Summary
Highlights
On October 23, 2018, an escalator at the Republica station in Rome malfunctioned, leading to 24 injuries. The escalator, overloaded by football fans, experienced a full cascade of safety system failures: the motor lost control, the main brake failed due to weakness, and the auxiliary brake was sabotaged with plastic straps. Investigators later found that error logs were disabled and maintenance records falsified, pointing to severe neglect and deliberate sabotage by the transit agency ATAC and its contractor Metro Roma.
The first escalator, 'The Continuous Elevator,' was invented by Jesse Reno in 1896 and was initially a theme park attraction at Coney Island. It was a 25-degree conveyor belt without steps, which people found precarious to walk on and unsettling to stand on. This early design highlighted the need for a mechanism that provided a flat surface for riders.
George Wheeler introduced the revolutionary design for modern escalators. His invention allowed each step to rotate freely and independently via a dual-track system, ensuring a flat surface for riders throughout the journey and enabling the steps to tuck away and flip at the top and bottom. This design solved the issues of previous 'revolving stairs' that made disembarking hazardous.
Wheeler's patent was later acquired by Charles Seeberger, who partnered with Otis Elevator Company to build the first commercial escalator, showcased at the 1900 Paris Exposition Universelle. Early escalators had smooth, flat stairs that disappeared under a wooden board, creating dangerous gaps where clothing and even children's feet could get caught. Initial solutions included a triangular shunt to direct riders, leading to the convention of standing on the right.
Modern escalators feature grooved steps that interlock with a comb plate at the top, preventing items from getting stuck and allowing safe forward disembarking. The addition of skirt brushes in 1982 addressed the problem of objects getting trapped in the side gaps of the escalator, further enhancing rider safety.
Inspired by Jesse Reno's early design, modern escalators have moving handrails. These handrails are designed to move about 2% faster than the steps when new to compensate for wear on the friction wheel that drives them. Furthermore, downward escalators utilize AC induction motors and regenerative braking, allowing them to generate electricity from the weight of passengers on busy days, effectively turning into generators and significantly improving power efficiency and inherent safety.
The investigation into the Rome accident revealed that the failures were not due to manufacturing defects but rather a pattern of negligence and falsification by maintenance contractors and transit authorities. This incident underscored that despite robust engineering, escalator safety ultimately relies on human responsibility and proper maintenance. Authorities arrested and suspended 11 individuals, including managers, for deliberately sabotaging safety features to avoid shutdowns, highlighting a 'human failure' rather than an 'engineering failure'.
When properly maintained, escalators are remarkably safe, designed to handle forces far beyond typical use. With 1.5 million escalators worldwide facilitating billions of trips annually, they are a vital form of transport. The video concludes by emphasizing that while technology is well-designed, human responsibility in maintaining these systems is paramount. It stresses the duty of care humans have towards each other to ensure safety, echoing Jesse Reno's initial problem-solving approach to a mundane challenge.