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Author Topic: The Dole Derby  (Read 121943 times)

Gary LaPook

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Re: The Dole Derby
« Reply #90 on: March 17, 2012, 07:25:53 PM »

For those who did not load the Google Earth ocean current file you can play a Video instead. You can save the video to your hard drive by right clicking the Video link and then select "Save Target As" or "Save Link As" depending on the browser.
How did you capture that video from Google Earth?

gl
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Heath Smith

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Re: The Dole Derby
« Reply #91 on: March 17, 2012, 07:37:11 PM »


I took screen shots and manually edited each frame in Adobe Photo Shop. I created 72 layers then compiled them in to an automated .GIF then converted them to an .mpeg. The process required about 4 hours to complete.

Ok, not really ;D. A friend recently told me about this package called Applian Replay Capture Suite. They have a fully functional demo that can capture audio and video streams. Anything that can be displayed on the monitor can be captured. The one that I used is their video capture program that can also capture audio as well. You need a decent processor to keep up if you are recording something like live video. I need something to record video conferences at work so I will probably buy the full retail version for about $80. It is a good deal if you have a need to capture or convert video and audio.
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Harry Howe, Jr.

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Re: The Dole Derby
« Reply #92 on: March 18, 2012, 12:03:34 AM »


Gary
The last sentrence in a paragraph under the heading Seamanship in the manual reads "You can't go very far in a raft." (emphasis mine hjh).  The manual was dated November 1961, 17 years after Zamperini and Phillips went 2000 miles in a raft.  Perhaps the writers of the official survival manual hadn't heard of them (Z&P)? Perhaps it was inter-service rivalry, i.e. Air Force in '61 versus Arny Air Corps in 1944.?  What else might the manual writers have missed about rafts and currents and winds and paddles and sails?

No, I am not a sailor but I have heard of the Lateen sail,which was developed long ago to enable a craft to sail against the wind by "tacking" which I take to mean that the sail acts like a vertical "wing" with a camber that creates a force behind and into the sail thus propelling it forward against the wind in a zig-zag path.  I believe the Arabs invented it to propel their dhous.
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Gary LaPook

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Re: The Dole Derby
« Reply #93 on: March 18, 2012, 01:18:43 AM »

More than likely the animation consists of 72 frames and there is no relation to time. I am not sure why you believe there is an illusion of some sort. The colors are only intended to give you a relative notion of the velocity. This is more than likely a model as the description states. This is not intended to give you a radar like image but an idea of the direction and rate of the currents. If you check this image you can see the direction and the speed of the currents. In the region of interest, the current appears to be moving at a rate of about 2 Knots to the West.

While the trade winds would have a major effect we do not know anything about the winds at the time of the disappearance. It is quite likely that the prevailing winds were from the North-East or East in that region of the pacific. Where did you get the South-East wind from?
The current chart that your link takes us to is dated 1943 and the pilot charts I posted are dated more than 50 years later. The general rule is that you use the more modern data as it is likely to be  more complete and also obtained with more precision so resulting in  more accurate information. Did you ever consider where the data came from that was used to draw your 1943 chart? No satellites, right? Well it was obtained from reports sent in by ships' captains and by examination of ships' logbooks. This presents two problems with the data set used in 1943. First is the paucity of such data for the area in question since it is not on a well traveled shipping lane. Look at the pilot chart which depicts shipping lanes, none pass within a 1,000 miles of this part of the ocean. When you are in the middle of the ocean away from shipping lanes, the ocean is a lonely place. In 2009 we sailed from Lisbon to Barbados via Tenerife in the Canaries. After leaving Tenerife the next ship we saw was tied to the dock in Barbados, ten days later. Tenerife to Barbados is not on a standard shipping lane today but it was a traditional route during the days of sail. The standard advice for sailing from Europe to America was "sail south 'til the butter melts before turning west." Going south gets you to the latitudes of the trade winds which then drives your ship straight downwind to the Caribbean. So most of the data used for your chart came from whaling ships that hunted whales in that area during the 19th century, data that was a hundred years old.

This brings us to the second problem with the data set used for the 1943 chart, its lack of accuracy. To determine the currents accurately requires accurate navigation positions and the methods used in the 19th century lacked the precision of today. When asked about thecare they used in navigating their whalers, New England whale captains commonly answered "I don't care where I am as long as I am surrounded by whales."

So the modern pilot chart I posted has a much larger and precise data set so these charts are more accurate than the 1943 chart and it gives the current in the area where Doran is presumed to have gone down as only 0.7 knots.

gl

gl
« Last Edit: March 18, 2012, 02:19:51 AM by Gary LaPook »
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Gary LaPook

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Re: The Dole Derby
« Reply #94 on: March 18, 2012, 02:03:11 AM »


Gary
The last sentrence in a paragraph under the heading Seamanship in the manual reads "You can't go very far in a raft." (emphasis mine hjh).  The manual was dated November 1961, 17 years after Zamperini and Phillips went 2000 miles in a raft.  Perhaps the writers of the official survival manual hadn't heard of them (Z&P)? Perhaps it was inter-service rivalry, i.e. Air Force in '61 versus Arny Air Corps in 1944.?  What else might the manual writers have missed about rafts and currents and winds and paddles and sails?
That was a very exceptional case, the record before that had been 21 days set by Rickenbacker and his crew. What the manual is telling people on a raft is "don't expect to be able to equal Zamperini's experience," which is accurate advice. Since the Air Force is the direct descendant of the Army Air Corps and the Army Air Forces, I don't think inter-service rivalry is a factor, there were many people in the Air Force in 1961 who had previously served in the Army Air Forces during WW2. Now if Zamerini had been a naval swabby......
Quote

No, I am not a sailor but I have heard of the Lateen sail,which was developed long ago to enable a craft to sail against the wind by "tacking" which I take to mean that the sail acts like a vertical "wing" with a camber that creates a force behind and into the sail thus propelling it forward against the wind in a zig-zag path.  I believe the Arabs invented it to propel their dhous.
A modern, well designed sailboat with a tall, high aspect ratio sail plan can sail within 45 degrees of the true wind. Square rigged vessels could only sail within about 70 degrees of the true wind so do not make much progress against the wind. But what makes sailing upwind possible is a keel that acts like a hydrofoil making lift under water.  So it was not the lateen sail that made sailing close to the wind possible but that in combination with the keel. Life rafts do not have tall sails (if they have sails at all) and they do not have keels which is why they can only sail about straight downwind, more than 170 degrees away from the true wind for large rafts and straight downwind for a small raft. The sail and keel combination extracts energy out of the air/water system which propels a sailboat. A balloon cannot extract energy from the movement of the air mass, the wind, it can only travel with the air mass, straight downwind, just like a life raft. A windmill can extract energy from the  movement of the air because it is anchored to the ground and cannot be blown downwind and a sailboat, with a keel which prevents the boat from being blown straight downwind, can also extract energy from the movement of the air at the interface with the ocean and so be propelled in about 3/4ths of the compass, only excluding the 90 degrees surrounding the direction of the true wind.

gl

« Last Edit: March 18, 2012, 02:29:48 AM by Gary LaPook »
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Heath Smith

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Re: The Dole Derby
« Reply #95 on: March 18, 2012, 05:52:55 AM »

Quote
So the modern pilot chart I posted has a much larger and precise data set so these charts are more accurate than the 1943 chart and it gives the current in the area where Doran is presumed to have gone down as only 0.7 knots.

As the NASA model shows the currents are much more dynamic and complex than what can be captured on a chart that shows general trends. Irrespective of the current, as you had stated about Zamperini's experience, the wind was the major factor, not the current. There are a lot of variables here and I do not believe that you can accurately predict which direction and how far an object would have traveled back in 1927 in the region of the Pacific. If you can, please tell me the lotto numbers for Tuesdays drawing in Michigan Mega-Millions this coming Tuesday, the jackpot is going to be 250 million and I could really use the cash.
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JNev

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Re: The Dole Derby
« Reply #96 on: March 18, 2012, 09:10:58 AM »

Good point, Heath -

Anyone who can accurately figure the odds of bumping into one of these islands - or not doing so (even though we can see it's 'remote') - in a given circumstance ought to be rich beyond measure by sopping up lotto loose change week-after-week...

And if they are, I wish they'd step up and fund more searching at Gardner.

LTM -
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Harry Howe, Jr.

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Re: The Dole Derby
« Reply #97 on: March 18, 2012, 11:05:15 AM »


I wonder what a fishing boat captain off the coast of Japan, about a year ago, with his pilot charts (is that what they are called, pilot charts?, that's the ticket, just kidding)  on his desk showing the current direction and speed in his location, thought about the large wave (40 to 60 feet in height and moving at speeds of up to 500 mph) that enveloped him.  I suppose he said something like , hey, where did you come from?  You're not on the charts!  The charts show averages, they do not show outliers or micro-currents.  We have no idea what the currents surronding Hawaii in August/September of 1927 (or, for that matter,in June, 1944) were like.

I am anxiously awaiting delivery of the book "Unbroken" by Hillebrand, the story of the Zamperini/Phillips and McNamara episode.

Another great read about a sea survival is the book "Survive The Savage Sea" by Dougal Robertson. A Wikipedia summary is at:
"Robertson, who had been keeping a journal in case they were rescued, recounted the ordeal in the 1973 book Survive the Savage Sea, which served as the ..."
http://en.wikipedia.org/wiki/Dougal_Robertson   - 34k - Cached - Similar pages
I'd make it a link but I haven't learned how to do that yet.
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Harry Howe, Jr.

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Re: The Dole Derby
« Reply #98 on: March 18, 2012, 12:06:18 PM »


Gary
A summary from  Encyclopedia Britannica online(see below for http location)
"lateen sail, triangular sail that was of decisive importance (emphasis mine, hjh) to medieval navigation. The ancient square sail permitted sailing only before the wind; the lateen was the earliest fore-and-aft sail. The triangular sail was affixed to a long yard or crossbar, mounted at its middle to the top of the mast and angled to extend aft far above the mast and forward down nearly to the deck. The sail, its free corner secured near the stern, was capable of taking the wind on either side, and, by enabling the vessel to tack into the wind, the lateen immensely increased the potential of the sailing ship.(emphasis mine, hjh)The lateen is believed to have been used in the eastern Mediterranean as early as the 2nd century ce, possibly imported from Egypt or the Persian Gulf. Its effective use by the Arabs caused its rapid spread throughout the Mediterranean, contributing significantly to the resurgence of medieval commerce. Combined with the square sail, it produced the ocean-conquering full-rigged ship. The Sunfish class of one-design sailboats is lateen gged."

http://www.britannica.com/EBchecked/topic/331395/lateen-sail   - 83k - Cached - Similar pages



On a canoeing/fishing trip on Lake Isabel in the Quetico, I fabricated a hasty lateen sail and mounted it on a mast and attached it to my smooth-bottomed 17 foot  Sears-Roebuck canoe.  We, (me, my son, and his friend, they were 14 at the time) then "sailed" up the lake with the wind, then came back to camp tacking against the wind.  Great fun but a lot of bailing cause of the lean of the canoe as we tacked into the wind.  I can see where a keel, even a small one like the one on a Grumman canoe, would have helped resist the leaning.

Hey, this is fun, almost like Dr Seuss and Oh, the places you'll go and the things you'll see!
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Gary LaPook

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Re: The Dole Derby
« Reply #99 on: March 18, 2012, 12:09:35 PM »


I wonder what a fishing boat captain off the coast of Japan, about a year ago, with his pilot charts (is that what they are called, pilot charts?, that's the ticket, just kidding)
They are named Pilot Charts.
Quote
on his desk showing the current direction and speed in his location, thought about the large wave (40 to 60 feet in height and moving at speeds of up to 500 mph) that enveloped him.  I suppose he said something like , hey, where did you come from?  You're not on the charts!


In deep water the waves that make a tsunami are not very high, only a foot or two, and they have a very long wavelength. It is only when the "feel the bottom" in shallow water do they pile up and become destructive. 
Quote

The charts show averages, they do not show outliers or micro-currents.  We have no idea what the currents surronding Hawaii in August/September of 1927 (or, for that matter,in June, 1944) were like.

Yes we do have a very good idea of what the currents and the winds were at those times and places, that information is on the pilot charts. F=MA. (Force = Mass x Acceleration so Acceleration = Force/Mass). The Mass of the water in the North Pacific Equatorial Current is approximately ten-quadrillion-zillion slugs so to accelerate that water to increase the speed of the current by even 0.1 mph (0.15 feet per second ) would take 1.5-quadrillion-zillion pounds of force. How do you come up with that force, Harry? Nukes won't do it!

You mention micro currents downstream of islands. You are a canoeist so I'm sure that you are familiar with the same type of micro currents created by rocks in a stream that cause the flowing water to go around the rocks causing whorls and turbulent flow downstream. In this turbulent flow the velocity of the water changes in direction and speed temporarily but dies off after a short distance and this is the same type of turbulent flow induced by ocean currents flowing past an island. Let me ask you this, Harry. In all of your experience as a canoeist on rivers and streams did you ever encounter a current that pushed your canoe back upstream against the prevailing current?
I didn't think so.

Look at the wind rose near the position of the presumed Doran splash point, 51% of the time the wind is from the northeast; 39% from the east; 2% southeast; 1% south; 1% southwest; 2% west; 2% northwest; 2% from the north and 0% of calms. So do we know what the winds were on the day she splashed? No, that may have been the one day out of a hundred that the wind was from the south. How about on the second day, the third? You can't be certain what the winds were on any one particular day but due to the principle of "reduction to the mean" we can be very certain, that over the long period of time that she would have had to have been adrift, that the winds she encountered were accurately represented by the wind rose, 51 days out of a hundred (or maybe during that period it might have been 50 or 52 days, but it would have been very close to 51) she would have had northeast winds, etc.
Quote

I am anxiously awaiting delivery of the book "Unbroken" by Hillebrand, the story of the Zamperini/Phillips and McNamara episode.

It' a good book.
Quote

Another great read about a sea survival is the book "Survive The Savage Sea" by Dougal Robertson. A Wikipedia summary is at:
"Robertson, who had been keeping a journal in case they were rescued, recounted the ordeal in the 1973 book Survive the Savage Sea, which served as the ..."
http://en.wikipedia.org/wiki/Dougal_Robertson   - 34k - Cached - Similar pages
I'd make it a link but I haven't learned how to do that yet.

gl
« Last Edit: March 18, 2012, 12:18:41 PM by Gary LaPook »
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Heath Smith

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Re: The Dole Derby
« Reply #100 on: March 18, 2012, 12:36:09 PM »


Speaking of books, I found this one today: Shooting Star: The First Attempt By A Woman To Reach Hawaii By Air about Mildred Doran, written by her nephew. I bought the Kindle version today for $3. Should be an interesting read.
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Harry Howe, Jr.

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Re: The Dole Derby
« Reply #101 on: March 18, 2012, 12:40:09 PM »


Gary
 "Let me ask you this, Harry. In all of your experience as a canoeist on rivers and streams did you ever encounter a current that pushed your canoe back upstream against the prevailing current?
I didn't think so."

Actually, I did, many times,  when runing a rapids and dropping thru the "V" formed by the water moving down between two good-sized rocks, and needing a rest before continuing downriver, I would  move across the shear line into the eddy current that was moving upstream behind the rock and move up until  the nose of my canoe touched the rock and the upstream moving eddy current held me there as I rested.  It's a standard maneuver when running a long class 4 rapids.  Of course I wasn't in an open aluminium canoe in a class 4 rapids, I was either in my closed canoe or my kayak.  The maneuver needed to get across the shear line and into the eddy behind the rock without overturning is tricky.  It involves "planting" the paddle in the eddy and leaning the canoe (kayak) so that the bottom is towards the eddy and then rotating about the paddle as the booat moves into the eddy.  Even trickier getting back into the main current after resting, but basically the same technique except that the main current is moving much faster than the eddy.  Turned over many times and had to do an "Eskimo Roll to get upright.  Also had to exit the canoe/kayak by falling out upside-down into the rapids and hanging onto the craft.  That's fun also.

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Gary LaPook

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Re: The Dole Derby
« Reply #102 on: March 18, 2012, 12:41:46 PM »


Gary
A summary from  Encyclopedia Britannica online(see below for http location)
"lateen sail, triangular sail that was of decisive importance (emphasis mine, hjh) to medieval navigation. The ancient square sail permitted sailing only before the wind; the lateen was the earliest fore-and-aft sail. The triangular sail was affixed to a long yard or crossbar, mounted at its middle to the top of the mast and angled to extend aft far above the mast and forward down nearly to the deck. The sail, its free corner secured near the stern, was capable of taking the wind on either side, and, by enabling the vessel to tack into the wind, the lateen immensely increased the potential of the sailing ship.(emphasis mine, hjh)The lateen is believed to have been used in the eastern Mediterranean as early as the 2nd century ce, possibly imported from Egypt or the Persian Gulf. Its effective use by the Arabs caused its rapid spread throughout the Mediterranean, contributing significantly to the resurgence of medieval commerce. Combined with the square sail, it produced the ocean-conquering full-rigged ship. The Sunfish class of one-design sailboats is lateen gged."

http://www.britannica.com/EBchecked/topic/331395/lateen-sail   - 83k - Cached - Similar pages



On a canoeing/fishing trip on Lake Isabel in the Quetico, I fabricated a hasty lateen sail and mounted it on a mast and attached it to my smooth-bottomed 17 foot  Sears-Roebuck canoe.  We, (me, my son, and his friend, they were 14 at the time) then "sailed" up the lake with the wind, then came back to camp tacking against the wind.  Great fun but a lot of bailing cause of the lean of the canoe as we tacked into the wind.  I can see where a keel, even a small one like the one on a Grumman canoe, would have helped resist the leaning.

Hey, this is fun, almost like Dr Seuss and Oh, the places you'll go and the things you'll see!
I'm familiar with the lateen sail, I've sailed sunfish and sailboards which also use a kind if lateen sail. Something you might not have noticed is that sunfish and sailboards have centerboards (called daggerboards because they slide through a slot in the hull) that extend below the water as keels, providing lateral resistance and allowing them to be sailed close to the wind.

I too have fashioned sails when crossing lakes in a canoe and I have gotten them to sail upwind because a canoe is hard to push sideways due to the shape of the hull and the long keel. But to get the best performance out of a sailing canoe I also attached "leeboards" on each side of the canoe that extended down into the water to act as a keel. If you are ever in Holland you will see traditional workboats fitted out with "leeboards" for the same purpose. Here, is a picture,  and here. You like Wikipedia. When sailing a boat equipped with a centerboard instead of a fixed keel, you lower the centerboard when sailing upwind because the lateral resistance provided by the board is necessary to allow you to sail upwind but you pull up the centerboard when sailing downwind because it is not needed then and by pulling it up you get rid of its drag.

Experience is a powerful teacher which is why, in flight training, we arrange events that teach things to the student and these lessons stick with a person and are much stronger than something read from a book or seen in a video. I believe that your personal experience in being able to sail a canoe is coloring your thinking about this point and causing you to downgrade contrary information provided by the Air Force Survival Manual as to the ability of a life raft to be sailed against the wind. I have been trying to point out that your experience does not accurately duplicate the situation in a life raft so you should give more credit to the Air Force Manual, drafted by professionals charged with the serious duty to save airmen's lives.

gl
« Last Edit: March 18, 2012, 12:58:41 PM by Gary LaPook »
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Gary LaPook

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Re: The Dole Derby
« Reply #103 on: March 18, 2012, 12:44:45 PM »


Gary
 "Let me ask you this, Harry. In all of your experience as a canoeist on rivers and streams did you ever encounter a current that pushed your canoe back upstream against the prevailing current?
I didn't think so."

Actually, I did, many times,  when runing a rapids and dropping thru the "V" formed by the water moving down between two good-sized rocks, and needing a rest before continuing downriver, I would  move across the shear line into the eddy current that was moving upstream behind the rock and move up until  the nose of my canoe touched the rock and the upstream moving eddy current held me there as I rested.  It's a standard maneuver when running a long class 4 rapids.  Of course I wasn't in an open aluminium canoe in a class 4 rapids, I was either in my closed canoe or my kayak.  The maneuver needed to get across the shear line and into the eddy behind the rock without overturning is tricky.  It involves "planting" the paddle in the eddy and leaning the canoe (kayak) so that the bottom is towards the eddy and then rotating about the paddle as the booat moves into the eddy.  Even trickier getting back into the main current after resting, but basically the same technique except that the main current is moving much faster than the eddy.  Turned over many times and had to do an "Eskimo Roll to get upright.  Also had to exit the canoe/kayak by falling out upside-down into the rapids and hanging onto the craft.  That's fun also.

That sounds like fun, but cold. Did you ever find an eddy that pushed you back upstream to where you put your canoe into the river?

gl
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Harry Howe, Jr.

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Re: The Dole Derby
« Reply #104 on: March 18, 2012, 01:09:33 PM »


Yeppers, the large rapidly moving rivers in Wisconsin in the spring can be cold.  That's why I wore a wet-suit, bootees, gloves and high-flotation life preserver.  By wearing a neoprene "skirt" stretched over the cockpit of the canoe/kayak and fastened to my waist I became a part of the craft and water couldn't get into the canoe/kayak.  Until ya turn over and have to exit the craft. But even then not a lot of water gets nto the craft cause there are air-filled flotation "bags"  fore and aft of the cockpit.

No, never encountered an eddy that long, the objective was always to get downstream as safely as possible in as challenging a river as posible without losing your life or limb or craft or "stuff".Kinda like flying, hours of boredom separated by moments of sheer terror, on ly without the boredom, LOL.
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