reconstruction under way
The Portsmouth piece of the new Memorial Bridge was placed on January 15th. I had been thinking about taking a day off to watch; unfortunately I missed the day before the event announcement only finding out about the placement as it was happening. The Kittery section is supposed to be put in place sometime in March and the center span is scheduled for June. I've signed up for email notification in the hopes that I find out about the lift section placement in enough time to (maybe) spend the day watching.
The new bridge is clean and has a very smooth look. I'm fascinated by the design elements. From the 21st Century Innovations page of the Memorial Bridge project web site:
THE FIRST OF ITS KIND IN THE WORLD, A GUSSETLESS BRIDGE
The new bridge design has eliminated the most vulnerable part of a truss – the gusset plate – that has historically been the cause of costly maintenance, repairs, and replacements. A gusset plate is a thick plate (sheet) of steel used to connect the various pieces of the bridge (or truss members) and kept in place with steel bolts. As the gusset plates corrode and weaken (and require costly retrofitting), as was the case with the 1922 Memorial Bridge, they compromise the strength of all the separate pieces.
The design team eliminated gusset plates entirely. Instead, the metal sections are all uniform in size so they fit together like puzzle pieces, through a process called splicing.
...
USE OF A METALIZED COATING
The steel portions of the new bridge will be finished with a metalized coating expected to last 40-50 years without requiring maintenance. The process utilizes an electric arc spray gun to apply molten zinc onto the surface of steel. Zinc provides the highest protection from corrosion and also keeps the look and feel of the new bridge in-line with the local U.S. Navy shipbuilding history.
from old to new
