Ambassador Bridge
Bridge Documented: July 27, 2003
Visit the Official Page For This Bridge
| Key Facts |
| Bridge Name | Facility Carried / Feature Intersected | Location | Structure Type | Construction Date / Builder or Contractor |
| Ambassador Bridge | I-75 Ramp / KH-3 Over Detroit River | Detroit and Windsor: Wayne County, Michigan and Essex County, Ontario | Metal Pony Truss Stiffening Cable Suspension, Stationary | 1929 By: McClintic-Marshall Company of Pittsburgh, Pennsylvania |
| Technical Facts |
| Structure Length (Including Approach Spans) | Structure Length (Excluding Approach Spans) | Roadway Width |
| 9602 Feet / 1.82 Miles (2926.7 Meters / 2.93 Kilometers) | 1850 Feet (563.9 Meters) | 55 Feet (16.8 Meters) |
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. The bridge features attractive pony truss stiffening. Deck plate girder and deck truss spans provide an approach. The bridge is unusual because the section of bridge between the anchorages and the main towers is not suspended. Note the lack of suspender cables. The bridge members and towers are painted an attractive aqua color, while the cables are white. The bridge was apparently painted black for many years. The towers feature a lattice-like design, and feature the name of the bridge mounted on top of them.
Finally, another unusual thing to note is that the bridge is privately owned and operated. Neither MDOT nor the MTO own the bridge. Wayne County has another independently owned bridge, which is the Grosse Ile Toll Bridge. The Ambassador Bridge Company has talked about constructing a cable-stayed bridge next to the suspension bridge. To build an ugly cable-stayed bridge next to this beautiful suspension bridge would ruin the Detroit skyline. If a new span is needed, Historic Bridges of Michigan and Elsewhere recommends building a suspension bridge that resembles the existing bridge, or build a second tunnel under the river.
Information and Findings From MDOT
The Ambassador Bridge connects the United States and Canada by spanning
the Detroit River. It is one of only two suspension bridges built in
Michigan and at the time it was completed, was the longest suspension
bridge in the world, extending a total of 9,602 feet with approaches.
Construction began on May 7, 1927 and was well on its way when it was
discovered that there was considerable breaking of the cable wires in
the Mount Hope suspension bridge in Rhode Island, where the
McClintic-Marshall Company was using the same heat-treated wires that
the design for the Ambassador Bridge called for. Work on the Ambassador
Bridge was suspended on March 5, 1929 and it was decided to replace all
of the heat-treated wire with cold drawn wire. This was a major
endeavor, since the main cables were already in place and much of the
center span had already been completed, including the stiffening
trusses. The main span was dismantled by lowering the stiffening
trusses, floor beams, and suspended steel onto barges in the river. The
new cables were then erected, and finally, the suspended span steel was
replaced. The bridge was opened to traffic on November 15, 1929, nine
months ahead of its scheduled opening despite these modifications. |
