The work and the technique: Naples-Bari High-Speed Railway Line

The high-speed/high-capacity rail line between Naples and Bari will span 145 kilometers, featuring 15 tunnels, 25 viaducts, and serving 20 stations. Its construction—particularly along the Apennine stretch, marked by highly complex geotechnical and geomorphological conditions—will involve the use of no fewer than eight tunnel boring machines (TBMs).

In 2018, the Webuild Group began working on two of the four sections under its responsibility for the Naples-Bari High-speed/High-capacity line.

The four sections are: Naples-Cancello, which will allow for the connection of the Naples-Afragola HS railway, an important regional/HS interchange hub for passengers; the 18.7km Apice-Hirpinia section, which cuts through the Apennines, with 3 tunnels and 4 viaducts, as well as the intermediary station of Hirpinia; the Orsara-Hirpinia section, which spans some 28km, nearly all of which is in a tunnel (approximately 27 km); and the 12km-long Orsara-Bovino section.  

Works involve some premium engineering interventions like the Casalnuovo Tunnel - on the Naples-Cancello section - built by excavating in a hyperbaric environment, a cutting-edge technique on the international panorama in the construction of tunnels that interact with the water table.  This type of approach makes it possible to use compressed air as a method for carrying out excavation and lining works in dry conditions, offering significant advantages from both a practical and an environmental standpoint, as it avoids the risk of cement mixtures coming into contact with the water table. The Casalnuovo Tunnel, 650 meters long, was completed in July 2025.

Another cutting-edge engineering solution adopted along the Naples–Bari high-speed line was implemented on the Naples–Cancello section during the launch of the third and final steel arch bridge - completed in the summer of 2021 -  with a length of 80m, a width of 13m, and an arch height of about 21m for a total weight of 2,500 tonnes. The bridge was assembled in a specially created space near the operating roads. It was raised at launch height, at approximately 6 metres from street level, using lift towers, strand jacks and hydraulic jacks. Subsequently, 18 special large conveyor trucks distributed the total weight over 104 rubberised planks, taking the bridge to its final position on its supports, in approximately 10 hours.

Another feature of these works is that of minimally impacting mobility and existing activities. Among these is the shopping center 'Le Porte di Napoli', located along the Naples–Cancello section. The Naples–Bari high-speed line includes a stop known as 'Fermata Centro Commerciale', located on a viaduct that crosses over the 'Le Porte di Napoli' shopping center, To build it, a careful logistics service was used to safeguard the normal daily activities during works, involving machinery moving hundreds of cubic meters of concrete into the site and of the same amount of excavated material out of it.

The Apice-Hirpinia Lot, meanwhile, involves the construction of 18.7km of works, 13km of which will be in tunnels, including three tunnels built using two TBMs. The project also includes the construction of the new Hirpinia station in Grottaminarda, intended to serve the provinces of Avellino and Benevento, as well as the construction of a new stop in the small town of Apice.

The Hirpinia-Orsara section is the central stretch of the Naples-Bari route. The route involves a total of 28km of line which runs predominantly underground through the 27km-long ‘Hirpinia’ tunnel - which trains can travel through at a speed of between 200 and 250 km/h - making it a contender for the record of longest tunnel in Italy (currently held by the Valico tunnel in Genoa).

Finally, the doubling of the Bovino-Orsara section will be the final lot of work performed on the line before it is reconnected to the Bovino-Foggia-Bari line, which has been in operation since 2017. The route spans an overall length of about 12km and runs predominantly through a natural tunnel (the Orsara tunnel, around 10km long) which can be travelled through at a speed of between 200 and 250 km/h.