To save us all the humiliation of putting our feet in our mouths if we’re ever lucky enough to visit the topic of today’s video, we offer the following public service announcement.
Though it can be spelled with “AC” or “AW”, as Michiganers are fond of pointing out, Mackinac is always pronounced with the AW sound at the end.
That said, the Mackinac Bridge is a massive 60-year-old suspension bridge spanning the Straits of Mackinac between Michigan’s Upper and Lower Peninsulas.
Part of Interstate 75, it connects Mackinaw City in the south with St. Ignace in the north, and sits near the junction of Lake Michigan to the west and Lake Huron to the east.
With a shoreline-to-shoreline length of just under 5 miles (4.995 miles or 8.038 km to be exact), “Big Mac” is the longest bridge of its kind in the Western Hemisphere.
In addition, at 3,800 feet (1,158 m) its main span is the third longest in the United States, and the 20th longest worldwide.
The Mackinac Bridge is often compared to other behemoths like California’s Golden Gate and San Francisco-Oakland Bay bridges, but though the former has a longer span between towers, it’s less than half as long from end to end.
Likewise, at nearly 8.5 miles long (13.6 km) the San Francisco–Oakland Bay Bridge is significantly longer, but it has an anchorage in the middle.
Though construction wasn’t completed until the summer of 1957, the idea took root more than 70 years before when industry, tourism and population were beginning to boom in Michigan.
However before the bridge was built the only ways to travel between peninsulas were circuitous road routes and state-operated ferries, the latter of which featured long wait times, hair-raising journeys during inclement weather, and only seasonal service.
The word Mackinac is a shortened English version of a longer and more difficult to pronounce Native American term that loosely translates into Great Turtle.
Historians and linguists disagree about the word’s origins, but it may refer to the shape of nearby Mackinac Island.
Whatever the case, thanks to abundant fish and game and a myriad of navigable waterways, the region supported a number of thriving Native American groups that often congregated in and around Mackinac to trade and interact socially.
Not surprisingly however, when the first settlers of European descent began showing up in the late 1600s, the region’s vast forest and mineral resources became the objects of great desire, though it wouldn’t be until a century later when exploitation began on a large scale.
Ultimately more settlers followed, cities and towns were established, and later railways were built.
Trucks and automobiles eventually burst onto the scene too, and as early as the first decade of the 20th century the demand for a safe, speedy, vehicle-friendly route between the two peninsulas grew.
As a result, Michigan established a ferry service between Mackinaw City and St. Ignace in 1923, and within a few years the fleet consisted of nine boats that collectively carried thousands of vehicles back and forth every day.
However, with each passing year as automobiles became more affordable for working-class families, the ferries had a harder and harder time keeping up, and it became apparent that a more efficient and inexpensive solution was needed.
On a per-car basis, ferries were exorbitantly costly to operate, and during the winter months they shut down altogether.
With the writing on the wall, in 1928 Governor Fred W. Green ordered the state’s Department of Transportation to look into whether a bridge was feasible.
The following year they concluded that it was, but that all told planning, engineering and construction would probably take the better part of a decade and cost about $30 million, or about 400 million USD today.
But as is often the case, initial projections significantly underestimated the overall cost.
In the mid-1880s a shopkeeper in St. Ignace published a newspaper article in which he detailed his vision for a bridge that might one day span the Straits of Mackinac.
At about the same time Michigan’s Legislature was debating the issue, and uber-rich railroad tycoon Cornelius Vanderbilt II proposed a similar bridge in a meeting with business associates on Mackinac Island.
The wheels were turning and everyone agreed that a new bridge would increase commerce and tourism and raise the living standards of countless families in the area.
That said, the scheme ultimately languished on the proverbial back burner until the ‘20s when the state’s highway commissioner reviewed various proposals that included everything from floating tunnels and suspension bridges to a mishmash of causeways running between islands.
At least theoretically, each would connect the two sides of Michigan permanently, but it wouldn’t be until 1934 until the Legislature took action by creating the Mackinac Straits Bridge Authority.
In the early going the Authority was tasked with figuring out which design was the most promising and how the project would be funded.
Sadly, the nation was still reeling from the ravages of the Great Depression, and though the federal government was doling out money for infrastructure projects on an unprecedented scale, the bridge just wasn’t a priority despite support from local business leaders, state politicians, the US Corps of Engineers and President Franklin Delano Roosevelt himself.
But though federal funding never materialized, between 1936 and 1940 the Bridge Authority received and reviewed additional proposals and commissioned various studies to determine the best route and economic impact of the proposed bridge.
Initially, it was envisioned that the bridge would consist of a 3-lane roadway with a rail line slung underneath, the latter of which would’ve made Cornelius Vanderbilt II jump for joy, had he not been deceased.
The route chosen allowed anchorage piers to be sunk in relatively shallow water, which would reduce cost and speed construction.
On the downside, the bottleneck between the two Great Lakes was subject to high winds, ocean-like waves and huge masses of ice that would put tremendous sustained pressure on bridge elements.
Between 1939 and 1941, though funding hadn’t been secured, a 4,000+ foot (1,219 m) concrete causeway was built from the north, but with the outbreak of the Second World War work has halted while the country’s industries and laborers turned their attentions to more pressing matters.
Though it’d pushed the project forward as much as could be expected under the circumstances, the Mackinac Straits Bridge Authority was abolished in 1947, but three years later another – the Mackinac Bridge Authority – was created.
By then motorists typically had to wait five hours for ferry service not including the trip itself, and collectively the boats were only capable of transporting about 500 vehicles per hour, though the proposed bridge would be able to accomodate more than four times as many.
Finally realizing that they’d never get money from the federal government, in early 1951 the state legislature authorized the sale of $85 million (about 700 million USD today) in bonds to fund bridge construction
However, thanks to one of the worst bond markets in history, the Korean War, scarce buyers and difficulty finding an underwriter, the bond issuance was delayed for nearly two more years.
Design & Construction
In the early ‘50s renowned New York civil engineer David B. Steinman was hired to design the bridge, and much of his inspiration came from the Brooklyn Bridge that he saw every day growing up.
Steinman’s design was also influenced by lessons learned after the catastrophic failure of the Tacoma Narrows bridge in Washington state in 1940.
After the disaster, which was caused by a deadly combination of high winds and inherent engineering flaws, Steinman published a lengthy critique of the bridge’s design and put forth a number of solutions to prevent similar tragedies in the future.
Namely, his bridge would include stiffer and deeper-set trusses to support the deck, numerous open areas through which wind from all directions could pass, and a deck shaped like an airfoil to cut through the air efficiently instead of acting like a giant sail.
Together, these revolutionary elements allowed the bridge to withstand winds up to 150 miles per hour (240 km/h).
By the end of 1953 funding had been secured, Steinman’s design had been finalized, cost estimates had been completed, and construction contracts had been awarded.
US Steel Corporation’s American Bridge Division would erect the bridge, while the Merritt-Chapman and Scott Corporation of New York would handle the site and substructure work.
Construction officially got underway in early May of 1954 using the previously built causeway as a starting point.
Next, caissons were constructed, floated into position and sunk to provide solid foundations on which the two immense towers would be anchored.
Once these were in place, the dangerous, slow and tedious work of stretching the cables and erecting the roadbeds by way of creeper derricks began.
Larger truss sections were assembled offsite, transported by barge to the bridge and raised into place.
All told, more than 3,500 workers toiled on the bridge, and 7,000 more labored at quarries, steel mills and machine shops all over the country.
The blueprints and structural designs totalled nearly 1 million, and the bridge was built with –
- 3.6 million tons of steel
- 931,000 tons of concrete
- 4.8 million rivets
- 2,000 miles of woven cable made up of 42,000 miles (68,000 km) of individual wires
At midspan the roadway was 200 feet (61 m) high, and the tallest towers rose more than 550 feet (168 m) over the water below
Accidents, Fatalities and other Incidents
All told just five workers died during construction, making the project one of the century’s safest relative to scope and overall cost.
The first fatality occurred in mid-September of 1954 when 46-year-old diver Frank Pepper ascended too quickly from nearly 150 feet (45.7 m), after which he died from the bends.
The following month 26-year-old James LeSarge fell 40 feet into a partially completed concrete structure, sustaining a fatal head injury against exposed steel beams on the way down.
Two weeks later a welder fell into the water and drowned after experiencing what witnesses claimed was a heart attack.
Then in June of 1956 two men died on their first day on the job after a catwalk collapse near the north tower.
All five men are memorialized on a plaque at a park near the north end, but despite persistent rumors, none of them are interred in the bridge’s concrete structures.
Since then the only other worker to perish on the bridge was Daniel Doyle who fell from scaffolding in early August of 1997.
Doyle actually survived the relatively short 70-foot (21.3 m) fall, only to die from hypothermia in the chilly 50 °F (10 °C) water shortly thereafter.
The following day his body was recovered in 100 feet (30.4 m) of water nearby.
In addition, at least two vehicles have plummeted over the sides of the bridge.
In September of 1989, Leslie Ann Pluhar died when her car plunged over the short guardrail.
Though high wind gusts were originally blamed, this finding wasn’t supported by local meteorological measurements taken at the time.
Later investigations determined that she’d simply been driving recklessly and lost control.
Then in March of 1997, Richard Alan Daraban drove his car over the edge in an apparent suicide.
The bridge was also the site of at least two aircraft incidents, the first of which was among the world’s most epic aviation stunts, while the second was a fatal disaster.
In late April of 1959, Strategic Air Command Captain John S. Lappo flew his six-engine 100,000+ pound (45,360 km) Boeing B-47 Stratojet beneath the bridge, after which, big shocker, he was court-martialed.
In mid-September of 1970 during a particularly heavy fog, a small private plane with three US Marine Reserve officers onboard slammed into one of the bridge’s suspension cables.
The impact sheared both wings from the fuselage, after which the plane dropped like a stone into the water below, killing all three men.
Since the Mackinac Bridge isn’t open to pedestrians, jumping suicides are rare, though there have been more than a dozen in the past few decades alone.
All told, construction costs topped 700 million USD when inflation is accounted for.
These days the toll is $2 per axle for passenger vehicles, and $5 per axle for RVs and commercial vehicles.
Maintenance is ongoing, and on average it takes about seven years to paint the bridge from top to bottom and end to end, after which the process is immediately begun again.
By 2005 about 11,700 vehicles per day traveled over the bridge, and two years later a mammoth $300 million deck replacement project got underway.
In 2009, the bridge logged its 150 millionth crossing, and the following year it was designated a National Historic Civil Engineering Landmark by the American Society of Civil Engineers.
In both 1958 and 2010, the United States Post Office issued stamps commemorating the Mackinac Bridge.
The steel monster has also made a number of appearances in films and television shows, including a ‘90s PBS documentary titled “Building the Mighty Mac,” the History Channel’s Modern Marvels, and Dirty Jobs with host Mike Rowe.
Though it’s only an option once a year, it’s possible to walk across the bridge every Labor Day, but only in the morning, because “Mighty Mac” is too important to be shut down for more than a few hours.