Ballast reprofiling
Introduction
The maintenance of the quality of the road - which allows the safety and comfort of circulation - is carried out today with heavy machinery, which restores the geometric parameters to their theoretical values. For some decades now, said maintenance, as well as the laying of railway infrastructure, have been highly mechanized operations that entail great complexity, since they must serve so that modern trains can perform their services safely and comfortably.
The beginnings: manual track maintenance
At the beginning of the railway, the quality requirements for the track were quite low, a consequence of the limited speeds of those first trains. The basic concern was safety, mainly to avoid derailments, which were very numerous: the only maintenance consisted of the timely correction of those defects that compromised the circulation of vehicles. The progressive increase in speeds caused comfort criteria, which were much more demanding, to be taken into consideration.[1] This gave rise to the birth of the periodic review, which consisted of action on all the constituent elements of the superstructure at fixed time intervals, in order to restore the original parameters. Over time, the different actions were systematized, giving rise to the so-called methodical conservation that, with predetermined cycles, contemplates the review of all the elements that make up the rolling path.
Until the middle of the last century, all track maintenance tasks were carried out manually: leveling, alignment, tamping, profiling and renewal used a large amount of human resources, then very economical, in most cases working in difficult conditions. Manual tasks that were not merely punctual were since then progressively replaced by heavy machinery.
The first machines on the Spanish broad gauge railway network
The first heavy machinery acquired by Renfe date back to 1956: they were modest tampers that did not have any leveling or alignment mechanism. They were built by the Swiss company MATISA, the name by which this type of vehicle will be popularly known from then on. In 1964, a series capable of automatically leveling the track was acquired, as well as the first ballast stripping-screening machines. In 1970 the hegemony of the MATISA company was broken with the acquisition of the first machines from the Austrian company PLASSER. Until then, the machines carried out their work in isolation, according to the state of the network. Starting in the early 70s, High Performance Groups were created, assigned to certain geographical areas.