The controlled use of explosives ensured that the 100m weather tower, 150m reinforced concrete chimney and two 50m-high steel boilers weighing 2,000t were demolished in only five seconds each - but the assignment took more than 12 months to prepare for.
The two old oil units of EP Produzione’s thermoelectric plant in Fiume Santo – each with a nominal power of 160MW – were permanently shut down in December 2013, after having supplied energy to the Italian island since the 1980s. A phased decommissioning programme has been under way since the closure, but specialist consulting engineers from UK-headquartered RVA Group were appointed last autumn, to oversee the use of explosives on the site.
The blowdowns took place as three individual mid-week operations, with 50kg of explosives used throughout.
RVA’s explosives expert Charles Moran said: “Explosives engineering was the preferred technique for these assets because of the height of the structures. It was considered safer to demolish them remotely, than expose employees to thousands of unnecessary hours working at height.
“Given the complexity of the project and the several counterparties involved, a constant dialogue was needed with local and national institutional bodies responsible for environmental authorisations and the import of the explosives. Our technical knowledge and experience was certainly placed under scrutiny.”
Using a shaped-charge technique specified for the boiler demolition, RVA worked with explosives contractor Tecnomine and author of the blasting projects Mr Mikula, to develop the methodology. Test blasts were also attended in Spain to refine the explosives design before the blowdowns took place.
All of the resulting 8,000t of material has been recycled, with the concrete processed through a local crushing plant and the steel being sent for scrap. Main contractor AVE – based in the Czech Republic – is now dismantling the remains of the boiler and clearing up the wider site.