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Author Topic: The Bevington Object  (Read 256123 times)

Ric Gillespie

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Re: The Bevington Object
« Reply #135 on: November 09, 2012, 12:19:50 PM »

Based on Gary's research and findings, during the week from the time Earhart disappeared until the Navy Aerial Search, the water was never deep enough or rough enough to cause the Electra to fall off the reef, let alone twist a main gear from the structure of the aircraft.

Believe what you want but Gary's assumptions are incorrect and his "would have" methodology is fundamentally invalid.  Gary has never been to Nikumaroro.  I have, and I can tell you that big surf on the reef does not require an unusual weather event.  Some days it's calm, some days it's not - and when it's not it's no fun.  Most people don't appreciate how powerful the surf can be.  In the attached photo I'm standing near the spot where Bevington Object was.  It's low tide and the ocean is relatively calm - and I was barely able to stay on my feet.
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C.W. Herndon

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Re: The Bevington Object
« Reply #136 on: November 09, 2012, 12:40:44 PM »

For Pete's sake, I've picked out camouflaged AAA in jungle at 300' and 250 mph.

They must have been shooting tracers at you.

Heh - Heh

They were on the charts.  Knowing approximate locations helped.

If they were camouflaged and in the jungle, I still say my last comment applies if you were able to find them. :)
Woody (former 3316R)
"the watcher"
 
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tom howard

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Re: The Bevington Object
« Reply #137 on: November 09, 2012, 01:03:50 PM »

Thanks Ric, surf is one thing, as you stated. It can be rough even on calm days.

However, back to tide height, and relating that to the Bevington object, and would it be visible during the Navy flyover-

You have placed the object near or on the edge.
Gary says it was less than 6 inches deep there during the flyover. You state there was well over 2 feet there at the edge during the flyover.
Huge difference obviously.

Care to state what mistake Gary made in his calculation of tide height?


« Last Edit: November 09, 2012, 01:08:08 PM by tom howard »
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Ric Gillespie

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Re: The Bevington Object
« Reply #138 on: November 09, 2012, 01:09:59 PM »

Care to state what mistake Gary made in his calculation of tide height?

I always find it nearly impossible to follow Gary's reasoning and I feel no particular obligation to spend time checking his calculations.
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Chris Johnson

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Re: The Bevington Object
« Reply #139 on: November 09, 2012, 01:46:26 PM »

I would say the difference is:

a. is from a book

b.is from the real world (experience)

the number of vendor specific IT courses where the teacher has said "to pass the exam answer a. in the work place answer b. grows yearly
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tom howard

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Re: The Bevington Object
« Reply #140 on: November 09, 2012, 03:30:48 PM »

Ric, thanks for your reply and the pictures.
I am sure Gary will explain later,(well I hope), to resolve this tide height issue.

On a slightly different issue, since you were there when the reef was totally dry around the Bevington spot, have you photographed any particular spot that would support a landing gear and wheel? By that I mean a hole in the rock, a wide crevass, something that would allow a large assembly to stand straight up, and keep it from falling over for a substantial period of time?
Since you could barely stand up in ankle deep water, there would have to be a fairly large crack or hole in the rock to hold up the object in a vertical position.
All I have seen is photos of "potholes" in the coral surface, and those would not hold up the landing gear against that strong tide you noticed.
Any candidate "holes" you identified while on site? Are there lots of really deep holes near the reef edge that would support such an object?
Any pictures would be appreciated.
« Last Edit: November 09, 2012, 03:33:09 PM by tom howard »
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Gary LaPook

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Re: The Bevington Object
« Reply #141 on: November 09, 2012, 04:07:15 PM »

I would say the difference is:

a. is from a book

b.is from the real world (experience)

the number of vendor specific IT courses where the teacher has said "to pass the exam answer a. in the work place answer b. grows yearly

You appear to have missed an important point. It is not my computation, it is United States Navy Commander Brandenburg's computation. He computed that the height of the tide was 9 inches at 2100 Z, only one-half hour after the Lambrecht overflight. This is 43 inches lower than the height of the reef surface where the Electra is supposed to have been sitting which is at 52 inches above the tide datum, again by Brandenburg's computation. This 9 inch tide height is also only ONE INCH above the height of the edge of the reef, again by Brandenburg's computation. The only "computation" that I did was to INCREASE the height of the tide by 4 inches, up to 13 inches, to allow for the fall of the tide in the half-hour period from the time of the flyover to the 2100 Z 9 inch tide height computed by Brandenburg. This 4 inch change in the tide is the same as the 4 inch change in the height, down to 5 inches, one-half hour later at 2130 Z, again, as computed by Brandenburg. Based on your expertise in tidal studies, please explain how the tide fell only 4 inches in the half hour period between 2100 Z and 2130 Z, as computed by Brandenburg but managed to fall 67 inches   (a 17 times greater rate) in the immediately preceeding half hour period between 2030 Z and 2100 Z as required by Ric's claim that the tide was two feet above the reef (76 inches above the datum as computed by Brandenburg) at the location of the plane at 2030 Z, the time of the flyover. Please read what Brandenburg has written about the tide heights and look at HIS diagram of the reef and the datum. After your review you should see that the tide heights do not rely on my expertise (though I have been a sailor for almost 50 years and have had to work with tide tables and charts in order to sail deep draft boats through shallow passes through reefs in the South Pacific and other oceans) but are based on Commander Brandenburg's Navy officer's experience and expertise.

(BTW Chris, as long as we are at it, what is your expertise in these matters?)

gl
« Last Edit: November 09, 2012, 06:12:42 PM by Gary LaPook »
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Ric Gillespie

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Re: The Bevington Object
« Reply #142 on: November 09, 2012, 05:10:19 PM »

You appear to have missed an important point. It is not my computation, it is United States Navy Commander Brandenburg's computation.

What does that link have to do with Brandenburg's computations?

He computed that the height of the tide was 9 inches at 2100 Z, only one-half hour after the Lambrecht overflight.

You have not shown where he said that, but assuming that he did, if he said "height of the tide" he meant the depth of the water on the reef at Gardner.  It looks like you took him to mean the height of the water over tidal datum.   

Also note that the computations you quote from his list of Post-Loss Signal Statistics  are from a research paper Bob wrote in 2006 based on the best information available at that time. We did the reef height survey during Niku V in 2007 so his more recent computations, such as the tidal graph I posted earlier, had the benefit of much better information.  This is an ongoing investigation and our understanding of what happened is constantly changing as we get new and better information.

We do not take down or change research papers that have become outdated or superseded by later research because the papers and research bulletins on the website are a historical record of our work.  We try to put a warning at the top of outdated papers or bulletins but we don't always catch them all.
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Gary LaPook

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Re: The Bevington Object
« Reply #143 on: November 09, 2012, 06:14:58 PM »

You appear to have missed an important point. It is not my computation, it is United States Navy Commander Brandenburg's computation.

What does that link have to do with Brandenburg's computations?

You're right, I posted the wrong link. I went back and corrected it. Here is the correct link to Brandenburg's paper.
Quote

He computed that the height of the tide was 9 inches at 2100 Z, only one-half hour after the Lambrecht overflight.

You have not shown where he said that,

Page 4 of his study, six lines up from the bottom, where it states:

   " 9     2100-2130     9 to 5."    The "9" is in the column labeled "Day;"  the "2100-2130" is in the column labeled "GMT;" and the "9 to 5" is in the column labeled "Tide (inches.)"  The clear reading of this line is that on July 9th the tide was 9 inches at 2100 GMT reducing to 5 inches at 2130 GMT. This is confirmed by the next line which repeats that the tide was at 5 inches at 2130 GMT going down to 0 at 2230 GMT.
Quote



but assuming that he did, if he said "height of the tide" he meant the depth of the water on the reef at Gardner.  It looks like you took him to mean the height of the water over tidal datum.   

That is exactly how I took it, his inches of "tide" is above the tidal datum, not above the reef surface and there can be no dispute that this is how Brandenburg used that term. Brandenburg explains this clearly on the first page of the paper where he states that the reef surface is "52 inches higher than the Hull tidal datum. Since radio transmission required running the starboard engine to operate the generator, the 24 inch ground clearance of the Electra 10E propeller defined the highest water level that would permit operation, corresponding to a maximum tide level of 76 inches..." It is clear that his "tide level" of 76 inches corresponds to a water level over the reef of 24 inches so his "tide level" is definitely not the same as the height of the water above the reef. The two levels are separated by 52 inches, the height of the reef above the datum, so these are two different things. If this is not clear enough, we know that if the water level was 24 inches above the reef surface then no radio messages could be sent yet there are 37 messages listed in Brandenburg's table where there were messages sent when the "tide" was higher than 24 inches, including some with the "tide" as high as 57 inches.
Quote



Also note that the computations you quote from his list of Post-Loss Signal Statistics  are from a research paper Bob wrote in 2006 based on the best information available at that time. We did the reef height survey during Niku V in 2007 so his more recent computations, such as the tidal graph I posted earlier, had the benefit of much better information.  This is an ongoing investigation and our understanding of what happened is constantly changing as we get new and better information.


Did you determine that the reef surface was not 52 inches above the tidal datum? What value are you now using for the difference between the Hull island tidal datum and the surface of the reef and how did you determine that Brandenburg was wrong in using the 52 inch value? Is there another research paper showing this determination?

gl
« Last Edit: November 09, 2012, 06:59:27 PM by Gary LaPook »
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Ric Gillespie

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Re: The Bevington Object
« Reply #144 on: November 09, 2012, 06:46:05 PM »

You appear to have missed an important point. It is not my computation, it is United States Navy Commander Brandenburg's computation.

What does that link have to do with Brandenburg's computations?

You're right, I posted the wrong link. I went back and corrected it. Here is the correct link to Brandenburg's paper.

Yeah, that's the same outdated twelve year-old table.
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Gary LaPook

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Re: The Bevington Object
« Reply #145 on: November 09, 2012, 07:23:25 PM »


Quote from: Gary LaPook

You're right, I posted the wrong link. I went back and corrected it. Here is the correct link to Brandenburg's paper.

Yeah, that's the same outdated twelve year-old table.
How can it be "twelve years old" when Brandenburg's table was made in 2007, only 5 years ago? Brandenburg states that he used Hull island tidal data that he got from the U.K., is this the same data that you are now using? If so, how can your computation be different than Brandenburg's? Even if Brandenburg obtained his tidal data "twelve years ago," since it was a "hindcast" for 1937 the data should not change even if you got a new hindcast more recently. Do you have two separate and different sets of tidal data? Please post these data sets so that we can all see why you are now changing away from Brandenburg's report.



gl
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Ric Gillespie

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Re: The Bevington Object
« Reply #146 on: November 09, 2012, 07:43:24 PM »

How can it be "twelve years old" when Brandenburg's table was made in 2007, only 5 years ago?

It can't. My mistake.  It's six years old.  The table was made in 2006.  The survey was done in 2007.

Brandenburg states that he used Hull island tidal data that he got from the U.K., is this the same data that you are now using? If so, how can your computation be different than Brandenburg's?

You're not getting it. The Hull Island data didn't change.  There is and always has been only one set of tidal data. The hindcast of the Hull data hasn't changed. The only thing that changed is the accuracy of our data on the reef height at Niku.  It vastly improved when we did an on-the-ground survey in 2007.  The reef height determines the water level at any given moment. 

In 2010, based on the discovery and identification of the Bevington Object, we amended our hypothesis about where the airplane was parked.  We moved it northward and recalculated the water depth at the new location at various tidal states.  That's what the graph I posted shows.
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Gary LaPook

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Re: The Bevington Object
« Reply #147 on: November 09, 2012, 10:17:04 PM »

Brandenburg states that he used Hull island tidal data that he got from the U.K., is this the same data that you are now using? If so, how can your computation be different than Brandenburg's?

You're not getting it. The Hull Island data didn't change.  There is and always has been only one set of tidal data. The hindcast of the Hull data hasn't changed. The only thing that changed is the accuracy of our data on the reef height at Niku.  It vastly improved when we did an on-the-ground survey in 2007.  The reef height determines the water level at any given moment. 

In 2010, based on the discovery and identification of the Bevington Object, we amended our hypothesis about where the airplane was parked.  We moved it northward and recalculated the water depth at the new location at various tidal states.  That's what the graph I posted shows.
O.K. I see. So what is the height of the reef compared to the Hull tidal datum that your are using now?
gl
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Gary LaPook

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Re: The Bevington Object
« Reply #148 on: November 09, 2012, 11:22:07 PM »

Let me se if I can clear up the confusion (wish me luck).

Once we had a point of known height at Norwich City (point "A" on the attached map) we could reposition the Total Station to the beach in that area and get the height of numerous places on the reef relative to that point.  This enabled Bob Brandenburg to produce the attached chart that shows the state of the tide and the water level on the reef in the spot where we think the plane was parked while sending radio distress calls.  As you can see, the tide was about 2 hours past high tide and the water level on the reef in the spot where the plane had been (according to TIGHAR's hypothesis) was .4 meters, about 1 foot 3 inches.  The water level closer to the reef edge at the Bevington Object location was about a foot deeper - and that's assuming flat calm conditions.

I hope this clears up the confusion.
Thank you for the reef survey map, it is very illuminating. This brings up two questions, what is the height of point "a" compared to the tidal datum at Hull island and what is the relative height of the plane's location compared to point "a"?

gl
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Chris Johnson

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Re: The Bevington Object
« Reply #149 on: November 10, 2012, 02:13:16 AM »

Gary

my expertise is life!   ;D

grew up on the coast where a knowledge of things such as tide table (a good base point), local conditions (a great variable) and putting your head out of the door before you set out (belt and suspenders) set me safe for dealing with the sea.

Planes and navigation as you know i'm on permenant L plates but if you ever venture to the North Devon coast to walk the shore front PLEASE do not just rely on tide tables otherwise my sister and her coast guard friends will hopefully only be hauling your arse up the cliffs alive and on a rope not in a body bag

BTW the above statement probably wouldn't hold up in a court of law here or over there but i'm confident in my understanding of tides based on my experience and knowledge.

I'm not confident I could navigate a plane over the Caribean though :)

p.s. I don't claim in any way to be able to calculate tide tables, hindcaste or otherwise show by Math what the tide should be doing at any given date or time.
spelling without word so sorry
« Last Edit: November 10, 2012, 02:41:29 AM by Chris Johnson »
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