Multiple independent braking systems and adequate maintenance.
A single failure may cause the escalator to stop working, but it takes 3 failures in a row to make it catastrophic. Regular maintenance catches this failures before 3 in a row can occur.
Multiple independent braking systems and adequate maintenance.
A single failure may cause the escalator to stop working, but it takes 3 failures in a row to make it catastrophic. Regular maintenance catches this failures before 3 in a row can occur.