CHICAGO | Salesforce Tower | 850 FT | 60 FLOORS

[Fvn]

FWIW the core was actually jumped this morning, but you're right, for the better part of about 3 weeks it didn't move. There could be numerous reasons as to why it stopped, but I doubt it has anything to do with last-second design changes. Also, the current lead times mean that making last-second design changes is even more headache-inducing than they usually are especially with a project of this size.

It could have something to do with the core being limited as to how tall it can free stand above the finished steel (fully bolted/welded, not just set) with a crane in it; especially when it's as skinny as it is now is.