Photo by Spiggycat.

A project to replace three escalators at the Bethesda Metro station is expected to take over two years.

According to Metro, each escalator will be replaced at a different time, with the work only able to take place overnight. “Rising 106 feet, the entrance escalators at Bethesda Station are the second longest in the Western Hemisphere (behind Wheaton Station), and replacing the units will be a much harder task that their initial construction,” the system said in a release.

The contractor, KONE, expects each escalator’s replacement to take around 42 weeks. That’s about two-and-a-half years total for the replacement of all three escalators. Metro says it’s looking for ways to shorten the timeline.

“Transit Police, emergency management, rail supervision and escalator technicians” will be at the station for the duration of the replacement. But Metro warns that, “in the event of a service disruption,” the station may need to be closed temporarily to avoid overcrowding.

According to DC Metro Metrics, the three escalators have a reliability rate over 87 percent.