Buoyancy and Flotation:

Buoyancy and Flotation: The Sinking of the Edmund Fitzgerald

“The legend lives on from the Chippewa on down, of the big lake they call “Gitche Gumee.” The lake it is said never gives up her dead when the skies of November come early...”

Legends • Lake Superior, the largest of the great lakes is the subject of many folk tales and legends • November storms are notorious for their intensity on the lake, with furious cold winds • Read the following quote and describe how you would picture Lake Superior

"Those who have never seen Superior get an inadequate idea by hearing it spoken of as a lake. Superior is a sea. It breeds storms and rain and fog like a sea. It is cold, masterful, and dreaded."Rev. George Grant, 1872

“The ship was the pride of the American side coming back from some mill in WisconsinAs the big freighters go it was bigger than mostWith a crew and the Captain well seasoned.”

The EdmundFitzgerald • 75 Feet Wide • 711 Feet in Length • Largest Ship in Great Lakes when Built in 1958

Computer Simulation of Edmund Fitzgerald

Comparisons 15 Feet 360 Feet 729 Feet

STOP! • Before we continue.... • What are the pro’s and con’s of building such a large ship? • Complete the two column worksheet on “megaships” keeping in mind – this ship was considered “unskinkable”

“...With a load of iron ore twenty-six thousand tons more than the Edmund Fitzgerald weighed empty...”

One Large Load of Material • There was 860,950 cu ft. in cargo space on the “Fitz” • There were 26,116 long tons of taconite (iron ore) on board • There were also 50,013 gallons of diesel fuel on board.

Taconite • 1 cu. ft. of Taconite = 135 lbs and has 15,120 pellets per cu ft. • There are 112 Taconite pellets per pound • 1 cu. ft of Taconite will absorb 8-9 lbs of water per cubic foot • The space in between each pellet would hold an additional 27.5 lbs of water

Let’s Do Some MATH! • How many Taconite pellets were on the Edmund Fitzgerald when it sank? • There are 2240 lbs in a long ton • There are 112 pellets to the pound

Calculations • 26,116 tons = 58,499,840 pounds • 58,449,840 lbs * 112 pellets per pound 6.55 Billion!

“That good ship and crew was a bone to be chewed when the gales of November came early”

The Disaster • November 10, 1975 • Heavy Storm 50-75 mph winds • 15 – 20 foot waves of water • Entire Ship and 29 man crew lost at sea • The ship was 15 miles from safety

Course of “The Fitz”

“The wind in the wires made a tattletale sound And a wave broke over the railing And every man knew, as the Captain did, too, T'was the witch of November come stealing.”

Slt. St. Marie The path of the storm

Wind The result of the storm

“The dawn came late and the breakfast had to waitWhen the gales of November came slashingWhen afternoon came it was freezing rainIn the face of a hurricane West Wind”

The Storm • Came through mid-west, and turned north as it approached the Great Lakes • As the storm approached, the winds changed direction from NE to NW winds. • NW winds would blow across the widest part of the lake, increasing the size of the waves • See the weather maps from the storm

Storm Footage from the William Clay Ford – Several Hours Earlier

Weather • Severe Low pressure systems are common in Fall and Winter on great lakes • The combination of wind, waves, and cold water make these storms even worse in the colder months • See an animation of what happens in a low pressure system

Yoube the Navigator • Using your map, plot the location of the Edmund Fitzgerald as it moved across Lake Superior • Next, plot the position of the storm as it progressed across the Great Lakes. • Predict when the wind shifted direction

“The Captain wired in he had water coming in And the good ship and crew was in perilAnd later that night when his lights went out of sightCame the wreck of the Edmund Fitzgerald.”

The Sinking • Early in the afternoon, the Captain reported a bad list, lost radar, and the worst seas he had ever seen • At 7:10, “the Fitz” reported they were “holding their own” • The ship disappeared from radar not long after the last broadcast

Explanations • The sinking of the Edmund Fitzgerald has never been completely solved • The leading theory suggests the ship took on water through the hatch • The official report can be read here

Buoyancy • The force that causes things underwater to feel lighter • Pressure in fluid is higher on the bottom than on the top, resulting in a lifting force

Less Pressure Buoyancy More Pressure

Archimedes’ Principle • The buoyant force is equal to the weight of a fluid displaced by an object • As a result...If the buoyant force is greater than the weight of the object, it floats. • If the buoyant force is less than the weight of the object, it sinks.

So, What happened to “the Fitz” • Please secure the materials for the Buoyancy lab • You will need your “ship” • A container of “taconite” (it’s lead) • The water tray and dropper • Look at the explanations of the sinking as proposed by the Coast Guard and the Families of the Fitzgerald Crew • Make a hypothesis as instructed

When you are Finished • Compare your results of the lab to the possible explanations, and some of the evidence you have witnessed through this activity. • Is your hypothesis supported or rejected? • You and your partner should prepare to submit your findings and present your ideas to the class

Good Luck, and Good Science

Buoyancy and Flotation: