BESSAC is specialized in the construction of tunnels and microtunnels as well as in the manufacture of equipment for underground works. 

BESSAC has been performing underground structures for more than 50 years to serve a variety of applications including sewers, utility tunnels (electrical networks, drink water, Oil&Gas), sea intakes and outfalls (sewer, desalination plant or energy) and metros. 

 BESSAC masters of all mechanized tunnelling excavation techniques (slurry microtunnelling machine, earth pressure balanced TBM, slurry TBM, hard rock TBM) and has completed over 150 km of tunnelling and microtunnelling projects in the last 10 years across 5 continents.