Monday, May 27, 2019

I-75 DRAWBRIDGE! over Saginaw River in Zilwaukee, MI

1960 Drawbridge: (Bridge Hunter)
1987 High Bridge: (Bridge Hunter; Satellite)

Chris Childes shared
Eric Simandl Some congressman had a cousin in the drawbridge business. They weren't supposed to be on Interstate Highways.

Up North Voice posted
Up North Voice You would think twice if you knew how had they botched the construction of the new one
Joe Newcomb Sr. Up North Voice I remember. They built from both end and when they met in the middle they were way off.
Joe Newcomb Sr. Justin Gates Google Zilwaukee Bridge accident. During holidays and deer season with the original draw bridge traffic would be backed up for 30-40 miles while ships went through.
Todd Kraemer They finished the new bridge just in time to not need to send ore up to Saginaw foundry....closed...
Shelley Letts Hart Todd Kraemer actually the foundry is still open and flourishing. What did change was the delivery of raw material from barge to truck. Still, I think most of us will agree the “new” bridge facilitates better traffic flow.
Christine Rousseau I worked at Farm Bureau with Michigan Elevator next door. The bridge opened for those huge ships to come to us! Grain and supplies. Ships from Russia and China I believe. Some of their sailors would come into our retail store for gloves and rope, etc. They were smelly....lol
[I presume this is the elevator.]

MichiganHighways
The bridge was only 150 feet wide and several ships actually hit the bridge, causing damage and additional tie-ups on the freeway as well. To top it off, shipping traffic actually quadrupled in the years after the bridge was completed and the back-ups on the freeway reached three to four hours in duration and often up to 30 miles in length. The worst back-ups, of course, occurred during major holiday weekends and during the fall hunting season.
As one can image, there were a lot of rear-end accidents. [MDOT via report2]

The new bridge has a vertical clearance of 125' to accommodate salties from the St. Lawrence Seaway. [MDOT via report2] That height would explain why I'm reading comments about people being scared to use the bridge. It did make a list of dangerous roads.
Photo taken by Richard Doody in November 1983 via Bridge Hunter

In April 2008, a scheduled $3.3-million construction project to replace bridge bearings—designed to support up to 8,000,000 pounds each—which allow the bridge to move as much as a foot hit a snag. Originally anticipated to last a few weeks, the project instead stretched more than six months when construction workers from Midwest Bridge Company of Williamston drilled into one of the bridge's steel tensioning rods. Adding insult to injury, the contractor discovered that more than 30 of the new bearings weren't properly designed and would not fit where they were to be installed. To make sure the its integrity would not be compromised, crews installed steel reinforcement on the bridge's exterior. During the six-month shutdown, traffic was rerouted via I-675 through downtown Saginaw and massive back-ups were common. Traffic began using the Zilwaukee Bridge again on October 1, 2008.
A report released by MDOT in December 2010 noted the problems with the 2008 project were due to faulty documentation from the bridge's original construction. "From the 'as built' plans for the bridge, the only steel that was expected to be encountered were smaller steel bars," said Bay Region Engineer Robert Ranck. "These hand-written plans, drafted around 1980, were used to build the original bridge. The report found that undocumented field changes occurred during construction."
[Another repair] project ran from April 2013 through 2015. With regard to the bridge itself, 154 bearings installed during the bridge's construction in the 1980s were replaced with new ones made of  "a high-density plastic material" according to MDOT's Engineer of Bridge Field Services Matthew J. Chynoweth. [The original bearings were made with "stainless steel, neoprene and teflon" [MDOT via report4]] The bearings—designed to support up to 8 million pounds each—require replacement because of normal wear and tear since the bridge's opening in 1987.  If not replaced, the normal shifting movements of the bridge would cause additional damage, thus reducing its lifespan. Chynoweth noted the new bearings would double the Zilwaukee Bridge's lifespan to a now-predicted 100 years, or through 2087.
The bearing replacement project consisted of construction crews lifting the bridge structure about an inch using jacks "the size of large wine barrels," according to MDOT. Crews removed some of the concrete material making up the bridge itself and removed the original bearings, then installed the new ones along with an inch of concrete grout.
To replace the worn out expansion bearings, they needed to lift the superstructure off the substructure at every pier and expansion joint location, which is 75 times. Some of the lifts are over 17,000,000 pounds. [TCtimes, paycount]

MDOT via report4
When the 940', 1700-ton launching girder is over a pier, the expansion joint is immobilized using a block of high-strength concrete. On Aug 28, 1982, while a concrete segment was being transported, the immobilization block for span 11 was crushed, fractured the pier's footing, and the span tilted. [MDOT via report4] They were able to build new pilings and a footing and salvage the pier columns and the span. [MDOT via report5]

MDOT via report7


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