Spoleto is an ancient city in Umbria, Italy. It is surrounded by hills and vineyards and is famous for its churches and magnificent bridge. The fourteenth-century bridge called Ponte delle Torri (Bridge of the Towers) was derived from a Roman viaduct and is the symbol of Spoleto, as well as one of the city’s most panoramic points. It was, in fact, first an aqueduct, originally built by the Romans and then rebuilt (or expanded, according to some sources) in the 12th century. It spans the deep ravine and ensures a reliable water supply to Spoleto.
Connecting the hillside to the city’s high point, both ends of the bridge feature a fortress: the Rocca Albornoziana on the city side and the Fortilizia dei Mulini on the other. These two fortresses, with battlements and towers, gave the bridge its name. The Rocca is the highest point in Spoleto. The bridge is 230 metres long (787 feet) and nearly 80 metres (262 feet) high, featuring nine graceful arches. The top of the aqueduct has a walkway outlined by a parapet and is open to foot traffic.
Underneath this walkway, drinking water pipes were buried in the 1890s to carry water from one side of the ravine to the other. Years of use resulted in heavy leakage that began to damage the viaduct. It was decided that the historic structure needed to be protected, and consequently, the pressure pipes, which operate at 3-4 bar internally, were relined.
As traditional digging was not an option WPR, the expert relining company in Italy, and ASOE cleaned the pipes using pigging, and then the hose lining was pulled into place and sealed at each end with pressure couplings. The lining took a few hours and allowed the pipes to be completely sealed, reopening the viaduct to the public. Two lines of over 350 metres each were installed in one pull.
Thames Water attended the site with their Tier 1 contractor, Cappagh Contractors Construction (London), to evaluate the project and explore the opportunity to use this technology within the Thames Water area. They were pleased with the materials, installation techniques, pressure testing, and handover. Dean Hansford, Trenchless Contracts Director for Cappagh, said: “It’s been great to see the simple and efficient method of installation and the range of options that this product offers. We will definitely be looking for opportunities to collaborate with ASOE in the UK with our current and future clients.”
Michele Libraro, CEO at WPR, commented, “The project had been challenging but was completed ahead of time.” Deon Pohorille from NUFLOW and ASOE also commented saying: “This was another monumental project for ASOE, and we are looking forward to supporting Thames Water and Cappagh with their challenges and future installations in the UK.”
