The first of two TBMs to drive the water transfer tunnel in the Fontsanta-Trinitat area of Barcelona was being prepared for tests in the launch tunnel last month while the second is en route to site.

Seli is undertaking a service contract to JV contractor FCC/Copisa to drive the 5.98m diameter MitsubishiRobbins double shield, which it is renting as well as the back-up equipment. It changed the cutterhead diameter and torque of the shield – now booked as DSU Seli 0598.119 – during a complete overhaul in its workshop.

The shield arrived on site in June and is being prepared in the launch tunnel to advance 200m to a ventilation shaft before, at this launch chamber with also a 100m long half-section tunnel, being set for the main, 5.6km

long drive of the St Just tunnel. The first 200m advance is mainly under consolidation. While SCL lining supports the access and preparatory tunnels, the main bore will be lined with universal segmental concrete rings (5+1) plus inverts, and grout injection.

The job is Seli’s first in Barcelona, and it noted that the JV has an option to buy the TBM and back-up equipment at the end of the excavation, which is scheduled to be completed in nine months. Geology along the alignment comprises mostly schist with some other metamorphic strata, such as grandiorite.

Herrenknecht is supplying the second TBM to another JV contractor – ACSA and Obrascon Huarte Lain S.A. – for the other, 6.2km long, Trinitat tunnel drive on the water transfer scheme to link the rivers Ter and Llobregat. Workshop acceptance of the double shield hard rock TBM (S-424) was in July.

The tunnels will be fitted with pipelines up to 2.4m diameter and the remainder of the bores will provide for security and maintenance access for vehicles. The tunnel will have three intermediate access adits with lengths of 820m, 810m and 33m, respectively.

The scheme is being developed by Aigues Ter Llobregat, part of the Catalunya regional government, to balance out water supplies between the catchments and has a total budget of US$270M.

A pumping station will be built at Fontsanta.

Seli will use a Mitsubishi-Robbins shield for the water bore in Barcelona Herrenknecht is supplying a shield to the project