Jennifer Mueller
Member
hi i was wondering how big was the iceberg that sank the titanic thanks
Size of the Iceberg
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Brian R Peterson
Guest
Hi Jennifer,
While no one knows for sure how big the iceberg actually was as only a few people on board saw it and 90% of the iceberg is below water, my guess would have to be it was around 200 feet above water and about maybe 80 ft. in diameter, this is just an educated guess.
Brian
While no one knows for sure how big the iceberg actually was as only a few people on board saw it and 90% of the iceberg is below water, my guess would have to be it was around 200 feet above water and about maybe 80 ft. in diameter, this is just an educated guess.
Brian
Tom Pappas
Guest
There is a discussion over at this link.
Deborah Russes
Member
I remember reading something about icebergs (although the article had nothing to do with the Titanic) and it said that the portion above the water was either 1/3 or 1/4 (can't remember which) of the entire size of the iceberg.
Bob Godfrey
Member
When water freezes it traps air and becomes less dense, so it weighs less - about 10% less - than liquid water. That means it will float, but with only 10% of its mass above the waterline. That's the situation in fresh water. Salt water is denser and therefore heavier, and the density is also greater when the water temperature is close to freezing point. That means it can support more weight. So the proportion of an Atlantic berg above water is actually a little higher - about 14%. That's not to say that a berg which is, say, 140 feet high above the waterline will be 860 feet deep below it. Bearing in mind that the berg will be much longer and wider in the underwater portion, the height above water could well be about 1/3 or 1/4 of its full depth, top to bottom.
Yuri Singleton
Member
I would like to add a couple of things to the conversation:
1. I conducted a little experiment with ice at my home over a year ago and came up with some interesting results. The experiment wasn't very scientific, in that there were no controls or quantitative test sets with calculated variables to plot out on a graph. Simply some crude observations, but still I believe they point toward a better understanding of how icebergs behave.
First I took some different geometric shapes found around the house and filled them with water and froze them in the fridge.
I froze a long narrow cylindrical water bottle.
A shorter, wider, but still cylindrical picnic cup.
A small cubical tupperware dish.
An inverted frisbee, ice was shaped like a pancake.
And a tennis ball with hole cut into it. Formed a sphere.
Next I filled my kitchen sink with cold, very salty water. I added almost a full Morton's Salt container into the water. It actually precipitated to the bottom the water was so saturated with salt. I thought about using 'sea salt' but am much too lazy to make a special trip to the store. (Besides, illegal to drive while drinking...Not that I was drinking when I did this, but when I went to the bathroom I actually precipitated hops and barley!!! But thats another story.)
Cut the 'icebergs' out of their molds and one at a time placed them into the brine water.
The long narrow cylinder floated in a stable fashion on its side longways, like a log in a river. It did NOT float upright like a greek column in the water.
The Picnic cup berg also floated more or less longways like the bottle shape, but was less stable. It rolled and flipped over easier. It did have the greatest surface profile of all the tests. In part due to being slightly flared on one end. This flared end created a sloped ridge rising out of the water.
The cubical berg rolled around a lot. It was very unstable and easy to flip. It had the second highest surface height. And then it didn't, and then it did again...
The frisbee berg, was the most stable. It floated flatly like a life preserver, however it had almost no surface height. That is it appeared to float just under the meniscus of the water, with very little or no visible part breaking above the water surface. It also didn't remain in one piece for very long. Soon it cracked into three pieces, each remained floating flatly though.
Lastly the tennis ball behaved much like the cube, it rolled continually and was the most unstable. Its surface height was also very small.
To me, these admittedly hokey tests illustrated that ice seeks the orientation of greatest stability. In my tests, this meant that each berg tried to put as much of its mass as possible at or near the water surface. It showed that the concept of a long, columnar shaped berg floating upright with 10% of its mass above water and 90% below extending far down into the depths is false. My tests did not exhibit that behavior. My tests lead to the concept of ice trying to flatten itself out at the surface. Presenting the greatest possible surface area, or massive area, closest to the surface.
This ties in perfectly with the idea of 'ice shelfs' surrounding icebergs at sea. The shelf is the broadest face of the most massive side of the berg. Since, as in my tests, you can have a large body of ice floating only slightly submerged, any peaks extending high above water would represent only a tiny portion of the overall mass of the berg. I see it this way, icebergs don't like having big portions of themselves rising out of the water. Nor do they like having large portions of themselves extending deep below the surface. They seek equilibrium at or just shallow below the surface. This makes sense because ice floats due to having lower density than the water around it. The water attempts to push the less dense, air filled ice up and out of the water. Similarly, ice is more dense than air, and the sinks to the bottom of the atmosphere. That equilibrium point between water and air is the ocean surface. Any part of the berg that isn't right at the surface is in conflict with the forces around it.
Since the berg is constantly seeking equilibrium, as it melts, erodes or fractures over time, it will naturally tend to mill itself into the most stable form possible. Based on my tests, and on my reasoning, I predict that the most stable shape for a berg is that of a balanced cylindrical diamond floating vertically. With the majority of its mass located in the center of the body where the cylinder reaches its greatest radius, and two conic ends of equal size and shape. (Imagine two chinese WOKs welded together at their tops, or a spinning top, or two cones placed base to base and fused in that position.)
Of course in real world conditions, this perfect shape likely will never, or rarely, be seen. Icebergs are not stable objects, but are in fact examples of instability. I only propose to describe what is in my opinion how they could theoretically form in perfect conditions. It is this theoretical model I choose to use in my imagination when visualizing Titanic's collision, allision, grounding, or evasive maneuvers. Its not a perfect theory, and its origins are not scientific, but mostly observational. Not empirical.
That is the shape I imagine when I think about the berg that was seen, and contacted by Titanic.
Not a mountain of ice, 100 foot at the widest point, riding 100 feet out of the water, and extending 900 foot under the water. But rather a flatter, shallower object. Still massive, but with the majority of its mass close to the surface and forming a large surrounding shelf of submerged ice perhaps 300 feet or more in radius from the center of the peak. (Presuming the peak is near the center of the body. Who really knows?) Thus Titanic makes contact with the submerged ice as suggested in "Last Log" by Dave Brown, in a grounding situation. In my view, perhaps more of an oblique grounding, impacting first on the starboard-underbelly of the 1st cargo hold then the damage area migrating both foreward toward the forepeak and aft along the firemen's tunnel as the slope of the shelf increases in angle over event time. Until finally momentum and swing of the ship, stop the upward encroachment of the bow along the shelf slope, and the bow begins the slide off of the shelf and back off into the water. In my view, this lifting of the starboard side of the bow along the shelf created a twisting effect on the ship's structure forward of BR5. As is so well put forward by Erik and Dave in terms of structural analysis.
In this way we see that the shape and orientation of the berg is important and speaks to us of its form through the damage pattern on the ship. A berg with a wide, sloped, submerged shelf rising toward a peak which is seen above water fits well with the new theories on the ship's internal damage. And perhaps my kitchen experiments in some way illustrate the legitimacy of that imagined form.
So I caution myself and others to take these ideas with an understanding that they are only ideas and theories. I'm not a scientist and I've never been to sea, nor have I ever seen an actual iceberg in real life.
Which brings me to the second part of my post here:
For some great pictures of icebergs and information on their origins and the currents that move them, check out: uscg.mil/lantarea/iip/
Always an interesting site to visit.
Yuri
1. I conducted a little experiment with ice at my home over a year ago and came up with some interesting results. The experiment wasn't very scientific, in that there were no controls or quantitative test sets with calculated variables to plot out on a graph. Simply some crude observations, but still I believe they point toward a better understanding of how icebergs behave.
First I took some different geometric shapes found around the house and filled them with water and froze them in the fridge.
I froze a long narrow cylindrical water bottle.
A shorter, wider, but still cylindrical picnic cup.
A small cubical tupperware dish.
An inverted frisbee, ice was shaped like a pancake.
And a tennis ball with hole cut into it. Formed a sphere.
Next I filled my kitchen sink with cold, very salty water. I added almost a full Morton's Salt container into the water. It actually precipitated to the bottom the water was so saturated with salt. I thought about using 'sea salt' but am much too lazy to make a special trip to the store. (Besides, illegal to drive while drinking...Not that I was drinking when I did this, but when I went to the bathroom I actually precipitated hops and barley!!! But thats another story.)
Cut the 'icebergs' out of their molds and one at a time placed them into the brine water.
The long narrow cylinder floated in a stable fashion on its side longways, like a log in a river. It did NOT float upright like a greek column in the water.
The Picnic cup berg also floated more or less longways like the bottle shape, but was less stable. It rolled and flipped over easier. It did have the greatest surface profile of all the tests. In part due to being slightly flared on one end. This flared end created a sloped ridge rising out of the water.
The cubical berg rolled around a lot. It was very unstable and easy to flip. It had the second highest surface height. And then it didn't, and then it did again...
The frisbee berg, was the most stable. It floated flatly like a life preserver, however it had almost no surface height. That is it appeared to float just under the meniscus of the water, with very little or no visible part breaking above the water surface. It also didn't remain in one piece for very long. Soon it cracked into three pieces, each remained floating flatly though.
Lastly the tennis ball behaved much like the cube, it rolled continually and was the most unstable. Its surface height was also very small.
To me, these admittedly hokey tests illustrated that ice seeks the orientation of greatest stability. In my tests, this meant that each berg tried to put as much of its mass as possible at or near the water surface. It showed that the concept of a long, columnar shaped berg floating upright with 10% of its mass above water and 90% below extending far down into the depths is false. My tests did not exhibit that behavior. My tests lead to the concept of ice trying to flatten itself out at the surface. Presenting the greatest possible surface area, or massive area, closest to the surface.
This ties in perfectly with the idea of 'ice shelfs' surrounding icebergs at sea. The shelf is the broadest face of the most massive side of the berg. Since, as in my tests, you can have a large body of ice floating only slightly submerged, any peaks extending high above water would represent only a tiny portion of the overall mass of the berg. I see it this way, icebergs don't like having big portions of themselves rising out of the water. Nor do they like having large portions of themselves extending deep below the surface. They seek equilibrium at or just shallow below the surface. This makes sense because ice floats due to having lower density than the water around it. The water attempts to push the less dense, air filled ice up and out of the water. Similarly, ice is more dense than air, and the sinks to the bottom of the atmosphere. That equilibrium point between water and air is the ocean surface. Any part of the berg that isn't right at the surface is in conflict with the forces around it.
Since the berg is constantly seeking equilibrium, as it melts, erodes or fractures over time, it will naturally tend to mill itself into the most stable form possible. Based on my tests, and on my reasoning, I predict that the most stable shape for a berg is that of a balanced cylindrical diamond floating vertically. With the majority of its mass located in the center of the body where the cylinder reaches its greatest radius, and two conic ends of equal size and shape. (Imagine two chinese WOKs welded together at their tops, or a spinning top, or two cones placed base to base and fused in that position.)
Of course in real world conditions, this perfect shape likely will never, or rarely, be seen. Icebergs are not stable objects, but are in fact examples of instability. I only propose to describe what is in my opinion how they could theoretically form in perfect conditions. It is this theoretical model I choose to use in my imagination when visualizing Titanic's collision, allision, grounding, or evasive maneuvers. Its not a perfect theory, and its origins are not scientific, but mostly observational. Not empirical.
That is the shape I imagine when I think about the berg that was seen, and contacted by Titanic.
Not a mountain of ice, 100 foot at the widest point, riding 100 feet out of the water, and extending 900 foot under the water. But rather a flatter, shallower object. Still massive, but with the majority of its mass close to the surface and forming a large surrounding shelf of submerged ice perhaps 300 feet or more in radius from the center of the peak. (Presuming the peak is near the center of the body. Who really knows?) Thus Titanic makes contact with the submerged ice as suggested in "Last Log" by Dave Brown, in a grounding situation. In my view, perhaps more of an oblique grounding, impacting first on the starboard-underbelly of the 1st cargo hold then the damage area migrating both foreward toward the forepeak and aft along the firemen's tunnel as the slope of the shelf increases in angle over event time. Until finally momentum and swing of the ship, stop the upward encroachment of the bow along the shelf slope, and the bow begins the slide off of the shelf and back off into the water. In my view, this lifting of the starboard side of the bow along the shelf created a twisting effect on the ship's structure forward of BR5. As is so well put forward by Erik and Dave in terms of structural analysis.
In this way we see that the shape and orientation of the berg is important and speaks to us of its form through the damage pattern on the ship. A berg with a wide, sloped, submerged shelf rising toward a peak which is seen above water fits well with the new theories on the ship's internal damage. And perhaps my kitchen experiments in some way illustrate the legitimacy of that imagined form.
So I caution myself and others to take these ideas with an understanding that they are only ideas and theories. I'm not a scientist and I've never been to sea, nor have I ever seen an actual iceberg in real life.
Which brings me to the second part of my post here:
For some great pictures of icebergs and information on their origins and the currents that move them, check out: uscg.mil/lantarea/iip/
Always an interesting site to visit.
Yuri
Bob Godfrey
Member
Hi, Yuri. Your suggestion of a diamond shape rather than the often-depicted teardrop form does accord with research findings. Here's a link to a particular page on the same site. The illustration there has been created from a photograph, with an artist's impression of the greater mass of the berg below the surface. This is similar to the computer-generated forms shown elsewhere on the site:
How much of an iceberg is below the water?
The most interesting part of the photograph is on the waterline, which shows an undercut area of the berg at the right of the picture. This notch has been formed by wave erosion, a process faster but not much different from the normal process of erosion acting on cliff faces at the sea's edge. In time the overhang will collapse, maintaining a steep face and often (as in that particular pic) a slightly projecting and unstable 'lip' some distance above the waterline. And of course as this process is repeated an underwater platform or shelf will be created by the wave erosion, just below the surface and extending an increasing distance away from the visible portion of the berg.
How much of an iceberg is below the water?
The most interesting part of the photograph is on the waterline, which shows an undercut area of the berg at the right of the picture. This notch has been formed by wave erosion, a process faster but not much different from the normal process of erosion acting on cliff faces at the sea's edge. In time the overhang will collapse, maintaining a steep face and often (as in that particular pic) a slightly projecting and unstable 'lip' some distance above the waterline. And of course as this process is repeated an underwater platform or shelf will be created by the wave erosion, just below the surface and extending an increasing distance away from the visible portion of the berg.
Tom Pappas
Guest
Ice doesn't float because of trapped air. As (distilled) water cools, it reaches its greatest density at 39°F. As it continues to cool down to the freezing point, it expands until it is less dense than liquid water. That's why it floats. (And a good thing, too - if it continued to contract after freezing, it would sink, and our lakes and rivers would be clogged with ice on the bottom that never melted. Of course, ships wouldn't run into it, but it would cause other problems.) That maximum density at 6°C characteristic is also the reason that ponds "turn" twice a year. Look it up in a limnology text some time.
I think any conjecture on how Titanic was damaged by ice has to admit the myriad shapes in which ice occurs at sea. Sea ice, pack ice, glacial ice, all behave and change form differently over time, and any of them might have been instrumental in a way impossible to fathom.
I think any conjecture on how Titanic was damaged by ice has to admit the myriad shapes in which ice occurs at sea. Sea ice, pack ice, glacial ice, all behave and change form differently over time, and any of them might have been instrumental in a way impossible to fathom.
Yuri Singleton
Member
The reseviors in Dallas Tx used to always turn in the late summer, causing a nasty algae taste in the water. Everyone hated it, but the city promised that it was safe to drink. Very glad I'm on a well now.
Very true about the poly-morphic nature of ice Tom. Its always intrigued me about how Mr. Fleet choose to use a flat table to illustrate what he saw from the crow's nest. A table is of course flat on top. But we think of the berg in terms of a pyramid peak. Change the orientation or shape of the berg, and we change so much about how the ship, crew, and berg interacted during the impact.
The picture of the berg referenced by Bob is very cool. Even though my statements above don't really seem to be supported by the picture, the berg in the image is taller along its y axis than it is longer along its x axis, but there again we see that bergs are each unique, and unpredictable.
Thanks for the comments guys.
Yuri
Very true about the poly-morphic nature of ice Tom. Its always intrigued me about how Mr. Fleet choose to use a flat table to illustrate what he saw from the crow's nest. A table is of course flat on top. But we think of the berg in terms of a pyramid peak. Change the orientation or shape of the berg, and we change so much about how the ship, crew, and berg interacted during the impact.
The picture of the berg referenced by Bob is very cool. Even though my statements above don't really seem to be supported by the picture, the berg in the image is taller along its y axis than it is longer along its x axis, but there again we see that bergs are each unique, and unpredictable.
Thanks for the comments guys.
Yuri
Tom Pappas
Guest
It should be emphasized that any displacement of the obstacle by the collision such that fragments of it fell onto the forward well deck would be only the tip of the iceberg.
Aaron_2016
Guest
I have read reports regarding the possible true size and mass of the iceberg. They say it was significantly heavier than the Titanic and how the amount of ice below the water could have been 7 times larger than the exposed ice on the surface e.g. 60 feet above and over 400 feet below, but then I saw the video below. If the iceberg was blue and had possibly rolled over and capsized because it was top heavy, does that mean it's size below the water was nothing like 400 feet but something closer to 100 feet? Here is video of an iceberg rolling over. Is this the kind of the iceberg that struck the Titanic?
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Arun Vajpey
Member
I do not pretend to know the actual size of the iceberg that struck the Titanic but it has been estimated at around 550,000 tons. But what strikes me most is that despite its me most is that despite the metallic skeleton, by far the largest volume within a cruise ship like the Titanic is occupied by air. In fact, larger the ship, greater is the proportion of air within its structure. An iceberg on the other hand, is a completely solid structure and so in a collision between the two, it is the ship that always comes worse off. The next thing is that when a ship starts to flood, the inrushing water takes over the air spaces, which is why such a huge weight differential is created.
Samuel Halpern
Member
Aaron, don't confuse height above or below waterline with volume. I believe Arun Vajpey's estimate is about right. That's about 10 times the displacement of the vessel.
Dave Gittins
Member
We know very little about the berg, except that it was around 20 metres tall. Some years ago, I did a back of an envelope calculation that showed it may have weighed as little as 110,000 tons. At the same time, the late, great Roy Mengot used a computer that could handle complex shapes to come up with a possible weight of around 75,000 tons. These figures are in line with advice from the Canadian ice expert, Professor Stephen Bruneau, who says bergs on the Grand Banks are about 100,000 to 200,000 tons. At 42°N they are even small. The half million ton berg is only for the movies and the popular press.
Arun Vajpey
Member
Not necessarily. An iceberg is an irregular 3 dimensional object and just one measurement - height - will not give an idea of its true size. Width and especially depth, the latter not being obvious till the berg was seen "side-on" in relation to the ship would be major considerations. And of course, the fact that it was 9 times larger underwater.
