Type of tunnel-tanks delimited by end walls forstorage of fuels or liquids in general.

This type of tunnel-tank has won specific International Tenders “ Design and Buid”called for by the Italian MOD for the construction of logistic depots (protected against war attacks) as well as by NATO and Middle East oil companies for their underground fuel stocks.This innovative type of tunnel-tank is based on the design of two specific compatible structures; the static and the metallic (fuel containement) ones. Both stuctures are suitable to grant, as far as storage is concerned,the maximum capacity of the internalcavity of the inner static structure, approximately 98% of the capacity delimited by the intrados surface. All welded seams are drained by the set of small vertical and horizontal ducts surroundingall the liner’s elements. The double tightness of the tank is also there by obtained which, in addition toensuring the complete absence of leakage, lends the containment steel structure the equivalent tightness of the traditional“double wall” or “double jacket” tank.The set of small ducts permits the detectionof any possible defect (discontinuity) which could possibly occur in a weld. In such event a drop of the stored fuel, passing through it, could only permeate in that specific small duct and remain hermetically confined there. This is why the tank retains, in any event, its characteristic tightness. This type of tunnel-tank, delimited by endwalls, in accordance with the FERRARI Patents,permits the underground storage of huge fuel quantities in an entirely ecological way, fully safe guarding both the environment,which remains intact, and avoid ingany remote possibility of polluting underground water-beds. The metallic structure is made of steel plates,of commercial type, with a low carbon content, 5 mm thick and 6 mm at the bottom. Steel sheets are placed at short distance from each other and are welded horizontallyto flat steel profiles and vertically to those with an omega section; the down flow of the monitoring ducts, subsequently covered with flat profiles, is thereby obtained.The horizontal ducts join into the main vertical ones with an omega section that ends with a small tube which enters into the passage underneath for the visual check. Installed at the very end of the small tube(either singly or in sets) are the interception electro-valve and the element with a sensor, which, in case of fuel exhalation (inside the pipe in question), automatically closes the electro-valve, thus stopping and confining the possible leak age within it. The steel structure is positioned at short distance from the intrados of the tunnel static structure (approx. 7cm) and is connected with anchors to  which spacers areattached in order to create an interspacewhich is then filled with oxidated bitumenliquified at 220o.Therefore, bitumen is the natural isolationthat prevents the aggressive effectof macrostack (soil/metal) on the steelstructure.The innovative monitoring system permits,with an empty tank, the location of theexact point of a possible weld defect, bypressurizing the small vertical duct withcompressed air and visually locating theexact point from which the air flow comesout and then repairing the defective partby welding.A potential use of this tunnel-tank thatI would consider feasable, could be the temporary storage of refluent waters; eventhose contaminated by radiation and to be subsequently decontaminated. It suffices to consider what is happeningin Fukushima, where the contaminated seawater of the nuclear plant is slowly be ingtreated by reverse osmosis.I believe that this type of tunnel-tank, delimited by end walls, because of its huge contain mentcapacity may be particularly suitable for the strategic storage of huge fossilfuel quantities in order to meet the energydemand in the event of an extraction crisis. This technology ( the steel contain mentstructure) is now being used, within NATO for military airports in Poland, to build huge external cylindrical tanks having a peripheral structure in reinforced concrete to be subsequently placed underground. Furthermore the use of a pre-stressed reinforced concrete structure, because of it sperfectly tightnessf eatures, guarantees the complete tightness of the tank it self.