1,600-ton TBM begins 4.4 km Melito Tunnel beneath the Southern Apennines

Excavation has started on the 4.4 km Melito Tunnel, the final tunnel to be driven on the Apice-Hirpinia section of Italy's Naples-Bari high-speed and high-capacity railway.

The drive is being carried out by Aurora, a 12.5 m diameter tunnel boring machine that has already completed the nearby Grottaminarda Tunnel. After finishing that approximately 2 km drive, the machine was dismantled to cross the Ufita River before being reassembled for its next underground journey. Melito is the second-longest of the three tunnels on the 18.7 km Apice-Hirpinia section. Around 13 km of the route, close to 70%, runs underground, reflecting the challenging topography of the Southern Apennines. Aurora is approximately 100 m long and weighs around 1,600 tonnes. Its cutterhead is powered by 18 motors delivering a combined 6.3 MW, allowing the machine to excavate at depths of up to approximately 130 m below ground level.

More than 140 personnel will support continuous TBM operation and maintenance, with tunnelling planned around the clock. As the machine advances, it will install more than 22,200 precast concrete segments to form the permanent tunnel lining. The excavation and lining installation therefore progress as an integrated cycle, allowing the tunnel structure to be completed progressively behind the cutterhead.

The Melito drive follows completion of the 6.5 km Rocchetta Tunnel in May. That tunnel, the longest on the Apice-Hirpinia section, was excavated in approximately 18 months by a second TBM named Futura. Reusing Aurora for consecutive tunnel drives has required substantial logistics between excavations. Moving a machine of this scale across the Ufita River could not be achieved intact, making dismantling, transport and reassembly part of the overall tunnelling programme rather than a simple equipment transfer. The Apice-Hirpinia works extend across the provinces of Avellino and Benevento and also include construction of Hirpinia Station.

The main civil works for the station have been completed, with work continuing on access roads, four roundabouts, eight road connections and a new parking area. The station will have four tracks arranged across two levels and will provide the inland areas of Campania with access to the national high-speed rail network. The wider Naples-Bari programme includes 145 km of new railway and forms part of the Scandinavian-Mediterranean Corridor of the Trans-European Transport Network.

The Naples-Cancello section opened in July, connecting the route with Italy's existing high-speed network at Afragola station. Work is also continuing on the Hirpinia-Orsara and Orsara-Bovino sections. With Rocchetta already completed and Aurora now advancing into Melito, the Apice-Hirpinia section has entered its final major tunnelling phase.