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Author Topic: The Question of 2-2-V-1  (Read 1093083 times)

Andrew M McKenna

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Re: The Question of 2-2-V-1
« Reply #135 on: February 15, 2014, 01:48:37 PM »

I was there, but I don't remember any of us actually prying pieces off to bring back.  We were asked to bring some samples back with the blue tint just so we could try to figure out what it was.

Keep in mind that the Idaho Electra was salvaged for the aluminum, so hardly any pieces of aluminum remain at all, and I can imagine that the salvage operations did a bit of prying and dismantling.

Andrew
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Ric Gillespie

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Re: The Question of 2-2-V-1
« Reply #136 on: February 15, 2014, 04:20:20 PM »

A little background on the history of aluminum in aircraft construction.  I wrote this for a piece about 2-2-V-1 that never got published. Now that the artifact is on the front burner I thought I'd share it.


Pure aluminum is too soft for use in load-bearing airplane parts but in 1908 an alloy of aluminum was invented by German researcher Alfred Wilm that included four percent copper, one half percent magnesium and on half percent manganese.  Patented under the trade name “Duralumin”, the new metal was nearly as lightweight and significantly more robust than pure aluminum and could be heat treated for even greater strength.  In the years immediately prior to and during World War One, frames and girders of Duralumin made possible the construction of airships of unprecedented size by the Zeppelin Luftschiffbau.  Rendered as corrugated sheet, the metal had sufficient rigidity to be used in aircraft construction and, during the war, was featured in several all-metal German aircraft produced by the Junkers company. 

With Germany’s defeat, the Aluminum Company of America obtained the rights to Wilm’s patent and began producing the alloy under the designation “17S” and in its fully heat-treated form “17 S-T”.  The most notable use of corrugated ALCOA 17S-T sheet in post-war American aircraft was in the Ford Tri-motor series.   By the early 1930s the technique of “stressed skin” construction had been developed and in 1933 the Boeing 247 and Douglas DC-1 entered service with uncorrugated skins, rivets and supporting structures made of heat treated 17S-T. 

The same year ALCOA introduced an alloy that contained the same elements as the old Duralumin but in slightly different proportions. Designated “24S-T” the new product was significantly stronger and soon replaced 17S-T in most aircraft applications.  To combat corrosion, ALCOA used a previously developed technique in which a sheet of alloy was “clad” with a thin protective layer of corrosion-resistant pure aluminum bonded to each side.  The resulting sandwich was called Alclad.   Beginning in 1934, Alclad 24ST  became the most widely used material for skins on American aircraft.  Known as “2024 Alclad” since 1954, it is still commonly used in aluminum aircraft construction.  For that reason, metallurgists at ALCOA were not able to “date” samples taken from the artifact based upon its physical composition.

Lockheed’s Model 10 Electra made its maiden flight on February 23, 1934.  The following is an excerpt from the company’s 1936 sales literature:

“The principal material used in the construction of the Electra is Alclad 24ST, a high strength duralumin (aluminum alloy) with a protective coating of pure aluminum on each side 5 per cent of the total thickness of the sheet.  This is the most advanced type of aluminum alloy that has been developed. Although its aluminum coating renders Alclad highly resistant to corrosion, every part of the interior of the airplane is painted for further protection. All of the outside surface and most of the structural elements are of this material.”


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Jeff Victor Hayden

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Re: The Question of 2-2-V-1
« Reply #137 on: February 15, 2014, 07:32:49 PM »

I wondered if the location of artefact 2-2-V-1 on the fuselage might have some impact upon how it came to be separated from the aircraft. Between stations 269 and 293 in the fuselage there is the door void. Yes these areas are strengthened to compensate for the void however, metal fatigue has a tendency to begin at the edges of areas like this.
The Electra wasn’t a pressurised cabin so that wouldn’t be a factor in metal fatigue propagation so, what other action might reproduce the constant stresses needed to induce metal fatigue?
Waves?
Wave action exerting force on the tail section probably doesn’t have enough force to cause instantaneous damage to the fuselage but, a small force applied often enough? A gradual weakening of the area around stations 269 and 293 is a good candidate for giving way first as opposed to any other part of the fuselage.
How often would this small force be applied?
Wave frequency varies a lot due to a number of factors, weather, location being a couple but a good ball park figure is somewhere between 8 and 24 per minute so I’ll leave that for you to decide and just assign the letter V to this variable. Remember also that a wave action has two movements so you will need to double your chosen number and then insert it in place of the variable V.
V x 60 Mins x 24 Hrs x 365 Days
Thereby giving you the number of times annually that the area in question has been stressed. Using a wave count I did last summer at Bournemouth (whatever happened to summer?) of 7 per minute which I need to double to 14 before going any further gives…
14 x 60 x 24 x 365 = 7,358,400 times the area has been subjected to a slight stress in one year.
It’s only a theory as to why artefact 2-2-V-1 became separated from the rest of the airframe and, it’s obviously only my opinion but, open to all to comment.




This must be the place
 
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Jerry Germann

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Re: The Question of 2-2-V-1
« Reply #138 on: February 15, 2014, 08:45:12 PM »

Finding a Fit…..

 IMHO, Artifact 2-2-V-1 may not fit the suggested area;

As mentioned;
 
A word of caution.  The overlay in that photo cannot be considered exactly to scale.  There are problems with perspective.  The photos of the artifact was taken from almost directly overhead and the photo of the belly structure of c/n 1052 is slightly oblique.  There is also the problem that the artifact was deformed when it was blown out.   The photo does show, however, that we're in the ballpark.  The actual match up might be even better.

Looking at this image, http://tighar.org/wiki/File:DSCN3623-overview-artifact.jpg it appears that the artifacts image may be roughly 75-80% of its actual size, as one can see by the tape measurements, it appears to be roughly 14-15 inches in width , in actuality the artifact  is 19 inches wide..23 inches in length , …..as noted, the image isn’t exact ,however ;if the artifacts  image were scaled to actual proportions  would not the rivet hole alignment shift?

This image http://tighar.org/smf/index.php?action=dlattach;topic=1426.0;attach=7228;image shows us the belly pan stringer widths on the existing c/n 1052 Electra, (Lockheed technicians have in the past stated that the Earhart Electra had 3” rivet spacing here),.. note the stringers are about 4-4 1/4  inches apart outside edge to outside edge, again note that the tape shows a beginning rivet hole spacing at (half the width of the stringer)or ½” and ending at 3 and 3/4s….for a rivet hole spacing of 3 to 3 and 1/4”  inches….this evidence seems to back that statement by former Lockheed employees.

Artifact 2-2-V-1 in the image below has been described as having a 4 to 4 and1/4 rivet spacing width. This is verified by the dimensions noted.   
http://tighar.org/wiki/File:2-2-V-1_interior_CAD.png


As stated, it does not appear that there was damage to the stringers in this area, and it is assumed they were left as per original.

Any major repositioning of stringers would require special engineering drawings mentioned in the Repair Orders and approved by the Bureau of Air Commerce. Such drawings were mentioned in the Repair Orders for strengthening splices on the nacelle ribs (where the landing gear had failed) and the subject special engineering drawings are part of the repair record.  The Repair Orders call for replacement of the skin of which 2-2-V-1 seems to be a part but no drawings are mentioned, so we must presume that the stringers didn't move much, if at all.

That  said, wouldn’t we expect the replacement panel  here, to bear a 3 inch rivet spacing?
And correct me if I am wrong, but when I look at this artifact installed here on the starboard side , it seems the artifacts rivet spacing narrows at the wrong end ( if the panel were installed in that position), and if I am looking correctly at the image in its suggested position ,it seems that  the two exterior rivet lines close at the end designated as the nose end…the innermost line stays pretty consistent , as would be expected as it is almost center belly.
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Adam Marsland

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Re: The Question of 2-2-V-1
« Reply #139 on: February 15, 2014, 10:15:46 PM »

I have a question, forgive me if it's been addressed (I did look for it throughout this thread)?

I think you've got a pretty strong case that it's from AE's plane.  But does it support the Niku hypothesis directly?

I guess what I mean is:  could it have separated in a crashed-and-sank scenario and then washed up on shore?  99% of people looking at the AE controversy would agree that she most likely came to grief within, say, a 400 mile radius of Niku.  Could she have taken a dive somewhere around Baker and this bit of crash debris washed ashore, where natives scavanged and repurposed it?
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Greg Daspit

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Re: The Question of 2-2-V-1
« Reply #140 on: February 15, 2014, 11:43:01 PM »

These photos of 2-2-V-1 were taken under low angle lighting to accentuate the bends, bows, wrinkles and dents.  It is one beat up piece of metal.
The notations of nose and tail reference how the piece appears to fit on NR12060.  We, of course, don't really know the nose/tail orientation of the piece but the rivet lines do taper slightly toward what was probably the tail.

The four edges of the piece have been numbered for ease of reference.
The labels on the two images are confusing. Look at the one labeled interior. The tab is on the left as viewed from what is labeled the nose edge. Shouldn't it be on the right as viewed from the nose in the interior? The tab should be on the keel right? I think the nose and tail are labeled wrong on both. See the 2 images along side the overlay you did on the upper right here. Either the overlay is wrong or both of these images are labeled wrong.
3971R
 
« Last Edit: February 16, 2014, 12:07:42 AM by Greg Daspit »
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Ric Gillespie

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Re: The Question of 2-2-V-1
« Reply #141 on: February 16, 2014, 08:27:33 AM »

I wondered if the location of artefact 2-2-V-1 on the fuselage might have some impact upon how it came to be separated from the aircraft.

Yes, the location is probably significant but the only part of the artifact that failed from fatigue is the bent edge.  The bending back and forth that caused that edge to fail must have occurred after the other three edges fractured due to events involving great force.  In other words, the failure of three edges created a flap of skin that cycled back and forth due to either wave or humans action and ultimately failed from fatigue.
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Ric Gillespie

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Re: The Question of 2-2-V-1
« Reply #142 on: February 16, 2014, 08:43:22 AM »

Could she have taken a dive somewhere around Baker and this bit of crash debris washed ashore, where natives scavanged and repurposed it?

Sheets of aluminum don't float worth a darn so in order for the piece to wash ashore anywhere it must have ended up in water shallow enough for wave action to move it - no deeper than about 50 feet would be a good guess.  Another indication that it was once in relatively shallow water are the spots of coral growth on the surface of the artifact.  Coral only grows in sunlit water.

All of the islands in the South Central Pacific are surrounded by reefs with steep slopes.  For the Electra to crash and sink in water shallow enough for non-buoyant wreckage to wash up onshore it would have to crash and sink right up tight to the island, but why would you crash and sink in the ocean right beside an island?
BTW, there were never any "natives" on Baker.
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Tim Mellon

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Re: The Question of 2-2-V-1
« Reply #143 on: February 16, 2014, 09:01:12 AM »

Another indication that it was once in relatively shallow water are the spots of coral growth on the surface of the artifact.  Coral only grows in sunlit water.



So, Ric, how do you explain all that coral you see at depth 985 feet?

Tim
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Martin X. Moleski, SJ

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Re: The Question of 2-2-V-1
« Reply #144 on: February 16, 2014, 09:21:11 AM »

So, Ric, how do you explain all that coral you see at depth 985 feet?

This article explains that the volcano subsides over time (p. 9), carrying dead coral down with it as new coral grows where there is sufficient light and oxygen (the top 50 meters, p. 7).
LTM,

           Marty
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Tim Mellon

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Re: The Question of 2-2-V-1
« Reply #145 on: February 16, 2014, 09:43:06 AM »

So, Ric, how do you explain all that coral you see at depth 985 feet?

This article explains that the volcano subsides over time (p. 9), carrying dead coral down with it as new coral grows where there is sufficient light and oxygen (the top 50 meters, p. 7).

Marty, I think you are completely misinterpreting what that article is saying. What subsides is that part of the volcano near the surface, not the entire cone that sits on the sea-bed. The coral then spreads inward towards where the center of the volcano was located, creating the roughly circular atoll, usually with some central lagoon.

Tim
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Martin X. Moleski, SJ

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Re: The Question of 2-2-V-1
« Reply #146 on: February 16, 2014, 10:05:43 AM »

Marty, I think you are completely misinterpreting what that article is saying.

It's the author's fault.

He is the one who wrote, "During the volcano's period of activity, the ocean floor beneath it rose, probably as a result of the pressures associated with he fusion process which generates the lavas, but as soon as the volcano died, it started sinking under its own weight, a phenomenon called subsidence which, in this area, proceeds at a rate of 1 cm per hundred years."

You should write him and tell him that he completely misunderstands the reality of atoll formation.  Shame on him!
LTM,

           Marty
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Ric Gillespie

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Re: The Question of 2-2-V-1
« Reply #147 on: February 16, 2014, 10:10:16 AM »

Finding a Fit…..

 IMHO, Artifact 2-2-V-1 may not fit the suggested area;

Okay.  Let's examine the facts upon which you base your opinion.

As mentioned;
 
A word of caution.  The overlay in that photo cannot be considered exactly to scale.  There are problems with perspective.  The photos of the artifact was taken from almost directly overhead and the photo of the belly structure of c/n 1052 is slightly oblique.  There is also the problem that the artifact was deformed when it was blown out.   The photo does show, however, that we're in the ballpark.  The actual match up might be even better.

Looking at this image, http://tighar.org/wiki/File:DSCN3623-overview-artifact.jpg it appears that the artifacts image may be roughly 75-80% of its actual size, as one can see by the tape measurements, it appears to be roughly 14-15 inches in width , in actuality the artifact  is 19 inches wide..23 inches in length , …..as noted, the image isn’t exact ,however ;if the artifacts  image were scaled to actual proportions  would not the rivet hole alignment shift?

Yes, but as I explained in the paragraph you quoted, scaling the photo to accurate proportions is not possible.  The overlay is an indication that the pattern is in the ballpark - nothing more.


This image http://tighar.org/smf/index.php?action=dlattach;topic=1426.0;attach=7228;image shows us the belly pan stringer widths on the existing c/n 1052 Electra, (Lockheed technicians have in the past stated that the Earhart Electra had 3” rivet spacing here),.. note the stringers are about 4-4 1/4  inches apart outside edge to outside edge, again note that the tape shows a beginning rivet hole spacing at (half the width of the stringer)or ½” and ending at 3 and 3/4s….for a rivet hole spacing of 3 to 3 and 1/4”  inches….this evidence seems to back that statement by former Lockheed employees.

Artifact 2-2-V-1 in the image below has been described as having a 4 to 4 and1/4 rivet spacing width. This is verified by the dimensions noted.   
http://tighar.org/wiki/File:2-2-V-1_interior_CAD.png

The stringers on the Model 10 taper (converge) slightly.  The stringers between Station 269 5/8 and Station 293 5/8 are farther apart toward the nose than they are toward the tail.  So a statement by a former Lockheed employee that "the Earhart Electra had 3” rivet spacing" (presumably he meant stringer spacing) is a meaningless generalization. 

The rivet lines on the artifact also taper. Exactly how the taper of the implied stringers on the artifact compares to the taper on the Model 10 has not been reliably established due to the distorted dimensions of the artifact.  We're working on that. Comparison of the artifact to an existing Lockheed 10 by the former Lockheed employee you refer to was done from a Mylar template of the artifact we provided to Elgen Long in 1992.  We have only recently come to realize that the distorted shape of the artifact distorts any template made from it.  In short, Long's analysis of what he called "the Nikumaroro Fragment" was invalid.  We know the rivet pattern is close but we don't know how close.

As stated, it does not appear that there was damage to the stringers in this area, and it is assumed they were left as per original.

Any major repositioning of stringers would require special engineering drawings mentioned in the Repair Orders and approved by the Bureau of Air Commerce. Such drawings were mentioned in the Repair Orders for strengthening splices on the nacelle ribs (where the landing gear had failed) and the subject special engineering drawings are part of the repair record.  The Repair Orders call for replacement of the skin of which 2-2-V-1 seems to be a part but no drawings are mentioned, so we must presume that the stringers didn't move much, if at all.

That  said, wouldn’t we expect the replacement panel  here, to bear a 3 inch rivet spacing?

No, we would expect the stringer spacing on the repair to have a similar taper as the original construction.  If the artifact is part of that repair we would expect the implied stringers to have the same spacing and taper, allowing for the distortion in the artifact.


And correct me if I am wrong, but when I look at this artifact installed here on the starboard side , it seems the artifacts rivet spacing narrows at the wrong end ( if the panel were installed in that position), and if I am looking correctly at the image in its suggested position ,it seems that  the two exterior rivet lines close at the end designated as the nose end…the innermost line stays pretty consistent , as would be expected as it is almost center belly.

Here again, oblique photographs and graphics derived from tracings of the artifact are deceiving.  The measurements in the illustration at http://tighar.org/wiki/File:2-2-V-1_interior_CAD.png were done from a tracing and they don't match measurements I just made on the actual artifact.  These errors have haunted our evaluation of this artifact for years and we're just now sorting them out.

In the direct overhead photo attached you can see that the lines of rivets taper slightly from bottom to top just as they should if the bottom edge is toward the nose and the right edge is along the keel.   As you say, not much taper near the keel, more taper further out.

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Tim Mellon

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Re: The Question of 2-2-V-1
« Reply #148 on: February 16, 2014, 10:39:26 AM »

Marty, I think you are completely misinterpreting what that article is saying.

"... but as soon as the volcano died, it started sinking under its own weight, a phenomenon called subsidence which, in this area, proceeds at a rate of 1 cm per hundred years."



I calculate that would be 7.6 millimeters since Earhart arrived at Niku.

And it would take that coral 3,000,000 years at that rate to reach 985 feet (300 meters).

Tim
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« Last Edit: February 16, 2014, 10:41:22 AM by Tim Mellon »
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Chris Johnson

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Re: The Question of 2-2-V-1
« Reply #149 on: February 16, 2014, 10:52:16 AM »

There is cold water coral that has been found growing at 3000m.
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