Monday, September 7, 2015

What is the Zimmerman Object?


During the TIGHAR/Betchart Expeditions 2015 visit to Nikumaroro, TIGHAR member and Fiji Princess passenger Dr. Kimberly Zimmerman, along with several other project participants, came upon a metal box (Figure 1) in the feral coconut bush north of the “Gallagher Highway” (the pathway we cut on each visit from the landing to the lagoon beach at “Club Fred”). It was in a substantial cluster of historic material that included a sewing machine, an AEROVOX 630B R11 capacitor (collected and being studied by Joe Cerniglia), an enamel washpan, and several bottles.

Figure 1: Zimmerman Object in the wild

We had actually recorded the box before, at least as early as 1997 (Figure 2). On previous visits we had elected not to collect it, judging that it was almost certainly not from Amelia Earhart’s Electra 10E, but this time Dr. Zimmerman insisted that we do so, and was persuasive. So, calling it the “Zimmerman Object” (ZO) in her honor, we brought it back for identification and analysis.

Figure 2: 1997 Image of Zimmerman Object (upper center) in its artifact cluster

If the ZO turns out to be from the Electra, the joke will certainly be on us, since we have been walking past and scorning it for at least the last 18 years.

Physical Description

So what is it? Well, we don’t know, but here are its vital statistics as recorded immediately after its collection:

  • Subrectangular box, does not attract a magnet. Greenish patina suggests copper or a copper alloy.
  • Dimensions: Approximately 53 cm. (21”) by 45 cm. (17.7”) by 30.5 cm (12”).
  • Thickness of metal sheet: ca. 1.2 mm. (0.047”)
  • Four parts (one of them missing; see Figure 3)
Part A: A long rectangular sheet. Starting at point x on Figure 3, forms side A1, then was bent at a right angle at point y to create side A2. It was then bent at approximately 100 degree angle at point z to form side A3, which describes a gentle curve in the direction of point x  but is terminated at about 36 cm (14.17”). Part A forms the bulk of the artifact.

Parts (and Sides) B and C: Two side pieces, each with two straight edges and one curved edge.

Part (and Side) D (hypothetical, missing): Rectangular sheet about 31x45 cm  (12.2x17.7” ), closing the gap between the two ends of Part A.

Figure 3: Schematic of Zimmerman Object Sides

The parts were attached to one another by folding the edges of Parts (Sides) B and C over the bent-over edges of Part A, as diagrammed in Figure 4. Corners exhibit additional folded-over flanges (Figure 5). The connections between sides are not welded, but show spots of what may be solder.  A tiny fragment of fabric caught in the fold on side A2 (Figure 6) may indicate that there was some kind of gasket embedded in the folds, but if so it is apparent nowhere else on the artifact.

Figure 4: Schematics of connections between parts

Part B has become detached from Parts A and C, but was collected.

Figure 5: Corner of Side A2

Figure 6: Fabric in fold, Side A2
(Above 10 cm. mark)

  • Weight of Parts A & C: 3.81 kg (8.4 lb)
  • Weight of detached Part B: 1.042 kg  (2.3 lb)
Both ends of Part A exhibit folds similar to those connecting Part A with Parts B and C, so it appears that Part D was attached similarly, as diagrammed in Figure 4. Both have been pried open, presumably to remove Part D.

There is no evidence I can see that Part D was hinged on or latched to Part A. It appears to have been permanently attached.

Several of the edges exhibit cuts and tears.

Side A2, whose edge fold contains the tiny fragment of fabric, exhibits a reddish stain on both sides (Figure 7).

Figure 7: Side A2

The “Nipple”

Part C exhibits a small nipple on its interior surface, and a matching scar on its exterior. It appears that the nipple represents solder applied from the outside to fill a small hole, with its exterior surface then filed(?) flat, then covered with a rectangular object now missing (Figures 8, 9, 10).  The hole through which the solder extrudes (into the interior) is about  9.44 mm. in diameter, with ragged edges, distorted by being pushed in somewhat from the outside. The nipple of solder has a sort of “core” that might be small wire or plug, 3.5 mm. in diameter.

Part B, which otherwise matches Part C in every particular, does not exhibit a matching nipple.

Figure 8: Exterior overview Part (Side) C

Figure 9: Interior detail, Part (Side) C nipple

Figure 10: Exterior detail, Part (Side) C scar

Bob Draper, who with others identified the ZO’s metal as copper, pointed out that a common way to vacuum seal cans in the late 19th century was to draw air out through a tiny hole in the base which was then quickly filled with solder, creating marks very much like those on the ZO. This may or may not mean that the ZO was vacuum sealed, but it at least suggests that it had a small hole in the middle of Side C, which someone filled with solder and covered.

I can see no other distinguishing marks or attachments[1] – specifically:

  • No part numbers or other identifiers;
  • No brackets to attach the ZO to something else; and
  • No input or outlet pipes, valves, wires, cables, etc., but these may have existed in Part D.
Volume and Density Calculations

Engineer Tom Roberts, working from weights and measurements I provided, has computed the following descriptive variables for the ZO:

  • Approximate volume of metal in Part B (based on 1.2 mm thickness): 10.9 cubic inches
  • Approximate density of the material: 0.21 pounds per cubic inch
  • Approximate volume of the entire container if complete and closed: 3452 cubic inches, 0.057 cubic meters, 2.00 cubic feet or 14.9 gallons; with adjustments taking into account crumpling and bending of the material, Tom has opined that a capacity closer to 14.5 gallons might be more accurate.
Material Composition

At my request, Sturbridge Metallurgical Services (SMS) of Sturbridge, Massachusetts tested Part B to determine its metallurgical character. I can't master getting SMS’s report loaded here, but can supply it upon request. In brief, SMS determined that the Zimmerman Object is made of brass.

So What Is It?

In pondering the matter and in discussions with colleagues, several possibilities have come to mind:

1. Something brought to the island for use by the colonists, or fabricated there by the talented Public Works Officer Jack Kimo Petro or someone else. But brought or fabricated for what purpose? Presumably to contain something, but what? Why the curved side? And why is there no opening, fill port, or outlet – unless, of course, there was such a thing in Part D? Or perhaps there WAS no Part D, but why were the bent-over edges of Part A bordering the Part D gap pried open if there was no attached Part D to remove?

2. Something salvaged from the Norwich City wreck. This seems most likely, particularly since brass construction is relatively common in ships of the period, though it raises the same questions as above.

3. Something salvaged from the Loran Station[2]. This possibility raises the same questions as above, plus at least one other: if it was some item of military technology, why are there no identifying marks? No inscribed serial number, no stenciled label, nothing.

4. Joe Cerniglia, looking at the curved side of the object, suggested that it might have been designed to sit on a shelf in a Quonset Hut, several of which were built at the Loran Station. This is an attractive proposition, but if it is correct, it would place Part D, or the Part D opening, up against the side/roof of the hut, completely frustrating any access to the object’s interior.

5. Something from an airplane. The ZO’s shape tempts one to imagine it as a rigid removable fuel or oil tank (See designed to ride inside a compatibly shaped compartment (e.g. locations 75 or 72 in an aircraft similar to the one shownh in Figure 11).


Figure 11: Internal Structure of a Lockheed Electra 12

However, the ZO seems heavy for aircraft use; and if it was an aircraft fuel tank, the aircraft involved was almost certainly not Earhart's Lockheed Electra 10E. We have no record of a ca. 14.5 gallon fuel or oil tank in the Electra (Two 16-gallon wing tanks are reported), and no record of brass tanks or similar structures anywhere in the Electra’s construction.

6. Flotsam: something washed ashore from elsewhere, perhaps a passing ship, which opens a world of possibilities.

At this point – particularly as a non-airplane guy – I can only speculate; I tend to lean toward options 2 and 6 above. The ideas and criticisms of my colleagues (and anyone else) will be gratefully received.

Tom King

[1] A circular pattern that has appeared on Part B since it was brought to the U.S. is my fault. Apparently while the part was lying on a table I let something be set on top of it that dissolved the patina in a mirror-image pattern of whatever was on the bottom of the “something” thus set. The fact that the pattern includes the reversed letters “A” and “E” is understood to be fortuitous.
[2] Greg George has suggested the possibility that the ZO is a Faraday Cage, used to isolate a critical radio component from electrical or radio interference.