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[Tim Gard]

Having considered this line from Betty's note book for some time, I think the statement is relevant to the state of charge of the battery.

Given that the transmitter consumed current at an higher rate than the generator could supply, it became incumbent on the person transmitting to allow sufficient non-transmission time for the generator to recover the charge.

It sounds as though the panic precipitated one of the users to exceed the duty cycle and thereby hazard the next scheduled start especially if high water forced a shutdown before the battery's charge could be restored.

[Randy Conrad]

Tim...I was kinda wonderin exactly what you are referring too?  I guess I missed a posting of some sorts along the way. Anyway, while we're on the subject of watchin the battery..something came to my mind and want you forum members to help me out on this. I work in a battery manufacturing plant here in Kansas and know alot about the process and longevity of batteries. One thing I do know is that batteries need distilled water or acid when they become low or are overused or exposed to heat. When batteries are subjected to heat...they evenutally will lose a cell and the life of the battery if not cared for properly. I'm assuming that Amelia and Fred never took precautionary measures on the Electra like having an extra battery on board or maintenance kit to maintain the battery. Another thing that hasnt been mentioned is if this is the case and the only water resource they had to fill the batteries was salt water...then this could be very damaging. Plus, if you fill a warm battery up with cold water...its almost the same principle of filling up a radiator with cold water when its extremely boiling. Very damaging. But, corrosion is most likely the number reason why that battery failed. Like your car batteries...if your posts aren't well cleaned then you eventually lose power. I wonder if that was the case?

[Tim Gard]

Tim...I was kinda wonderin exactly what you are referring too?  I guess I missed a posting of some sorts along the way.

Anyway, while we're on the subject of watchin the battery..something came to my mind and want you forum members to help me out on this.

I haven't seen any evidence to suggest the batteries that started those big radials were defective or neglected. The Darwin photo shows the team were very aware of the needs of the Electra (Oleo Oil, engine oil etc).

Batteries will need distilled water added at short intervals if they are being overcharged or have shorted cells.

I have seen evidence that Amelia kept her transmissions brief because the generator on the starboard engine could not provide all the current the transmitter needed during transmission. That means any transmission drained the battery (or batteries depending on what Amelia had on line at that instant). Those brief transmissions are one reason why Itasca could not take a bearing on the Electra.

"Watch that battery" is consistent with the brief transmissions operating practice. It may also be that if the voltage fell below a particular level the transmission quality would be compromised, true for the July 8th 1937 transmissions consistent with operating with the generator offline.

Notice that the initial post of this thread is the anniversary of the transmission recorded in Betty's notebook.

[Ric Gillespie]

"Watch that battery" is consistent with the brief transmissions operating practice. It may also be that if the voltage fell below a particular level the transmission quality would be compromised, true for the July 8th 1937 transmissions consistent with operating with the generator offline.

It could be argued that there was nothing to watch, in that there was no meter that showed the state of charge of the batteries, but I would counter that they surely knew that if the charge in the batteries was allowed to become insufficient to start the engine - they were screwed. "Watch that battery!" could mean simply "I think you're transmitting too much!  Give the battery a chance recover."

[Kent Beuchert]

I started driving long before the advent  of sealed batteries, and I'm pretty sure there had been very little change in lead-acid battery technology from the time I started driving a car and Amelia's day. Adding water was a relatively rare thing to have to do, and although distilled water was preferred, almost no one bothered - tap water was virtually always used.  Obviously the limiting factor in Amelia's case was the lack of gasoline, or the inability to start or run the engine because of flooding. If they could physically run the engine and had gasoline, they could always recharge the battery, although without a battery gauge it would have  been rather a hit or miss operation. I would run the engine without the radio turned on, for a bit longer than the length  of time that I had used the radio. I would guess the critical factor to have probably been the gasoline supply.

[Jeff Victor Hayden]

This scientific paper sheds some light on how the battery charge state can be affected by various factors Tim. An interesting chapter covers 'Human, System, and Facility Safety – Threat of Fire and Explosion' Quote: "This outgassing scenario, while rare, can become an issue typically under unusual conditions, like abnormal over-voltage to the battery or abnormal high ambient heat conditions"

http://www.battcon.com/PapersFinal2008/ODonnellPaper2008PROOF_6.pdf

[Tim Gard]

If the battery charge state was of concern to the flyers, so that a restart could be performed after the tide receded, does that imply they were aware that fuel was not approaching exhaustion on July 5th 1937 (validated by subsequent transmissions)?

[Ric Gillespie]

If the battery charge state was of concern to the flyers, so that a restart could be performed after the tide receded, does that imply they were aware that fuel was not approaching exhaustion on July 5th 1937 (validated by subsequent transmissions)?

Hard to say.  The fuel gauges were not all that precise and they probably had no way to "stick" the tanks, so it would be hard for them to know when the rule was "approaching exhaustion' - however you define that. It could be that they figured they would just keep going until they ran out of gas.

[Monty Fowler]

My first thought on measuring the available fuel, after the gauges of course, would be a dipstick. A quick run through the Luke Field post-crash inventory shows nothing like that was carried then (doesn't mean it wasn't on the second flight), but  ... if you REALLY want to know if there's gas left, how hard would it be to whittle something from the ample flotsam on the beach or along the jungle's edge? It would not tell you how many gallons were left, but it could, with careful calibration, tell you how much of what was left you were burning up every time you fired up the engine to transmit.

LTM, who finds no paint as interesting as dry paint,
Monty Fowler, TIGHAR No. 2189 ECSP

[Ric Gillespie]

My first thought on measuring the available fuel, after the gauges of course, would be a dipstick.

Note that the fuselage tanks are filled through ports on the side of the fuselage, so the filler necks do not go straight down to the tanks.  How you gonna stick those tanks?

[Tim Gard]

What conclusions can we draw about the fuel remaining in the 100 octane tank?

Is it possible to conclude that the after takeoff level was still present after arrival and shutdown at Gardner?
Did Amelia switch to that tank as part of a potential go round procedure before arrival at Gardner?
Did the reduced gross weight mitigate the need for using 100 octane under takeoff power?

My take is that as much 100 octane as possible was preserved post Lae departure because it was scarce and it would be needed to depart Howland.

If Amelia's expectation at touchdown Gardner was that she would soon be refuelled and continue the flight from Gardner, then either way she would need to preserve the 100 octane.

[John Ousterhout]

Ric asks "How you gonna stick those tanks?"
I'll offer one possible answer: "you don't."  You pump all remaining fuel in those tanks up to the 118 gallon starboard "header tank" (my terminology) that has the sight-glass gage next to the cockpit door, which (I'm guessing) feeds the engines through the selector valve.  The cockpit had a manual fuel pump that could be selected to pump from any tank, as I recall.  I think it might be safe to assume it could pump to the tank that has the sight-glass.  Once the fuel level is below the bottom of the sight-glass, you've only got some fixed small quantity of fuel remaining, unless you discover a tank you hadn't previously tried pumping from, perhaps a forgotten tank partly full of 80 octane that you hadn't used since takeoff.
I don't recall confirming that the tank with the sight-glass was even a fuel tank, so this is supposition on my part.

[C.W. Herndon]

What conclusions can we draw about the fuel remaining in the 80 octane tank?

Is it possible to conclude that the after takeoff level was still present after arrival and shutdown at Gardiner?
Did Amelia switch to that tank as part of a potential go round procedure before arrival at Gardiner?
Did the reduced gross weight mitigate the need for using 80 octane under takeoff power?

My take is that as much 80 octane as possible was preserved post Lae departure because it was scarce and it would be needed to depart Howland.

If Amelia's expectation at touchdown Gardiner was that she would soon be refuelled and continue the flight from Gardiner, then either way she would need to preserve the 80 octane.

Tim, there was no 80 octane fuel on board the aircraft. Most of the fuel was 87 octane, later called 80/87 octane, with 100 octane reserved for takeoff. See here.

[C.W. Herndon]

If the battery charge state was of concern to the flyers, so that a restart could be performed after the tide receded, does that imply they were aware that fuel was not approaching exhaustion on July 5th 1937 (validated by subsequent transmissions)?

Tim, the Electra had two batteries on board, either of which could be connected or disconnected from the main buss for starting, radio use or charging. This one allow them to start the engine and use one battery for the radio while saving the other for starting the engine. Your guess is as good as anyone else's as to whether or not this is what they did.

[Tim Gard]

If the battery charge state was of concern to the flyers, so that a restart could be performed after the tide receded, does that imply they were aware that fuel was not approaching exhaustion on July 5th 1937 (validated by subsequent transmissions)?

Tim, the Electra had two batteries on board,

Yes. I'm aware of that and commented so ...

"That means any transmission drained the battery (or batteries depending on what Amelia had on line at that instant)."

They kept one fully charged battery isolated during the transmissions to mitigate the risk of losing them both as per Bob Brandenburg's text at your link.

That means the concern was directed towards the online battery.