Ambassador Bridge

Construction had actually begun a month and a half before the referendum. Congress had ruled that construction would have to begin by May 12, 1927, or the bridge franchise would expire. Hoping that Congress would regard boring operations as a meaningful start of construction, Bower staged ceremonies May 7 with Austin's 16-year-old daughter Helen driving the first boring stake into the ground to determine the depth of the bedrock.

Helen Austin, driving the first boring stake into the ground

Helen Austin, the first woman to walk across the Detroit River

The general contract for construction was signed July 20, 1927, and made operative August 16. McClintic-Marshal was allowed until August 16, 1930, to complete the job. If it was not done by that date, the engineering firm would be liable for interest on the securities until the bridge began producing income. If McClintic-Marshall finished the job in advance of the deadline, they would be entitled to half the revenues between the date the bridge opened and April 16, 1930. Just over two years later - on November 11, 1929 - the Ambassador Bridge was ready for operation. McClintic-Marshall had brought the job in one percent

When the Ambassador Bridge opened for traffic four days later, its almost 21,000 tons of steel rose at never more than a five percent grade to an apex of 152 feet above the swift current of the Detroit River. Its 1,850-foot center span made it the longest suspension bridge in the world. Its total length was 7,490 feet, with the U.S. and Canadian terminals 1 3/4 miles apart. The roadway was 47 feet wide with an eight-foot-wide sidewalk on the west side. The twin silicon steel towers that rose majestically 386 feet above the ground were built on concrete piers resting on bedrock 115 feet below the surface.

Close to two miles of cable within cable within cable - 37 strands, each as big around as a strong man's biceps, each composed of 218 individual sinews of cold drawn, galvanized steel - had been erected. The main cables suspended between its two towers were fastened to massive concrete anchorages 22 1/2 feet wide and 100 feet long, sunk into bedrock 105 feet down. The cables - but not these cables - were also the most dramatic story of the construction.

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 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.