the Ionian Sea, which, rising from depths that are around 150-200 meters, exceeding the saddle on 90 meters, they rush to the other side with accentuated speed.
The speed of the currents reaches about 2.6 meters per second. These currents, which are also found in depth, reverse direction every six hours or so causing upheavals.
The wind creates abnormal and complex conditions. Measuring the wind, on the Strait of Messina, is very difficult because the mass of air has within itself equally unpredictable layers of pressure and depression.
The geological investigation has allowed to find on both the Sicilian and Calabrian sides, recent floods overlying tertiary formations in stratified form with altered granite below.
On the Calabrian shore, the crystalline basement is located at a lower depth, 100-150 meters, while on the Sicilian shore the sedimentary soils have a considerably greater thickness – 300 meters. Neither center of the Strait, the crystalline basement is located about 300-600 meters below sea level. The time limits of the passage in the strait (3 km), the two hours needed, are equivalent to about 200 km of highway.
The last decade has seen three major bridges suspended in Europe. For the first time, these bridges were built outside the United States of America. The first was the “Forth Road Bridge” near Edinburgh in Scotland, completed in 1964; they followed the Tagus Bridge in Lisbon, opened in 1966 and the bridge across the Severn linking England to Wales built in 1966. All these bridges have arches of about 1000 meters. The 1074m high bridge is currently under construction Bosphorus which will connect Europe with Asia.
A suspension bridge of 1400m will be built on the Humber estuary near the town of Hull.
Arches of 3000 meters and more are possible and economically viable in certain circumstances ».