Industrial History: January 2020

(Bridge Hunter; Historic Bridges; HAER; Satellite, 2963+ photos)

This bridge is so famous that I didn't bother with a title that includes the body of water and adjacent town. It carries I-75 between the upper and lower peninsulas of Michigan.

"The Mackinac Bridge is currently the fifth longest suspension bridge in the world. The bridge opened to traffic on November 1, 1957." [MackinacBridge-Facts&Figures] It is still the longest in the western hemisphere. [MackinacBridge-MightyMac] The main span is 3,800'. The whole bridge is five miles long.

epa.gov via Bridge Hunter, I could not find it on epa.gov

The suspended span is a small part of the bridge.

Dave Bondy posted
Enjoying one last trip up north at the Mackinac Bridge before the colder weather hits

Jessie Jeo posted
Mackinac Bridge from 33,000'.
Matthew Cox posted
Mackinac Bridge from 33,000'. Feet up in the winter.

Michigan Memories posted
The Mackinac Bridge in 1977

Sandra Francis Young posted
Mighty Mac
[To summarize the comments, the bridge is 5 miles long but the main span is shorter than the Verrazzano-Narrows and Golden Gate.]
Laurie Johnson: When the winds are blowing 40 + miles an hour you can definitely feel the swaying of the roadway. Sort of like a carnival ride LOL.

Ochoa Warines posted, cropped

Mackinac Bridge

The Mackinac Bridge is a suspension bridge that connects the Upper and Lower peninsulas of Michigan. It spans the Straits of Mackinac, a body of water connecting Lake Michigan and Lake Huron. Construction began on May 7, 1954 and the bridge opened to traffic on November 1, 1957.

Lloyd Scott Hardin shared

Iris Burris posted
International Space Station crew shares overhead view of Mackinac Bridge

David Warner posted
Mackinac Bridge from 33,000'.

Mark Blouin posted
Picture from plane

Bob Conrad posted
Under the bridge

Alex Raz posted
One of the most unique photos I've ever seen of the Mighty Mac.Cool photo very unique of the Mighty Mac
[The comments have some more photos from underneath.]

Melody Woods posted two photos with the comment: "Not your traditional view but absolutely gorgeous!"

John Hilary commented on the above post
Great shot! I took this February 14, 2021 when we were there to see the blue ice.
Melody Woods: John Hillary thanks! I have always wanted to see the blue ice.
Arnold Romppai: John Hillary no ice anywhere this year [2024]

Interlake Steamship Company posted
Super cool photo from our M/V Mesabi Miner tonight! Taken by our Chief Steward Sissy Payment as she grilled peppered bacon wrapped filet mignon and asparagus while going under the Mighty Mac.

Frank P. De Simon posted
The Mac beyond the Mackinaw Straits Lighthouse. Summer 2015

Mackinaw Area Vistors Bureau posted
Wow! Just Look at those reflections in the water! 🌊🤩
When’s the last time you’ve seen #MightyMac at night? 🌙
We love this incredible capture from @captures.by.ethan 📸
[The comments contain a couple more night-time photos.]

Great Lakes Weather & Climate posted

👀 Impressive cloud deck rolling into the Mackinac Bridge this morning (11/24/23) as viewed from St. Ignace.

📸 Pic courtesy of Karl Grundemann

[Sometimes the Facebook suggestions are appropriate.]

Wright Jessica posted
The Northern Lights over the Mackinac Bridge [Michigan]

MightyMac.org posted
Construction of the Mighty Mac in the spring of 1957. MBA photo courtesy of Superiorland Library Cooperative.
John Coulombe: Is that the north or the south part?🤔⚓
MightyMac.org - The Mackinac Bridge & Straits of Mackinac: John Coulombe North.
Michigan Film Photographer Karl Wertanen shared

MightyMac.org posted
This double suspension Bridge across the Straits of Mackinac was being considered in 1940 and the causeway at the north end of the bridge was built. WW2 stopped that project, but the causeway was incorporated when the Mighty Mac was built in the 1950s: http://www.mightymac.org/bridge.htm

MightyMac.org - The Mackinac Bridge & Straits of Mackinac posted
The Mighty Mac on a sunny day last week [Early May 2021]. Photo by AM.
James Torgeson shared
Another fine product of the American Bridge Division of United States Steel!

MDOT's Facts&Figures has some construction photos, although they are frustratingly small. What caught my eye is that no one knows the depth to bedrock at the midspan! At the piers, they had to go through up to 142' of water and 105' of overburden. The truss is rather deep. The height of the roadway is 199' whereas the clearance for ships is 155' Once again, Laker dimensions are bigger than Seaway dimensions because the Seaway requires only 116.5'. [CanalDimensions]

Best Western Hotels & Resorts posted

MackinacBridge-History

Only In Michigan posted
A captivating capture of the bridge to Paradise. Photo Credit: Daniel Baldwin/Michigan Nature Lovers Group on Facebook

Diane Russell posted
Unused postcard showing Mackinac Bridge in winter.
[Some comments indicate it is looking North.]
Marijane Woodbury: Crossed the bridge many times in the winter! One year we followed a snowplow across in a Blizzard,never been so scared in my life, never saw the bridge, the longest five miles in my life.

Art, Craft & Architecture posted
The Mackinac Bridge, Michigan USA was the longest suspension bridge in the world when it opened on November 1, 1957, at 8 km in length, it rises 168 m above the water surface at its highest point.
📷 ✨ source: @buffyandhenrietta on http://bitly.ws/HJuG

MWRD posted
This photo of the north tower of the Mighty Mac was taken during a helicopter flight with MyFlight Tours.

Before the bridge was built, the line waiting for a ferry could get real long, especially during deer hunting season. One year it was reported to be 27 miles long the night before deer hunting season opened.

MackinacBridge-History

The history page on the MDOT and authority web pages have the same text. I recommend the MDOT web page for the history of the bridge because it has better formatting.

A State Of Copper posted
Mackinac Bridge Main Towers are 552 ' above water and 210' below. Unbelievable engineering.

A State Of Copper posted
Good Morning Michigan!! One of my favorite snaps of crossing the Mackinac Bridge.

MightyMac.org - The Mackinac Bridge & Straits of Mackinac posted
This beautiful shot of the Mighty Mac was taken yesterday by Todd Anderson.

Window On The Water Photography by Chris Murray posted
“There is only one way to understand a lonely bench in a park: Sit on it; watch whatever it is watching; listen whatever it is listening to! Sit in spring, sit in winter, sit in summer! To understand something deeply, you need to live its life!”
― Mehmet Murat ildan

Interlake Steamship Company posted

Perfectly timed shot of our 1,004-foot M/V James R. Barker sailing under the Mackinac Bridge yesterday!

DYK: The Mackinac Bridge is the state of Michigan's single largest asset. As one of the world's leading suspension bridges, the five-mile Mighty Mac provides passage over the Straits of Mackinac and connects the Upper and Lower Peninsulas of the state.

: Randy Wolf

David Nagorsen: Here is another little-known fact about the Straits of Mackinac. The federal government wanted one state to control the Straits of Mackinac. Michigan was granted the upper peninsula as part of its state. The trade-off was Michigan had to give up Toledo, which was going to be a part of Michigan.

Fred Ryerse posted three photos with the comment:

What were the odds? Maybe better than I know, but I still think this doesn't happen very often. The largest freighters on the Great Lakes are 1,000 foot freighters. These are the largest ships possible to pass through the Soo Locks in Sault Ste. Marie, Michigan. There are only 13 of them throughout the Great Lakes. Early last evening, there were two of them which were passing under the Mackinac Bridge at the same time. The Presque Isle and the American Spirit.
I saw it start to play out as we were sitting on the deck, so I quick grabbed the camera and here are three shots in sequence.

Fred Ryerse shared

I never appreciated how long the deck truss segment of the bridge was until I saw this photo. And we still don't see the truss reaching the shore.

LEM Photography - Michigan posted
Who is ready to cross this beauty and spend their summer vacation in the U.P? I sure am! A beautiful sunset at the Mackinac Bridge, summer of 2020.

Here is another view that shows the suspended span is a rather small part of the whole bridge.

Craig Hensley Photography posted

Moody Mac 

After raining for the majority of the day the skies let up for a few minutes and I popped the drone up for a look. 

Tech:DJI Mavic Air 2s
Date: 9/4/21
Location: St Ignace, Michigan

Keyhole Bar & Grill posted seven photos with the comment: "Ironworkers can tend to be a little high maintenance sometimes. Before the first section of tower was set on July 5th, 1955, they were assembled on the ground in Ambridge Pennsylvania to make sure they fit together properly. They were then dismantled and shipped to St. Ignace by rail, loaded up on a barge and taken to where they have stood for the last 66 plus years. Each section weighed 19 1/2 ton. They assembled 50 feet a week until they reached 552 feet above the water. The last photo is the first section of tower being set on July 5th, 1955. Each tower weighs approximately 3250 tons. Quite the feat. Enjoy the Day!"

James Torgeson shared

Some scenes of the American Bridge Division of USS building Mighty Mac! Note the photo of one of the towers being assembled on the ground at the giant American Bridge home plant in Ambridge. (By the way, the Keyhole Bar in Mac City has great food!)

Bridges Now and Then posted
"Mackinac Bridge, Pier 18, December 1, 1954. When the rectangular caisson for the south cable bent pier was finally anchored on rock at the bottom of the Straits, the rectangular form was cut off at 8 feet below the surface. The two circular concrete towers surrounded by wrought-iron were constructed from 8 feet below the surface to 10 feet above it. In the spring of 1955, steel towers were erected for a height of about 90 feet above the concrete foundations." (Mackinac Bridge Authority)

Dale Jones posted
Circa 1957! Beautiful beginnings!!!!

Antonio Medina posted seven photos with the comment: "Random Thursday post. Straits of Mackinac Bridge and Deck Trusses. Mackinaw/St. Ignace, Michigan, November 1957. Source- Mackinac Bridge Authority."

Epyon Royal posted
Mackinac Bridge during construction.

Michigan Memories posted
Mackinac Bridge in the 1950s

Douglas Vernon: Photo by Ken Teysen of Mackinaw City

Marcia Fry: You can go on the Mackinac Bridge Authority's Web site and see my dad's photos. Herman Ellis.

Janice Campbell: This was about 1956 or later. Married in 1955 and only the cement anchors were in nothing else

Roger Priebe posted four photos with the comment: "1957 - the final mid-span section of the stiffening truss is towed out to the Mackinac Bridge and lifted into position [ Upper Peninsula Digital Network photo ]"

Roger commented on his first photo
how it started

Eddie Gough posted
Many people joking about the GH bridge not aligning, here is a pic of the Macs" center span and the final connections being made, no computers back then, all slide rules. It took 3 seasons to triangulate all 33 piers to within 1/10 inch of center, that is one straight line. The final panel section did align on target but it took the men hrs to pin it due to expansion and contraction of the steel. Michigan's finest engineering achievement.
[But this is a suspensions bridge, not a cable-stayed bridge that has two independant haves until they are joined.]

William Oldani: It's Interesting to Note that Michigan's finest Engineering Achievement was made by David Steinman from New York!

Dan James: William Oldani Not just Steinman. 1 of the firms top engineers, P.eng Abul Hasnat, is not given enough credit.

Bridges Now and Then posted
"Construction of the 7,400 ft long [2.25km and 1.4 miles], three-span Mackinac suspension bridge, which connects Michigan’s Upper and Lower peninsulas, began in 1954." (Photograph courtesy of MDOT)
[The comments have some photos of the completed bridge.]
History's Mirror posted
[The description sounds like AI generated platitudes.]

And near the finish.

Ironworkers building the World posted
Charles Wellman: I did not know they barged assembles out and hoisted into position. I assumed they were stick built in place.

Keyhole Bar & Grill posted
You too could build a bridge and use wrought iron plates to protect the cement just like the Mackinac Bridge. Just write for your copy. Vintage ad from 1955. Enjoy the Day!
James Torgeson shared
An A.M. Byers ad showcasing their contribution to Mighty Mac.

Chris Kooyers commented on the Keyhole Bar & Grill post

Ana Roy posted
Not sure what it is that fascinates me about construction photos of the Mackinac Bridge. I have always been in awe of the engineering of the job ... and knowing that from design beginning in January 1953 to opening of the bridge to traffic on November 1, 1957. And as if that time frame of only 4 years wasn't impressive enough, all of the highly complex calculations were done with mathematicians and engineers using slide rules and pads of paper - no computers to do the structural analysis. Even the calculation of when and how tight to cinch down each bolt and adjust the final tension of each cable was done that way. About 40 years later I attempted to use a finite element analysis program to make some of the same calculations, and found it daunting - but also found that the computers could barely have calculated any more precisely - from the dimensions of the beams to the building of the cables, strand by strand. This bridge is not just a monument to those who built it, but also those who figured out HOW to build it. If we take good enough care of it, there is good reason to think it will still be there for my great-great-grandchildren to cross safely, just as my grandparents did back in 1958.

Lincat Photography posted
A unique shot of below the Mackinac bridge shipping channel level.
Mike Mishler shared

Neal Childs posted
Under the Mighty Mac

Kathy Firestone posted
In 1947 the 65-foot Bide-A-Wee was converted from a steam powered vessel to an oil screw. In 1956 US Steel Corporation purchased the Bide-A-Wee from Milo B Welch. The steel-hulled boat was remodeled to become a work boat, classified as a tender, and was one of many used by the Mackinac Bridge Authority to transport men and materials around the work site during construction of the Mackinac Bridge. The name was changed to Bridgebuilder X. The gross tonnage decreased from 45 to 37, with remodeling done by U. S. Steel. The X in the name stands for the number 10, so there were, apparently, at least nine other boats used during the bridge construction.

Mike Harlan shared
Bob Haworth This Bridgebuilder X was lost on Lake Michigan. I don't think it's been found, and no one survived.
[This photo motivated writing these notes. It appears the cable is done and they have started hanging the deck.]

One of 16 photos posted by David Brown from the mid 1970s

It is hard to capture that the suspended span is a small part of the 5-mile long bridge.

MackinacIsland.Net - Mackinac Island Michigan posted
We’re getting an early start on the Memorial Day Weekend. It’s a beautiful Wednesday morning on the Straits of Mackinac. Here’s a view of the Mackinac Bridge shining in the morning sun.

Amy Digon posted
Queen Elizabeth's royal yacht Britannia passing under the Mackinac Bridge on July 5, 1959. Traffic was halted at each tower for security, but hundreds of people left their cars and ran out on to the center span shouting, waving and seeking a view of the Queen. This was mid-day on Sunday of the Independence Day weekend and resulted in what was called one of the worst traffic jams ever in the Straits area. Photo courtesy of the Mackinac Bridge Authority.
[mlive, The 33-year-old queen came to North America for the opening ceremonies of the St. Lawrence Seaway and spent six weeks touring various cities. The five-year-old, 412' yacht visited one city in the US --- Chicago. The bridge had been opened less than two years.]

Danny Thompson shared
William Gray I have home movies of the Britannia passing our house on Harsen's Island. The parade of ships, naval and otherwise was astounding!

Courtesy Mackinac Bridge Authority/MDOT via mlive
[The mlive article has the following video and several more construction photos.]

Bruce Edwards posted
Found this photo in my FB memories this morning. Comments from contributor Aaron Thompson, the man shown is engineer John Cortopassi and the photo was taken in March of 1957.

Please click this link for many more photos of the construction. Note that you have to click an arrow at the bottom of the photo collection to go to another page of photos.

Mick Breznai posted, cropped
The building of the Mackinac bridge, Northern Michigan, unsure of who produced the plate and structural steel, or who built it.
Charles Miller: The plates and steel were made at USS GARY WORKS . SECTIONS WERE FABRICATED AND ASSEMBLED AT THE USS AMERICAN BRIDGES IN GARY TO BE SURE EVERY THING FIT CORRECTLY THAN DISSAMBLED AND SENT to the location and assembled. My best friend worked on the walk way sections at the American bridge in gary indiana
James Torgeson: Charles Miller The towers were actually loosely assembled flat on the ground at the American Bridge home plant in Ambridge, PA, which was also the the largest fabricating plant in the World.
Phil Vaclavik: Most of it floated up Lake Michigan on barges.: Michael Shirey most of it floated up Lake Michigan on barges.
Mike Ridenour

Phil Vaclavik incorrect. The only long range floating was of the caissons and those were floated up Lake Huron from Alpena, Michigan where they were assembled.

Everything from Gary Works was brought by rail to Alpena, Mackinaw City and St. Ignace.

Here’s a great documentary on the construction of the bridge.

https://m.youtube.com/watch?v=C07hGxEij3M

Jan Ballard

Here's a link with more pictures.

http://mightymac.org/buildingmackinacbridge.htm

Phil Vaclavik

https://youtu.be/CCOcpzgT5FU

Jan Ballard commented on Nick's post
John Zurawski: Jan Ballard Jan of GLS?
Jan Ballard: John Zurawski yep...

Alon Delores posted
c.1956 - Mackinac Bridge construction before the freeway
[ Bridge Authority photo ]...

Bridges Now and Then posted
Lifting a section of the Mackinac Bridge into place, 1956. (All Things Michigan)

James Torgeson posted
More American Bridge goodness, this time building Mighty Mac! This view looks north towards St. Ignace, MI.

Robert Campbell posted
The Alva C. Dinkey going under the unfinished Mackinac Bridge. Photo courtesy of the Michigan Department of Transportation.

Walter Jung posted
Construction of the Mackinac Bridge - unused, copyright 1957.

Gary Skory commented on Walter's post
The view from the top of this iconic Michigan landmark is awesome++...October, 2010, north tower...with the Arthur M Anderson passing westward.

(new window) silent film Courtesy Mackinac Bridge Authority/MDOT via mlive

This mlive page is supposed to have a gallery of 30 construction photos, but I could get just ten photos to display.

Tom Harvey posted
Mackinac Bridge Construction - dated 1955.
James Osborn "Hatch farm". The old boats had twice as many hatches....24 foot centers, but it was a hatch every 24 feet! Later, it was a hatch every 48 feet. That boat is an old "hatch farm".
Gary Schweitzer James Osborn 12’ centers. Changed to 24’ later.
Anne H. baker posted
Construction of the Mackinac Bridge in 1955
Janey Anderson shared
How cool is this shot!!

AaRon Thompson commented on Janey's share
I took this one in 2017
[A comment indicates this is Gott.]

AaRon Thompson commented on Janey's share
This one here is the Laud.

Robert Campbell posted
This photo from the Michigan Department of Transportation Department collection shows the Thomas Lynch sailing under the unfinished Mackinac Bridge.

Jamie Reed posted
James Torgeson shared
An ironworker from the American Bridge Division of US Steel acknowledges the photographer while working on the suspension cables of the Mackinac Bridge.

safe_image for The Mackinac Bridge
Looking north through the cable saddle at top of south tower of the MackinacBridge. May 23rd, 1956...….65 years ago!!!

The American Bridge Division of US Steel has completed the towers for the Mackinac Bridge and the main cables, suspenders and deck are still to be done. This 1956 view looks through one of the huge cable saddles on the south tower towards its northern counterpart.

The longest suspension bridge might be a topic like the largest steam locomotive --- it depends on what you measure (between towers or cable piers or anchors). MDOT's About calls this the third longest suspension bridge whereas MackinacBridge-Facts&Figures calls it the fifth longest. Or is the MDOT web site out of date? HistoricBridges also calls it the third longest. It was the longest in the world when it was built, and held that record for several decades.

The 1940 collapse of the Tacoma Narrows Bridge was still fresh on everyone's mind when this bridge was designed in the mid 1950s. The stiff truss is designed to eliminate micro movements such as longitudinal waves caused by wind induced resonance and torsional (twisting) waves caused by aeroelastic flutter forces. It is not designed to eliminate macro movements. "It is possible that the deck at center span could move as much as 35 feet (east or west) due to high winds. This would only happen under severe wind conditions. The deck would not swing or 'sway' but rather move slowly in one direction based on the force and direction of the wind. After the wind subsides, the weight of the vehicles crossing would slowly move it back into center position." [MackinacBridge-MightyMac]

"Over the five mile length of the bridge, 27 feet of expansion ability had to be provided....Changes in temperature also cause the length of the main cable to change. In warm weather, this causes the cable to lengthen and thus at the center of the bridge the cable lowers. A distance of up to seven feet (with six feet the typical expected maximum) of cable movement up and down was provided for. The movement of the cable would be even greater if it weren't for the fact that when it warms up, the towers holding the cable become taller, counteracting to a small extent the lowering of the cables." [Historic Bridges]

Lizbeth

Onekama, MI posted

With Mother Nature giving us another taste of winter on Christmas Eve and Christmas Day, thought showing  some of the most popular western and northwestern Michigan photos (on this page) from winters past would be appropriate 

Best viewed in front of a warm fire.  A big thank you to the photographers that braved the ice and snow to get these photos

Winter drive at the mighty Mac - Photo from the UP Cruisers

Two of the ten photos posted by Don VeVier.

One of four photos posted by Don BeVier
Presque Isle in the Straits of Mackinac , 9-11-20

Al Miller posted
Today is my birthday, so I'm indulging myself by posting my first boat photo in 1970 -- a U.S. Steel AAA-class boat downbound on Lake Michigan after passing under the Mackinac Bridge. I shot it with my new Kodak Instamatic -- the high-tech model that used flashcubes. Sad thing is, this isn't the worst boat photo I ever shot. The nice thing is, seeing this boat inspired my interest in the Great Lakes.

Chris D Holton posted three photos with the comment: "A few photos from the building of the Mackinac Bridge 54’-58’
All floating rigs belong to Merritt Chapman Scott."

1
Perry Brumm Northwest Model 6 w/mast!

Robert MacKenna commented on Chris' post
About 30 years ago I was given a copy of the pictorial history of the bridges construction... should have remembered those pictures as they are all in this book. I would urge any interested to try to get a copy. It was put out by the Wayne State University Press in 1958

Josh Davis commented on Chris' post
One of my favorite places to go. You sit and look at how that bridge was built and think about the iron they had to do it with.
I really hope that Enbridge tunnel goes. I would like to be a part of that job.
[The Enbridge tunnel would replace two 1953 20" pipelines on the bottom of the Straits of Mackinac with a pipeline in a tunnel. Engridge has a poor record concerning oil spills. [OilAndWaterDontMix] Enbridge makes it sound like the product in this "Line 5" pipeline is going to Michigan instead of Eastern Canada. [enbridge] The tunnel would cost $500m. [DetroitNews]
Update: trouble with the pipelines (source)]

Eddie Gaugh posted
South Tower, A 7 ton baseplate is lowered to the tower pedestal. Tower foundations now complete, now begins the 6500 tons of steel to go skyward 552 feet.

Nick Breznai shared

Aaron Thompson commented on Eddie's post
July 5, 1955 press photo of a milestone in the construction of the Mackinac Bridge. The first section of tower being set on it's foundation. Section weighs 39 1/2 tons. They were erected at the rate of 50 feet per week until they hit the 552 feet mark.

Eddie Gough commented on his post

Highway Engineering Discoveries posted
Tightening bolts on span 4-5, Mackinac Bridge, June 2, 1956. (Michigan Department of Transportation)

Al Miller posted
Edgar B. Speer downbound for Lake Michigan as it approaches the Mackinac Bridge on Sept. 7, 2007.

MightyMac.org posted
The crews of Coast Guard Cutter Mackinaw, homeported in Cheboygan, Michigan, and Canadian Coast Guard Ship Pierre Radisson, homeported in Quebec City, conduct an escort on Lake Superior near Whitefish Point April 3, 2014. As crews worked together, as part of an ongoing bi-national agreement between the U.S. and Canada, to break sheet ice that was nearly 40 inches thick. (U.S. Coast Guard photo courtesy of Coast Guard Air Station Traverse City)
Don Slusser shared

Construction Photos via a Facebook share

Beau Soleil Langlois posted
St. Ignace teenagers Sandy Gustafson and Janice Steiner assist Mackinac Bridge worker Mel LaChapelle with changing a lightbulb on the main cable in spring 1969 in this promotional photograph for the bridge. There are 96 lights on the bridge’s two cable lines. (Republican News Photo by Mackinac Bridge Authority photograph by Herman D. Ellis) (Thanks to Mike Cronan for sending this along)

Craig Hensley Photography posted

Mighty Mac! 

The Mackinac Bridge opened in 1957, the 26,372-foot-long (4.995 miles) is the world's 24th-longest main span and the longest suspension bridge between anchorages in the Western Hemisphere.The bridge connects the city of St. Ignace on the north end with the village of Mackinaw City on the south.

Tech: DJI Mavic Air 2s

Kenn Forbes: That's a great shot! Though I feel your phrasing is a little misleading. The main span is 3,800ft. The suspended length is 8,344ft. The the total length is the 26,372ft as mentioned. Regardless, a beautiful and spectacular piece of engineering!!

MightyMac.org - The Mackinac Bridge & Straits of Mackinac posted

42,000 Miles of wire went into the construction of the cables for the Mackinac Bridge. This tool was used to add a new spool of wire when the previous one ran out.

4 pages of photos from the construction of the Mighty Mac: http://www.mightymac.org/buildingmackinacbridge.htm

(new window) Aerodynamically designed for winds up to 600 mph