The Mayrit tunnel boring machine doubles its performance and arrives in Palos de la Frontera weeks in advance

The Mayrit tunnel boring machine arrived last Friday in Palos de la Frontera several weeks early because the rates at which it is excavating the bowels of the capital practically double those that the engineers had contemplated before its activation. From the theoretical performance of 15 meters per day, it has gone to an average of 30 per day with peaks that have reached 40.

If in the next sections of the project, from Palos de la Frontera to Atocha and from this point to Conde de Casal, the record drilling speed is maintained, the completion of the future tunnel of line 11 (L11) of the Madrid Metro would surely be in the first quarter of 2027, although the inauguration of the section would still take several months, or even a year. Because the estimated start-up date of the Plaza Elíptica-Conde de Casal route remains unchanged at a time no earlier than November 2027 or well into 2028.

The reason is that the tunnel carried out by Mayrit is only part of a project that is much more complex and large in scope and takes different times because it involves actions of a very different nature. From the conditioning of the subway itself (laying of tracks and catenary, assembly of signage...) to the excavation of five stations and their subsequent provision (elevators, escalators...) to the construction of a dozen ventilation shafts along the route: all are 'pieces' of a larger puzzle that is the construction of the L11 between Plaza Elíptica and Conde de Casal.

There are those who consider that L11 is seven major works in one: the tunnel that is being carried out with pick and shovel between Comillas and Plaza Elíptica, the subway that Mayrit is undertaking and five other interventions, one for each station in operation. Each action has its calendar and has its particularities, characteristics that mean that, in any case, they cannot benefit from the two circumstances that have led to the good performance of the tunnel boring machine: its exceptional technical performance and the little resistance that the capital's soils have shown it.

It is due to this impossibility of cutting entire weeks from the work schedule that the works on L11 may be extended for up to one more year - if its premiere is finally scheduled for early 2028 - once the tunnel boring machine has reached the point in the Hortaleza district, a loop of the M-30 located about 350 meters from Conde de Casal, from which it will be extracted from the underground. Only the progress on site over the next few months will be able to clear up the question of when the new kilometers of metro that this project represents will come into service.