Survivors’ Stairway May Survive

The Survivors’ Stairway, previously thought to be threatened, may be preserved in some way after all:

There is an extremely slim chance that the staircase will be left in place while the foundations for Tower 2 are excavated around it. There is a greater chance that the 21-foot-high, 64-foot-long staircase will be moved in its entirety, perhaps ending up in another location at ground zero, perhaps returning to the Tower 2 site.

“If the decision is that it does stay there, that’s a challenge,” Lord Foster said. “We’ll work with that challenge.”

Robert Silman of Robert Silman Associates, an engineer who is preparing cost estimates for the New York Landmarks Conservancy, a preservation group, said either approach would be feasible.

To keep the staircase on site during construction, it would have to be turned into a 91-foot-high mesa in the middle of an excavation pit, stabilized by X-shaped bracing. Mr. Silman said the job of holding up the staircase would be made somewhat easier because one existing support already extended to bedrock.

To move the whole staircase, Mr. Silman said, three layers of steel beams could be inserted below the structure to create both a platform and a track system. The structure could be cut away from its surroundings by water jets, jacked up, rolled out along the track beams and then lowered onto enormous dollies.

A more likely outcome — at least at this moment — is that the surface of the staircase, which still has original stone treads in its upper flight, would be cut apart from the big bulkhead that contains it, divided into sections for easier transportation and storage, then reassembled later as a memorial artifact.