Monday, January 16, 2017

1928 Ambassador Bridge over Detroit River at Detroit, MI

(Official PageMDOTBridge HunterHistoric BridgesSatellite (has 199+ photos), Birds-Eye View)

Detroit Public Library Digital Collections

Curt Danielewicz shared Mike Murin's photo
Construction hasn't finished on the Ambassador Bridge the Deck hasn't been completed,,Showing the Train yard for the Fort Street Union Depot near the 6th Street Train Tower that controlled Train traffic to Union Depot..


Wabash boat yard on the Detroit River as well as the passenger car and locomotive servicing area of Detroit's Fort St Station.

Rodney D Zona Judging by the construction of the Ambassador Bridge, the shot above was taken in 1928, 1929 or 1930.

You can tell I favor railroad bridges. According to my labels, this is the first suspension bridge that I have written about.

Mike Russel photo from Bridge Hunter
Used under the terms of the GNU Free Documentation License.
Note how the roadbed curves up in the above photo so that it looks like it would end in a V. After they add the additional weight of the remaining roadbed, the cables should bend down so that the roadbed meets as a smooth curve.

Ambassador Reward Card
Ken Janeczko posted
Fearless - downbound past the Ambassador Bridge on Sunday afternoon.
[This is the posting that made me aware of this bridge.]
Once again, "being on the cutting edge of technology can make you bleed:"
The Changing of the Cables

The hissing of acetylene torches, the rasp of steel and the clatter of long lengths of cable being cut from the Ambassador Bridge to make room for stronger strands filled the air around the Bridge in the spring and early summer of 1929, just months before the Bridge would open. McClintic-Marshall had specified that the then-new heat-treated wire cables be used instead of the universally used cold drawn steel wire. The new heat-treated wire cables had been tested and found to have much higher tensile strength than the cold drawn steel wire used on the Brooklyn Bridge, for example, for 50 years.
These heat-treated wires had been woven strand by strand into the 37 component cables of each of the two massive main cables that would support the world's longest suspension bridge, and by mid-February of 1929, the suspenders, like steel harp strings, had been hung from the cables and work had begun to fasten the steel framework of the roadway to the weighted ends of these suspenders. Progress on the Detroit River span was a whole year ahead of schedule.
But the up mood on the Ambassador Bridge turned sharply downward when word reached Detroit on February 22 that a number of broken wires had been found in the cables of the even more nearly completed Mount Hope Bridge in Rhode Island. This bridge shared with the Ambassador Bridge the distinction of being the first to use heat-treated wire instead of cold drawn steel. It came to light that three broken strands had been found near the Bristol, Rhode Island anchorage of the Mount Hope Bridge as early as January of 1929. Subsequent inspection on the Detroit River project revealed a few under any other circumstances, not an alarming number of broken wires in the Ambassador Bridge's cables.
McClintic-Marshall, the same engineering firm that was building the Mount Hope Bridge, halted work on the Ambassador Bridge on March I and summoned a team of consultants from the Massachusetts Institute of Technology to examine the situation and report. Based on that report, McClintic-Marshall - with full concurrence of Joseph Bower decided to absorb the half-million-dollar expense of removing the cables over the Detroit River and replacing them with time-tested cold-drawn steel wire. When the torches began hissing and the cutters began lopping the enormous cables into manageable lengths and lowering them to the ground, it was thought the entire year that work crews had gained on their three-year contract was hopelessly wiped out. But the old cables were replaced with new in time to hang the roadway and open the bridge on November 11 - nine months ahead of schedule. [History]
It sounds like they tested for tensile strength but not brittleness and/or fatigue failure.

"Michigan has had the distinction of having twice built the longest suspension bridge in the world. The Ambassador Bridge, constructed in 1929, was the first, and the Mackinac Bridge was the second." [Historic Bridges]

It appears the bridge has four lanes with NO shoulders, but it has a pedestrian/bike walk. However, Historic Bridges reports that the pedestrian walk has been closed since 9/11/2001. This would be another example of bureaucrats, feeling that they must do something, allow the terrorists to win by negatively impacting our way of life with ineffective restrictions. What is a pedestrian going to do? Cut the cables with a bolt cutter? If someone wanted to bomb the bridge, they would put the bomb in a van rather than hand carry it. Historic Bridges says that vehicles are not searched until after they have crossed the bridge. "In addition, HistoricBridges.org has read reports of photographers in this park being harassed by Detroit International Bridge Company security guards (who patrol the lands bought up by the Detroit International Bridge Company around the bridge) even if the photographer is on public property, such as in the riverside park, and thus not in violation of any law." [Historic Bridges] This is another example that the person in charge of security is "overzealous."

The company that owns the Ambassador Bridge is proposing a new 6-lane-with-safety-shoulders, cable-stayed bridge to be built next to the current bridge. In the meantime, the governments are planning a much more appropriate cable stay bridge further downstream to directly connect I-94/I-75 with KH-401. This would keep heavy traffic off the city streets in Windsor. The bridge company's argument that a downtown bridge would bring more business to the downtown is totally bogus. When I have to drive through a big city, I try to plan to do it off hours and the last thing I'm going to do is stop in the big city. The "more business for downtown" argument indicates to me that they are grasping at straws as to why their bridge should be built rather than a beltway bridge. But the family that owns the bridge wants their golden goose to lay even bigger eggs. [The "related content" articles in MichiganRadio]

"The Project will retain the existing historic bridge for overflow traffic, use by bridge maintenance vehicles and special events.  " [SecondSpan]
Update: the family that owns this bridge is also the one that owns the Michigan Central Depot and allowed it to fall into disrepair.

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