In general, underground trains are programmed to run automatically. Ideally, computerized equipment and electronic circuits do everything themselves, accelerating and stopping trains, opening and closing doors, controlling the time between trains, and so on. This, of course, in theory, because in practice passengers hold the doors and cause delays, the rain makes trains slow down in open-air stretches and accidents happen. Therefore, man needs to interfere in the functioning — or at least keep an eye out to see if everything is going well.
In the São Paulo metro, for example, the essential sector is the Operational Control Center (CCO), an office where traffic controllers monitor all underground traffic, sending electrical impulses through the wiring to control the coming and going. of the trains — As you know, the São Paulo metro is powered by electricity.
Other teams are specially trained for emergency situations. When a blackout occurs, for example, trains stop and have to be evacuated. At the time of a blackout, the drivers themselves coordinate the abandonment of the wagons. Passengers exit trains by walking through the tunnels to the nearest station, on purpose-built side walkways.
Automatic pilot
In São Paulo, the train network is designed to work without human interference
LUXURY RESERVATION
Each subway train in São Paulo has a driver. However, he is there more to check that everything is running smoothly than to operate the train. When the ideal automatism does not work, then, yes, he can command the operation, using a lever that alternates the automatic, semi-automatic and manual modes
VITAL ENERGY
In cities where the subway runs on electricity, the secret of movement is the so-called third rail: through it pass the 750 volts of voltage that energize the trains. Through a piece of metal, the wagons receive the energy that turns the engines. To prevent any unfortunate person from touching the rail and turning into a barbecue, the third rail is on the opposite side of the platform.
FRICTION AND SAND
Subway brakes run on compressed air. But on the surface stretches, when the friction between the wheel and the rail decreases because of the rain, an emergency system comes into play that throws sand on the rail, increasing friction and helping to hold the wagons
BIG BROTHER
Under ideal conditions, the São Paulo subway operates automatically, without human interference. To check that everything is right, a group of operators controls train traffic at the Operational Control Center (CCO). As the responsibility is great, the CCO is a very quiet place and each controller’s work shift does not exceed six hours a day
HOT SCREEN
This monitor is the main working tool for traffic controllers. It shows the status of the entire line, indicating which trains are moving, which are stopped, and the average time between them. With this information, controllers can accelerate, stop or divert a train when necessary.
MAXIMUM SPEED
Each subway car has two engines (with 170 hp each) that work with the electrical energy sent by the third rail. The engines drive the wagon’s eight wheels and can make the composition reach 100 km/h. However, for safety reasons, the maximum speed used on the São Paulo subway is 87 km/h, reached between the most distant stations.
MILLIMETRIC STOP
Stopping at the station is also automatic. For it to occur in the right place, the third rail sends electrical impulses that reduce the speed of the engine, causing the train to always stop at the same point, with a maximum error of centimeters. Along the line, control boxes next to the third track send impulses for the train to speed up or slow down.