The ongoing multi-year transformation of the historic Tiffany flagship on Fifth Ave and 57th Street reached a pivotal milestone with a rare technical maneuver: a crane lifting a crane onto the rooftop.

The setup was ambitious, as the planning stage for this mobile crane lift took approximately nine months. Three engineers were involved, with Mclaren Engineering Group creating the initial drawings, the engineer of record WSP performing a loads-imposed review to ensure the existing structure could support the design and a third-party engineer completing a peer review before NYCDOB Cranes and Derricks.

On the day of the event, a licensed master rigger oversaw the delicate process, which lasted about 30 minutes and required three cranes to complete. A giant 105-ton Liebherr LTM1500 crane, with help from a Tadano 450 crane and eight large trucks serving as counterweights, lifted a mobile LTM1130 crane weighing approximately 66 tons seven stories.

This unique feat has occurred in New York City only three times before — at 787 11th Avenue four years ago, at the New York Public Library two years ago and, most recently, at New York’s LaGuardia Airport.

The lifting of the crane onto the flagship rooftop marked a much-anticipated new phase in the building’s renovation, which began in January 2020. The crane facilitates the building of the uppermost volume of the Tiffany-led project in partnership with OMA. The top stories of the structure, surrounded by a curtain of undulating glass, will house an exhibition, event and client-centric space with an outdoor terrace offering breathtaking views of Central Park.

The need for multiple cranes is a result of the building’s position. It is landlocked between two soaring structures, making vertical expansion an extreme engineering challenge. On one side stands Trump Tower (with its requisite Secret Service surveillance and complicated permit requirements), and on the other The Tiffany Flagship Next Door at 6 East 57th Street, which currently serves as Tiffany’s New York City Flagship until the transformation of 727 Fifth Avenue is complete.

Construction on the architectural marvel that has served as the cornerstone of Manhattan’s most fashionable shopping district since 1940 is scheduled to be completed in spring 2022.