What are pros and cons of a vacuum brake system compared to air brake.?!
Both types rely on air pressure. In the case of vacuum brakes, it is the pressure of the atmosphere, around 14.8 psi at sea level. This meant that the only way to increase the braking force from a vacuum brake cylinder is to increase its diameter. Air brakes on the other hand can have much smaller cylinders as they do not have an upper pressure constraint. Smaller components weigh less and simplify the design layout of the underbody parts of rolling stock. Air brakes have proved their effectiveness and reliability over the many decades since their introduction. If this question was prompted by the recent accident in Quebec, it should be noted that both air and vacuum brakes become ineffective on an unattended stationary train after a while due to leakage, (loss of pressure or vacuum).
