3.1.4.4 BES system The BES slab track system is consisted by a reinforced concrete bearing layer (CBL) with individual support points over the cement stabilized layer (HBL) (UIC report15, Franz29). This system was developed in Germany and uses the same process as the FFC in producing the form of the rail fastening at the installation of the CBL. The plugs for the rail screws are glued into pre-drilled holes in the dried concrete supportive layer (Franz29).