Operating machines, also known as “yellow machines“, are used for the maintenance of the railway infrastructure. Although there is no regulatory reference that imposes this color scheme, these machines must be visible and recognizable from a long distance; hence, the yellow.

Traditionally, this color is believed to be the best for this purpose and is associated, in other sectors as well, with a warning signal. Red, on the other hand, is associated with a danger sign (for example, just think that in the past there was an Italian technical prescription that required the presence of a red panel on the front of the vehicle for all locomotives circulating in Italy).

Paddington Station – Elisabeth Line – London. Source:

Historically, for example, even the trains of the Elisabeth Line in London had to be equipped with a yellow front panel to increase the visibility of the vehicle. In fact, starting from the 50s of the last century, the first electric and diesel trains were born and they were much more quieter than their steam predecessors. This standard has recently been superseded thanks to the development of new technologies in the field of lighting and, therefore, of the increasingly advanced headlights of the train. It is therefore the direct railway operators  who are currently responsible for making vehicles safe and must ensure that these are sufficiently visible.

Yellow machines are therefore vehicles that, like trains, travel on tracks and are used in many different applications; by way of example: grass cutting, construction of the catenary, tamping of the tracks, construction of new lines or renewal of existing ones; This last operation consists in the replacement of worn rails, an activity that, until the last century, was done by hand! (as you can see in numerous westerns).

Workers involved in the construction of a railway. Source:

Although they are little known, even among fans of the sector, they are essential and, like industrious bees, they work silently to ensure the efficiency and safety of railway lines.

Often these machines operate concurrently with other vehicles in service, in an almost totally automated way, and are subjected to stringent criteria of environmental respect (minimization of noise, dust and vibrations). It happens that they find themselves operating in the city center, in the presence of historic buildings, or in tunnels, with consequent logistical difficulties in the handling of machines and materials.

These are very complex vehicles. Suffice it to say that a renovating train, whose function is to replace worn rails and sleepers with new parts, is made up of: 1 locomotive, 10 transporter wagons, 1 renovating train, 1 pandrol clipping machine, cranes. And if this was not enough, following the renovating train there are profiling machines, tamping machines and a welder.

Plasser&Theurer tamping machine. Source:

The fleet of operating vehicles is very numerous: the machines authorized by RFI are currently more than 9,000 but further upgrades and investments are planned for new ones such as trailers, wagons / carriages, positioning machines, re-laying trains, locomotives and weeder trains.

And for this multitude of yellow cars, there are as many operators in the sector who have to interface with these trains every day.


Our mission is in fact to create the best conditions for interaction between person and machine, of any kind.

We design and manufacture driver desks around the driver, to facilitate driving operations and require minimal effort of the operator. The design and layout of the driving position are therefore conceived to “embrace” the human, who every day has to interact with a machine that combines the complexity of a railway vehicle with that of an operating machine.

We use cutting-edge technologies in order to meet high quality and reliability standards, in compliance with all the sector regulations, in order to create something innovative and that really improves the working conditions of train drivers around the world.

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See you next time,
Valentina Marrese