“Cougar” SC-120/H-8 Hydromill

The equipment used on both these construction sites was the Soilmec H-8 hydromill with a maximum drilling torque of 87 kNm for cutter, mounted on a Soilmec SC-120 crane (120 t category) in the "Cougar" configuration. In this configuration, the machines cut panels with a dimension of 2.800x800 mm; the hydromill's capacity in this configuration is equivalent to 58 m of depth for maximum thicknesses of up to 1,400 mm. The DMS (Drilling Mate System) developed by Soilmec and installed on all the products in the range, in other words the system used for the real time monitoring of all the operating parameters of both the equipment and the production process, includes a dual-axis positioning sensor (triple-axis version optional extra) that controls the geometry of the panel depending on the depth.

Vertical corrections are possible thanks to the following: mobile flaps installed on the main body, variable rotation speed on the excavation discs and the patented inclination system for each excavation disc that ensures optimal orientation along three main axes. In Malaga, the Soilmec hydromill was used to create the support buttresses for a shopping mall in the harbour area.

The new Soilmec “Cougar” SC-120/H-8 hydromill at work in Naples.

The stratigraphy of the area revealed that, under the surface and subsequent layer, varying in thickness from 2 to 4 metres, there was a layer of gravel and erratic chalky sandstone deposits (a type of conglomerate sandstone), characterised by a resistance to compression and lateral free expansion in excess of 1,000 kg/cm2.

The new Soilmec “Cougar” SC-120/H-8 hydromill at work in Naples.

Furthermore, the layer of rock layer to be excavated was often found to be at a depth in excess of 10 m. The SC-120 “Cougar” hydromill is currently in use in Naples for the construction of a station for the underground railway and, more specifically for the creation of “T”-shaped panels of 1,200x2,800 mm and up to 40-45 m in depth. In this case, the stratigraphy is characterised by silty, sandy soils covering the yellow Neapolitan tuff.