[chris08876]

Glaziers, in harnesses attached to an enclosed aluminum rig, are replacing all 480 windows in the tower’s mooring mast

Suspended more than 1,000 feet above Midtown Manhattan, workmen are giving a painstaking face-lift to one of the world’s most storied skyscrapers: the Empire State Building.

Glaziers, in harnesses attached to an enclosed aluminum rig, toil in the darkness of early mornings to replace all 480 windows in the tower’s mooring mast, which original developers claimed was designed to dock airships but became famous for being King Kong’s perch.

The goal is simple: to refurbish and protect the 200-foot-high, rocket-shaped pinnacle from the elements. The glass panes shield LED lights that are part of the massive system used for the building’s light shows. Some of the windows have been patched and many have been around since the building opened in 1931.

But the process to seal the docking station, one of the last phases of a bottom-to-top restoration, hasn’t been easy. The construction company Skanska USA and building owner Empire State Realty Trust Inc. began planning the work in February 2014.

“Now that we have rejuvenated everything from its infrastructure, its energy efficiency [and] its tenant mix, we had to get to the mooring mast,” said Anthony E. Malkin, chief executive of the Empire State Realty Trust, the public real-estate investment trust that owns the skyscraper. “And it was a very complicated process to get there.”

One of the construction company’s challenges was just figuring out how to get workers and materials into place in a building that is occupied with office tenants and has an observation deck that is open until 2 a.m. “That was 90% of the battle,” said Scott Seydor, Skanska project manager.

A team that included architects, engineers, historic preservationists, a construction manager and experts in glazing, waterproofing, safety, metallurgy and scaffolding took part in the planning process. They had to get an understanding of how the windows were originally installed—from the outside—and how to get crews in place to do the work.

The group had to get the glass panes custom made. The members studied scaffolding options, ultimately choosing suspended scaffolding that also had to be custom designed. And the group had to get approvals from the city’s Department of Buildings as well as the Landmarks Preservation Commission.

The weekday work replacing windows, which started in July and should be completed in November, takes place under tight time restrictions. Before the 2 a.m. closing of the observation decks, crews from subcontractor Kilroy Architectural Windows begin loading and tethering tools and supplies onto four scaffolds—one on each side of the building.

The glaziers are in action from 2 to 7 a.m. but have to stop if wind speeds exceed 25 mph. Before they can start their work, the three-man crews have to get to up there, and it takes about 10 minutes for the rig to travel from the 90th floor, four stories above the observatory deck, to the 102nd floor near the top of the mooring mast. They have to work at a steady clip to replace eight panels each night.

=========================
http://www.wsj.com/articles/raising-...ng-1440979749/