This is a large-scale expansion intervention of the workshop building and main building of the FGC Operational Centre in Rubí with three main objectives: - To cover the old road of dynamic tests for storage and museumisation of various historical units. - To provide a new façade and image to the access street to the centre, while giving greater privacy to the homes in the nearest suburban core. - To act as an exhibitor of the historical units towards the car park and access to the centre's offices. The scale of the workshop and office building - with a larger surface area than a block of the Cerdà plan - and the length of the dynamic test track to be covered, required a forceful and symbolic intervention, which at the same time give material and volumetric continuity to the centre and provide a contemporary image in tune with the institution's current requirements. A long structure is projected adjacent to the workshop building of 173.00m in length and continuous section in the form of an arch that avoids the problem of distinguishing between façade and roof and that, resting on the existing concrete wall that delimits the perimeter from the centre and formally separating from the workshop building, it creates an optimal transition between the existing curved and inclined roofs and the street, towards which it becomes the new image. This structure is clad on the outside with continuous smooth sheet metal with a tab joint, avoiding any joint in section and providing a continuous rhythm along the entire length of the new ship, only interrupted by the emergency staircase - an expressly unique volume, exempt from the main structure— and by the spelling of large corporate letters that subtly present the institution and mark the main access. Inside, this structure is presented in a rational and completely naked way, enhancing its tectonic beauty and marking a constant rhythm that is surprising for its length. The inner lining of the arched enclosure is also made of sheet metal - this grooved, indented, micro-perforated and arranged over large thicknesses of thermal and acoustic insulation - in order to minimise internal reverberation and acoustic pollution towards the outside, in case of specific movement of historical units. When you reach the main entrance to the centre, the new nave opens up towards the offices through a large, glazed façade from top to bottom that allows you to observe the historical units from the outside, like a great heritage showcase. This façade disintegrates into a lower, irregular volume when it reaches the end of the unit, highlighting its access through a double pillar and revealing part of the inner face of the arched roof. This decomposed and lighter end of the main unit adapts kindlier to the set of elements of the main entrance to the centre and still allows a glimpse of the original workshop space from the street. In short, a large and forceful infrastructural intervention that strengthens the railway image of the centre by means of its extensive length and makes it possible to extend the useful life of one of the most unique sets of FGC.