Electric Traction Articles
In an article in Nord Milano magazine, which we show here in the images below, the operation of the Novate Milanese substation is described in a technical yet simple way. The following is an extract: “The 23,000 volt alternating current enters the room located above the rear bay, and from there it descends into transformers which lower it to an appropriate voltage. From there it passes through underground cables to the front bay and enters the rectifiers which transform it into a 3000 V direct current.
From there it is then sent out onto the line. The transformers are immersed in oil and are cooled with an air current. In order to achieve this, each of the transformer cells is equipped with a special vent which acts as an aspirator, underneath which there is a tank to collect any oil that needs removing from the transformer. This tank communicates directly with the exterior and serves not only to drain the oil but also to ensure the flow of cool air”.
Gallery
The subject of this article from Nord Milano magazine from May 1930 is the substation at Novate: an incident on 31 March of the same year had caused the suspension of trains running on the Milano-Saronno and Milano-Meda lines 
Oil from one of the substation’s transformers had caught fire, and the flames destroyed the upper part of the building in which all the equipment for receiving the high-voltage current was housed 
Hence the shutdown of the vehicles which suddenly found themselves without power. But this episode did not diminish faith in the new technology: rather, it became an incentive to discuss future improvements, and, with pride, the complex and ingenious operation of the substation itself. 
Another article from Nord Milano magazine from 1929 enthusiastically describes the start of electrification work by Ferrovie Nord 
The second part of the article, featuring an excellent photograph of the newly opened Novate substation