Owner: Fort Lewis, U.S. Army, Dept. of Defense
Architect: Jeff Foster, GGLO
President: John Hennessy
Vice President: Bryan Diloreto
Demo Project Manager: Jeremy Knapman
Superintendent: Jim Moehrle
Abatement Project Manager: Ryan Supplee
ABC member involved in the project:
United Rentals, Inc.
Taking down four structurally compromised stacks, some as high as 180-feet, in close proximity to both highly combustible materials and functioning buildings required significant project and safety planning and substantial engineering.
The Fort Lewis Stacks project started with the collaboration of Nuprecon and engineering experts to design a safe and innovative solution to remove the two rusting steel stacks and two breached concrete stacks. The ultimate answer was to use a series of custom developed, self supporting, crane “track” systems equipped with motorized scaffolding that ran the height of the stacks.
The first two stacks, fabricated out of now-rusting steel, were 60-feet and 120-feet high. It was the structurally compromised state of these stacks that mandated an innovative solution, because their weakened state eliminated the possibility of lowering them down to the ground with a crane. Worse yet, both stacks were sandwiched between 13 gas lines and a 10,000-gallon fuel tank feeding the active facility – live boiler plants, et al. Methodically and safely Nuprecon personnel demolished the structures.
The final two stacks were fabricated out of concrete over 180-ft high, which tapered in thickness from 16-ft. at the bottom to five inches at the top. While these two stacks used a similar solution, they had additional complexities. First, due to their diameter and height, an additional vertical support track was required.
The volume of material generated during the demolition of the concrete stacks was much higher, requiring additional safety precautions. Using the stack itself as a debris-shaft, Nuprecon cut and structurally supported a small hole in the base of each shaft, which was in the basement of its host building, for debris load-out.
Nuprecon completed this Department of Defense project without a single safety incident and on budget.