Today is the 35th anniversary of the sinking of the Great Lakes ore carrier, the Edmund Fitzgerald. The shipped was sunk by “The Witch of November”, a strong Lake Superior storm that often occurs around the same time each year. Given the anniversary and recent storm that set several all-time low pressure records, I thought I’d collect summaries of some of the most significant storms.
A frequent warning from people who see a quickly warming world is that the extra heat means extra water vapor, which provides energy for stronger storms. This post won’t really challenge that, I’d need a more complete records and various statistical methods. Look at this post more as weather lore than climate analysis. The recent storm may fit the “stronger storm” hypothesis, but some of the storms from decades ago were not taken lightly!
Many of these storms combine three elements. First, a Pacific storm moves into the northwest and continues just south of the Canadian border. Between mid-autumn and mid-winter, small systems can feed warm moist air from the Gulf of Mexico north and cold Canadian air south. When the Pacific storm moves into this environment, it can wrap both air masses together and “bomb out” into a major storm. Little glitches in the timing can have a big effect on the final strength, which is a good reason to be suspicious about looking for a global warming signal in the historical record. Too many things have to line up just right for a big storm
I thought I could compile this list with just storms between the Fitzgerald storm and the recent one, but it quickly became clear that some older storms were worse and caused greater damage. Of course, weather prediction was not as good as it is now, and some of these storm triggered significant improvements in getting out weather warnings. The human and shipping impacts I note below are poor items for historical comparison. Also, some of my data sources are unclear or categorize ship impacts differently.
The links below have the real meat about the storms. I’ve included a quote from the last link for each storm. Some of them would be difficult events to handle today.
1913 November: “Freshwater Fury” 968.5 mb = 28.59″, 19 ships sunk, 250 deaths
http://www.pointeauxbarqueslighthouse.org/preserve/shipwrecks/1913storm.cfm
http://www.crh.noaa.gov/dtx/stm_1913.php
“No lake master can recall in all his experience a storm of such unprecedented violence with such rapid changes in the direction of the wind and its gusts of such fearful speed! Storms ordinarily of that velocity do not last over four or five hours, but this storm raged for sixteen hours continuously at an average velocity of sixty miles per hour, with frequent spurts of seventy and over.
Obviously, with a wind of such long duration, the seas that were made were such that the lakes are not ordinarily acquainted with. The testimony of masters is that the waves were at least 35 feet high and followed each other in quick succession, three waves ordinarily coming one right after the other.
1940 November 11: “Armistice Day” 967 mb = 28.55″, 5 ships, 150 deaths
The summer and early autumn in 1940 were warm, as was the morning of the 11th. Many people were out duck hunting in the mild weather and were unprepared for the changes about to move in. By the end of the day wind made it dangerous for the hunters to move by canoe, some made it out the next day over thin ice, others died before then. Up to 27″ of snow fell in Minnesota.
The storm brought 49 deaths in Minnesota. It sank 5 ships and killed 66 on Lake Michigan. The west coast storm associated with this caused the collapse of “Galloping Gertie,” the bridge over the Tacoma Narrows that had been completed earlier in the year.
http://minnesota.publicradio.org/display/web/200011/10_steilm_blizzard-m/
http://www.carferries.com/armistice/
http://www.wsdot.wa.gov/tnbhistory/Connections/connections3.htm
1975 January 11 “Great Storm of 1975″ Canada: 961 mb = 28.38″, Duluth MN: 967 mb = 28.55” 45 deaths in the Midwest
Associated with this storm was a major tornado outbreak in southern states (yes, in January). In Sioux Falls, South Dakota it was called the biggest blizzard of the century. In Brainerd MN it was was compared to the Armistice Day storm and the ambulance service used a snowmobile with an enclosed trailer.
http://en.wikipedia.org/wiki/Great_Storm_of_1975
http://www.brainerddispatch.com/history/pages/1024/1024_Blizzard_01111975.jpg
1975 Nov 10 “Edmund Fitzgerald” 976 mb = 28.83″ 29 deaths
This, of course, is the storm that sank the Edmund Fitzgerald, a great lakes ore freighter. These ships are narrow to fit the locks between the lakes and very long, the Fitzgerald was 729 ft (222 m) and the largest on the lakes for most of its life. Exactly why the Fitzgerald went down is not certain, but waves fore and aft may have let the middle buckle, as the ship is in two pieces on the lake floor. Whatever happened was so quick that there was no distress call. Their last communication with another ship nearby said they were holding their own.
http://cimss.ssec.wisc.edu/wxwise/fitz.html
http://www.glerl.noaa.gov/pubs/fulltext/2006/20060016.pdf
http://www.gordonlightfoot.com/wreckoftheedmundfitzgerald.shtml
The wind in the wires made a tattle-tale sound
and a wave broke over the railing.
And ev’ry man knew, as the captain did too
’twas the witch of November come stealin’.
The dawn came late and the breakfast had to wait
when the Gales of November came slashin’.
When afternoon came it was freezin’ rain
in the face of a hurricane west wind.
1978 Jan 26 “Great Blizzard of ’78” Cleveland: 958 mb = 28.28″, Canada: 950 mb = 28.05″
By some accounts, the entire winter of 77-78 was the worse since records began in the early 1800s, but this storm was by far the most severe of the 18 major storms. This affected an area further east than most of the storms mentioned here. Cleveland set its all time low air pressure, and most reports come from Michigan, Illinois, and Ohio.
This storm brought rain to the east coast which melted some of the record breaking snowfall from a storm a couple weeks earlier, and before New England’s “Blizzard of ’78.” When people talk of the storms of the late 1970s, this is one of the winters they’re talking about.
http://www.sws.uiuc.edu/pubdoc/RI/ISWSRI-88.pdf
http://www.crh.noaa.gov/dtx/stories/blizzard1978.php
While there are several contenders for the worst blizzard ever to hit the Great Lakes in relatively modern times (since 1870 when records began in Detroit), the immense and intense Blizzard of January 26-27th 1978 must rank at or near the top along with the Great White Hurricane of 1913 with its similar track and powerfulness.
1998 Nov 10-12 “Anniversary Storm” 963 mb = 28.43″
Duluth set records for lowest air pressure, precipitation, and snowfall.
Finding web pages about this is a bit of a challenge. Several mention it in passing while their main thrust is on the 1975 Edmund Fitzgerald storm 13 years before. January is 1998 featured the Great Ice Storm of ’98 which kept me busy through the spring chipping downed wood. In Canada that storm took out a line of high tension towers and disrupted power distribution for months.
The wisc.edu link has a nice animation of satellite photos of the this storm – and links to a track page that notes “uncanny similarity” to the 1975 storm.
http://climate.umn.edu/doc/journal/981110.htm
http://itg1.meteor.wisc.edu/wxwise/AckermanKnox/chap10/nov98.html
No quote, but the latter URL has a nice satellite image animation of the 1998 storm.
2010 Oct 26 “Chiclone” 954.9 mb = 28.20″
Strongest non-tropical storm on record in the non-coastal continental United States (whew!)
http://blogs.fox11online.com/2010/10/
http://climate.umn.edu/doc/journal/low_pressure_101026.htm
[This is a quote from a Duluth MN NWS statement originally issued in all capital letters.] An unusually intense low affected the state of Minnesota. At 513 PM CDT…the automated weather observing system at Bigfork Minnesota recorded a 954.96 millibar /28.20 inches/ pressure. This breaks the all time Minnesota state record for the lowest observed pressure.
The previous record was 962.6 mb set on November 10 1998 at Albert Lea and Austin in southern Minnesota. The record was initially broken shortly after 10 AM as the low passed by Aitkin Minnesota. However…the low continued to intensify into the afternoon.
A final note.
Trying to pull out a consistent history from widely disparate records for this has been a time consuming exercise. Accounts of one storm differ with the teller. One story might refer to the lowest pressure in the state, another mig refer to the lowest pressure in the US or Canada, some might even refer to the pressure described on a synoptic map but not recorded on a barometer.
Jeff Masters reported this list of the six lowest pressures recorded in the Great Lakes area:
1. Yesterday’s October 26, 2010 Superstorm (955 mb/28.20″)
2. Great Ohio Blizzard January 26, 1978 (958 mb/28.28″)
3. Armistice Day Storm November 11, 1940 (967 mb/28.55″)
4. November 10, 1998 storm (967 mb/28.55″)
5. White Hurricane of November 7 – 9, 1913 (968 mb/28.60″)
6. Edmund Fitzgerald Storm of November 10, 1975 (980 mb/28.95″)
However, he referred to a post from the Chicago NWS office from during the storm. Its list is:
Rank Event Date Minimum central pressure
1. Great Ohio Blizzard Jan 26, 1978 950 HPA / 28.05 inches
2. Current event Oct 26-27, 2010 962 HPA / 28.41 inches *
3. Armistice Day Storm Nov 11, 1940 967 HPA / 28.55 inches
Anniversary Storm Nov 10, 1998 967 HPA / 28.55 inches
4. Cyclone of 1913 Nov 7-9, 1913 968 HPA / 28.60 inches
(aka White Hurricane)
5. Edmund Fitzgerald Storm Nov 10, 1975 980 HPA / 28.95 inches
* current lowest minimum central pressure
Note how Masters uses an updated pressure reference for this year’s storm, which is fine, but he replaced the Canadian pressure in the 1978 storm with the Cleveland pressure thereby knocking 1978 into second place.
Perhaps the moral of the story is that Americans can wring their hands over storms getting worse, and Canadians can maintain their focus on melting permafrost and hungry Polar Bears.
I’ll just settle for using this as confirmation that it’s tough finding the “right” numbers.
The Great Blizzard of 78 dumped so much snow between Port Colborne and Welland (Southern Ontario – near Buffalo) that people had to actually dig tunnels to get out of their houses as snow was piled up to the roofs. Snowmobiles were the only way to get around for days. I believe the military had to help in bringing food to people snowed into their homes. There was an actual case of a car parked on top of a school bus on the major roadway as people left their vehicles because of the vicious blizzard conditions (could not see in front of the car). I don’t know what the official snow depth was for the area but because of the wind snow drifts were up to the tops of telephone poles.
We have to keep this sort of memory going. Not wishing to wax lyrical about conspiracy theories, but I am convinced that the UK Met Office, in its weather reports, are forecasting all sorts of “extreme” events – all due to climate disruption, natch – and then conveniently not reporting on the actuality the next day. The number of times recently I have gone out in the morning armed with waterproofs, hat, unbrella etc anticipating the forecasted downpour and then not needed anything at all, the sun has shone instead.
But every time there is a flood/heavy rain/snow/whatever and it is then reported as evidence of climate disruption, we must be able to negate that with evidence from previous years, as far back as possible. I went to a climate change seminar recently (to keep an eye on what sort of rubbish is spouted by the believers) and a speaker produced a slide showing a series of pictures of a warehouse by the side of a river in Sheffield (the seminar was in the south west!) which had NEVER flooded before apparently (and that made me want to ask why – was it clogged up with abandoned supermarket trollies?) and the stupid warehouse owner had made no emergency provision for an extreme flooding event. Each slide the water progressing rapidly across the car park outside the warehouse until it entered the warehouse so that, silly, silly person, his business was completely disrupted for weeks, nay months, afterwards. And it was all because of climate disruption.
I stayed for the morning and had to leave by lunchtime. I couldn’t stomach any more. But there were many people there with similar views as myself which was reassuring.
nofate says:
November 10, 2010 at 8:46 am
> That picture of the Edmund Fitzgerald really brings back a lot of memories,
Oh good. I struggled a bit with what image to use on the post. Other candidates were synoptic maps of that storm or a similar one, the presumed track of the Fitzgerald trying to stay out of the long wind fetch (until it changed to astern), or this halcyon day.
This won out as the Great Lakes freighters are so unusual. Oceanic container ships are always shown with low density containers piled high. Not at all like iron ore freighters! Besides, the central theme is the Fitzgerald’s demise.
Nature is awesome and greater than the science that tries to capture it.
There were reports of surfing 20-footers in Michigan this October. This AGW thing could be good for the MI surfing industry. Not that I’m going to “get in on the ground floor” of this movement with my own money.
Along with earlier springs and later winters, the November Witch now comes in October. That pretty much cinches it, scientifically speaking. Not.
Roy Spencer says:
November 10, 2010 at 9:49 am
As in most endeavors, various weather services and others have learned much from mistakes or events that expose problems. These storms seem to have inspired more more changes than most. A quote from the 1940 storm I didn’t use above is from http://minnesota.publicradio.org/display/web/200011/10_steilm_blizzard-m/ :
But perhaps the most embarrassing revelation was that no one was watching the storm’s explosive development in the pre-dawn hours of November 11. A retired government forecaster says the Midwest headquarters in Chicago was not staffed overnight. The uproar led to several changes. The Chicago office went to round-the-clock operation and the Twin Cities branch was upgraded so it could issue forecasts.
Meteorologist Paul Douglas says the Armistice storm still resonates today.
“Meteorologists shudder when the Armistice Day blizzard subject comes up. I think technology has helped and we would not be caught again with some of the new technology. But certainly there can still be scenarios where we are surprised, where we are caught and that’s why this can be such a humbling profession.”
In New England, the Blizzard of 1978 (in February, not the midwest’s blizzard in January!) marks the point of taking the models seriously. The LFM (I think…) did a good job forecasting the storm several days in advance and gave much better warning than did humans with decades of experience with New England weather. Besides, the humans are more reluctant than are computer programs to forecast record setting events. This is not to say the models have New England completely figured out yet!
OT? Interesting article:
SUN-EARTH-VENUS ALIGNMENT
http://daltonsminima.altervista.org/?p=12129#comment-34130
As a North Shore resident of Lake Superior, that was definitely a wind maker back in Oct. Odd direction for such strong winds though. With the storm centered to the W, then NW of me, we had very strong SW winds which really buffeted the shore at an odd angle. Normally we get very strong winds from the E or the NW from such systems. They did start out from the E, but weren’t as strong until they went SW. Trees down all over with roofs being stripped of shingles along the shoreline. 2 to 3 inches of rain with up to 7 in of snow in the hills. A very dry Oct turned very wet in just a short couple days. We had local flooding issues as well.
My own forecasting showing some pretty wild weather between Thanksgiving, and Christmas this year. Lots of rain, snow, and wind for the Upper Midwest.
Deer hunters here in MN sure are loving the mild weather. Was like this last year as well. Got 2 hanging in the garage right now that need to be cut up. Good stuff!
The severe winter of 77/78 played a large part in the countries economic problems in the late 70’s and early 80’s. It basically shut down a large part of the country for an extended period of time, and the shipping delays and extra costs associated with it had major impacts on private citizens, companies and governments. It was the straw that broke the camels back in some cases for people that were just hanging on financially.
U.S. inflation rate had been above 6% since early in the year of 1977. In September of 1978 it went over 8% and finally broke through the psychological barrier of 9% after the Ohio blizzard. There was a major scramble for coal and heating oil that winter as I recall, and it helped push inflation up due to the panic demand for heating energy. As a result inflation spiked sharply upwards for the next few months, going into the double digits in 1979.
Although there were plenty of other contributing factors, the bitter cold weather and strangled transportation due to blizzards and heavy snow was the final blow for many companies and individuals who were just barely hanging on financially.
I remember news stores about depleted coal stock piles at power stations and how many days of coal they had on hand if they did not get any other shipments.
This was due both to the weather and to a 110-day national coal strike in the United States December 6, 1977 – March 19, 1978.
Larry
scott says:
November 10, 2010 at 8:42 am
Scott, if you haven’t already, please read this:
http://www.docksidereports.com/rough_water_seamanship_1.htm
Live version here
Eyes Wide Open:
‘Obviously a thoughtful man but I never got a sense anyway that that line in the song was placing any blame on anyone!’
Agreed, my view is that he was telling us how puny and powerless humans are against the power of nature. There are some environmentalists and warmist scientists who should listen to that song and find some humility, especially the current crop of geo-engineers.
=========================
scott: ‘Seems like long relatively thin boats like oreboats are particularly susceptible to this. …. Got me thinking that I had no idea what mechanisms actually sinks boats (other than holes) so how could I be prepared to stop it from happening.’
And this got me wondering about how the typical lean Viking warship, long and fairly narrow, was designed to be flexible and resilient in conditions just like this. Their normal trading ships were somewhat tubbier and higher sided but still used very similar construction methods. Obviously, they were much smaller and built of wood (a benefit in this purpose and a source of the flexibility) but those Scandinavians had clearly learned by bitter experience what worked best in the twisting seas scott mentions. Did the loss of ships like the Edmund Fitzgerald contribute to any changes in fundamental design?
I forgot a note in my last comment…
> As in most endeavors, various weather services and others have learned much from mistakes or events that expose problems.
I finished this post at 0200 local time. One reason for the late finish is that I attended a CoCoRaHS (Community Collaborative Rain, Hail and Snow Network) training session last evening. Their goal is to provide a high density network of volunteer observers reporting data for hydrologic forecasts and related stuff. The trigger for its formation was a 1997 flash flood in Fort Collins that cleared out a canyon of roads, bridges, and several homes. The rainfall total was some 12 inches, but the existing NWS network completely missed it.
In general in storm conditions merchant vessels sink from one of three causes:
The hatchcovers give way and the ship floods.
The righting lever proves inadequate so the ship capsizes: often prompted by a shift in the cargo.
The hull breaks up almost always in torsion rather than hog or sag.
Bulk carriers are at greater risk than other designs and although little reported or noticed by the MSM the industry loses about one a week. It is a scandal in which the yards blame the owners for cutting costs the owners blame the cutthroat market, and so on but in the end both cargo and bottom are insured so the only losers are the families of the poor sailormen who are lost.
I suspect the Edmund Fitzgerald’s unusual design would have made her particularly vulnerable in very heavy seas: for which, bearing in mind her intended use, she may not have been designed.
Kindest Regards
My grandfather and two of my uncles were out on the Mississippi for the “Armistice Day” storm. They made it to safety when many did not, mostly I suspect because my grandfather, who trapped and fished commercially on the river for more than fifty years, was the wiliest and most knowledgeable river hand I or any of the people that knew him ever met. If you were on the river with him and he got that look and said it’s time to head in, everybody got right to stowing away gear, no matter how benevolent the conditions appeared at the moment.
In subsequent years when the conversation turned to the latest attempts of Minnesota weather to erase us all from the face of the Earth, the benchmark by which they were measured was always “Armistice Day” and something about the look around their eyes told you that this was not just the usual “you young folks don’t no what tough is” hyperbole.
Minnesota folks have a lot of respect for the weather. Mostly because around here, for most of the year, it is capable of doing something that will kill you if you’re not paying attention. My Minnesota heritage is probably why I find the climate alarmists’ doomsaying to be much less than compelling. If changing weather and climate really do pose an existential threat to humanity and the world, Minnesota would have turned into a ghost town years ago.
Does that imply that long super tankers and similar ships, which are long compared to wave lengths in a severe storm, should in addition to the normal box like right angle bulkhead/rib and deck construction, include diagonal ribs running around the hull designed to resist torsion loads?
Larry
Alexander K, one should mention that the Wahine was not just ” capsized by the ferocity of a sudden storm”, but rather had suffered significant damage from grounding on Barrett’s Reef on the way into Wellington Harbour (a longer story, but basically she was of a design that only really maneuvered well under high power settings, and the captain had for some reason reduced speed considerably on the approach to the harbour, and the ship was pushed sideways by a combination of wind and waves towards the reef and didn’t respond in time because of the reduced speed). With the damage to the hull, she was unable to keep the water levels down and that started to affect power until all power was lost. Then as the water continued to flood in, she lost stability as ships do in such circumstances, and she went over.
FWIW, the winds in the Wahine storm peaked at over 200 km/h, with an estimated central pressure around 964 HPa. It was a particular type of storm, where a tropical cyclone (Hurricane), re-intensified in the extra-tropics to become a damaging storm of hurricane proportions. Waves of over 12 metres, and a storm surge of 0.7 metres were experienced. Not unique, but caused the greatest loss of life.
@ur momisugly a jones,
You are absolutely right about the Edmund Fitzgerald and other merchant ships.
One additional factor here is that a cargo of iron ore will absorb some water, but once it gets too wet it will start to behave like a very heavy liquid. The free surface effect of iron ore sloshing around can capsize or sink any ship. Happened a few years ago on the northern Baltic Sea, too.
<>
interessante, ma i don’ la t parla italiano.
pozzo – babelfish fatto
Eric (skeptic) says:
November 10, 2010 at 9:58 am
I was wondering why the 28.05 was second place to the 28.20 storm. I guess Canada isn’t part of the U.S. after all.
The U.S. is like Sydney, if it hasn’t happened there. it hasn’t happened anywhere.
..Eyes Wide Open says:
The strange thing is that if I had listened to this song 35 years ago (maybe I did) I would have thought, what is this crap. Now I find myself actually enjoying the song and have played it twice already. Middle/Old age can have a good side. And no, I’m not trying to detract from the tragedy and I’m even typing this from on-board my boat. Hatches caving in is not the same as hatches left open, ask any sailor.
Phil
I was working at a ski resort in upper lower Michigan and remember the storm of 78. I saved the isobar reading from an ink barometer that showed a ‘north american low’. I remember going in to work from the employees quarters to the closest lodge (maybe a quarter mile) and had to struggle on my hands and knees for about 40 minutes to make it to work. Glad I started early to get in at midnight.
As a student at Northwestern Michigan College I was also fortunate enough to attend GL concert at our school where he donated his performance fee to the NMC Maritime Academy that had a graduate on the Fitzgerald. Great memories.
I lived in Dagenham near London, during the 1987 storm. Sad to say, I slept through it, but the aftermath next day was unbelievable.
My house was one of only ten in the estate that I lived in that escaped with the roof tiles still intact. I was working beside Hyde Park at the time, and I’ll never forget the amount of trees that had been uprooted, some of them 200 years old. Very sad, but awesome.
Alexander K mentioned the “Wahine Storm,” also called Cyclone Giselle, and Ed Snack referred to it as the worst storm to hit New Zealand in the 20th century, but that latter title belongs to an earlier, un-named cyclone of feb 2-3 1936.
The on-line Te Ara Encyclopedia ( http://www.teara.govt.nz/en/weather/4 ) mentions some of the following details about this great storm.
“Worst storm of the 20th century
The cyclone of February 1936 was probably the most destructive storm to hit New Zealand in the 20th century. The depression that crossed the North Island on the second and third of February 1936 brought widespread heavy rain, causing every major river in the North Island to flood. The Mangakāhia River in Northland rose by 19 metres.
Two people died of hypothermia in the Tararua Range north of Wellington where, at the height of the storm, trees were uprooted from ridges and thrown into valleys. In Auckland 40 boats were sunk or driven ashore in the Waitematā Harbour, and several more sank in the Manukau Harbour.
Disaster was narrowly averted when the interisland ferry Rangatira steamed onto rocks on Wellington’s south coast. After being stuck fast for 20 minutes, the Rangatira was able to reverse off, then turn and back slowly up the harbour.”
My home town of Palmerston North bore the brunt of this storm. One of those who perished of hypothermia was from here. Northern Hemisphere readers need to remember that February is the only month of the year that snow doesn’t appear on the Tararua Ranges (ave height is 5,000 ft). There are still river valleys in those mountains where you can find log dam remnants from that storm now!
Since records began here in June 1928, February 1936 was the wettest February with just under 200mm until the ‘month of storms’ came along to take out supreme first place with 303mm, and that was Feb 2004!
Cheers
Coops
Roy Spencer says:
November 10, 2010 at 9:49 am
Dave Wendt says:
November 10, 2010 at 1:46 pm
Excellent posts gentleman !!
hotrod ( Larry L ) says:
November 10, 2010 at 1:59 pm
Yes. Forms of geodetic/geodesic hull construction have been known in their modern form for at least 300 years and make for an immensely strong hull but they are expensive to build. The pressure on cost being what it is merchant ships are generally built to the just good enough standard. And loaded to it too, forget the Plimsoll line, the industry has steadily pressed for and got increased load limits over the last hundred years.
This makes such ships marginal in adverse conditions. And nothing sinks faster than a bulk carrier loaded with heavy ore whereas a tanker full of oil can float in pieces for a considerable time.
Thus the naval architects will avoid raising the metacentric height, which improves the effect of the righting lever, above the bare minimum for stability because this requires a considerable increase in structural strength and thus steel and thus cost.
For the same reason diagonal bracing is disliked because it adds to the build cost: the preferred solution is to increase the size of the longerons along the bottom of the hull to resist the torsional load.
The importance of keeping constant torsional rigidity along the length of very fine, long and thin, hulls has been known for over a hundred years because otherwise the two ends of the hull may oscillate at different frequencies causing massive stresses to build up between them at the effective point where they meet: which is where the hull fails.
An example of this was MV Kowloon Bridge which broke in two about 25 years ago at exactly the point where the builders, Swan Hunter, had, for reasons of cost and difficulty in construction had replaced the originally intended full length longerons by cutting them off short at the bridge and substituting a complex framework aft.
She was near sister of the MV Derbyshire lost a few years earlier and after this hull failure everybody assumed that the loss of MV Derbyshire was due to the same fault but further enquiry showed it not to be so. In fact MV Derbyshire had been built to the original specification and did not break up in torsion, rather she foundered due to a progressive failure of the forward hatch covers.
It is not unusual for a hull to break in two as the vessel founders because the stresses on it as it sinks vastly exceed those it was designed for so it is quite usual to find the wreck in two parts.
Where vessels become very long compared to the wavelengths they encounter in heavy seas various other problems arise, chiefly that it is difficult to know what may happening at the bow from the bridge aft, in the early days of plateau size tankers, typically around 330,000 tonnes DWT and carrying about 250,000 tonnes of crude, going around the Cape the crew could be left in blissful ignorance of quite severe damage to the bow: because the hull’s motion no longer responds to the waves increasing wave impact. Likewise, unless below deck access is provided it is impossible for the crew to assess, check or rectify a failure forward: it is notable that MV Derbyshire did not have any such companionway. Today most designs provide for these problems.
I have not read the reports on the loss of the Edmund Fitzgerald, but given her degree of fineness I imagine her designers would have been well aware of the torsional problems. But again given her plying limits they might have underestimated the moments produced along the hull by a severe storm: not least because as an enclosed lake with quite a long fetch the seas would have been both short and steep.
Whatever did happen it is clear that the catastrophe overwhelmed the crew so quickly that they had no chance either to avert it or escape.
Kindest Regards.