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Going like a bat!

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by Joe Brown

Scale: 1/48

1957 - The year that humans put objects into space. Everyone knows about Sputnik, which was launched on October 4, 1957. But, what about the event on August 27, 1957? A mine shaft hole cover plate that was four inches thick and four feet across. It weighed 1984 pounds (900 kilograms) and was launched with a plutonium fission bomb?

Yep. That is to say, up to a specific point, it is very real. Yes, it honestly happened. But, after a specific point during the event, it's all conjecture . . . for now.

Here is the history part:

  • Test Series: Operation Plumbob
  • Test name: Pascal-B
  • Time: 22:35:00.00 27 August 1957 (GMT)
  • Location: NTS, Area U3d
  • Test Height and Type: 500 feet underground, open shaft
  • Yield: Often listed as "slight," actual yield 300 tons
  • Device Description: 64.6 lb; 11.75 x 15 inches; plutonium pit; PBX 9401 and 9404 explosives

Dr. Robert R. Brownlee's own words from his website: “Incidentally, the Pascal B test, and those immediately following, had a 4-foot-diameter pipe. The cap welded to the top of Pascal B was four inches thick, so was of appreciable mass from a 'man-handling' point of view. For Pascal B, my calculations were designed to calculate the time and specifics of the shock wave as it reached the cap. I used yields both expected and exaggerated in my calculations, but significant ones.

When I described my results to Bill Ogle, the conversation went something like this:"

Ogle: “What time does the shock arrive at the top of the pipe?”
RRB: “Thirty one milliseconds.”
Ogle: “And what happens?”
RRB: “The shock reflects back down the hole, but the pressures and temperatures are such that the welded cap is bound to come off the hole.”
Ogle: “How fast does it go?”
RRB: “My calculations are irrelevant on this point. They are only valid in speaking of the shock reflection.”
Ogle: “How fast did it go?”
RRB: “Those numbers are meaningless. I have only a vacuum above the cap. No air, no gravity, no real material strengths in the iron cap. Effectively, the cap is just loose, traveling through meaningless space.”
Ogle: “And how fast is it going?” [This last question was more of a shout. Bill liked to have a direct answer to each one of his questions.]
RRB: “Six times the escape velocity from the earth.”

“Bill was quite delighted with the answer, for he had never before heard a velocity given in terms of the escape velocity from the earth! There was much laughter, and the legend was now born, for Bill loved to report to anybody who cared to listen about Brownlee's units of velocity. He says the cap would escape the earth. (But of course we did not believe that would ever happen.)

The next obvious decision was made. We'll put a high-speed movie camera looking at the cap, and see if we can measure the departure velocity.

In the event, the cap appeared above the hole in one frame only, so there was no direct velocity measurement. A lower limit could be calculated by considering the time between frames (and I don't remember what that was), but my summary of the situation was that when last seen, it was 'going like a bat!!'

As usual, the facts never can catch up with the legend, so I am occasionally credited with launching a 'man-hole cover' into space, and I am also vilified for being so stupid as not to understand masses and aerodynamics, etc., etc., and border on being a criminal for making such a claim.”

Now for the fiction . . .

Given the current contest on Starship Modeler, I personally think it's humorous to assume that the cover plate was not vaporized and to go ahead and plop it onto the lunar surface.

With the “estimated” six-times-escape-velocity speed (and the nonaerodynamic nature of the cover plate), I decided I could reasonably tweak the story of the cover plate to ensure that it made it to the moon. But then the question becomes, where?

August 25 1957, was a new moon, making August 27 a waxing crescent moon. Is there a (relatively) simple template formula to calculate this sort of a flight path? Well, when in doubt ask the nearest expert, so I did!

Winchell Chung (Nyrath) kindly offered me some thoughts when I requested his assistance. “Now, if it has six-times-earth-escape velocity, it also has two-times-solar-escape velocity, so it has enough speed to go anywhere in the galaxy. It certainly has enough to go to the moon.

Now, the moon always keeps the same face to the earth (more or less), even if all of it is not always visible. So even if it is a waxing crescent, the entire near side of the moon is facing the earth.

Unfortunately, there is no simple way of calculating if the cover plate even hit the moon, much less where on the moon. Chances are it missed the moon, but if you want it to hit, you could pretty much pick any spot you wanted.”

So, it was now fairly reasonable for me to assume that the cover plate survived its blast off through the earth's atmosphere and made it to the moon. For a lunar surface, I used Wilco Model's excellent base for their kit of the Luna. This was primed and then painted Krylon Ultra Flat Black. This was allowed to dry and then coated with a thin layer of Bob Ross White Gesso. I rinsed the brush clean, and then I used the still very damp brush to go back over the entire surface of the base. This had the effect of thinning the white gesso, which gave it a dirty white, almost gentle gray look much like the lunar surface.

The actual steel cover plate was a bit harder. I really wanted to use the Wilco base, so, the model of the cover plate had to be small. I settled on metal “snap” grommets as a likely candidate. With the help of my needle-nosed pliers, I was able to successfully mangle a grommet into the proper shape. With the help of pinpoint drops (micro drops) of Tamiya Clear Red, Clear Green, and Clear Blue, I was able to simulate the colors that are often found on heated metals. And, a careful spritz of more Krylon Ultra Flat Black helped too!

So, to close, I need to point out that the cover plate has never been found and was most likely destroyed or went past the moon. But, nobody knows what really happened to it. So why couldn't it be on the moon?

Image: Side view

Image: From above

Image: Primer test

Image: "Test fit"

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This page was last updated 1 July 2009. © 2009 Starship Modeler