Campbell: The first thing we at LASL did in a hole was called Pasal-A. It was 500 feet deep, in a cased hole. We put the bomb at the bottom of it, and we didn't stem it. So, we fired it. Biggest damn Roman candle you ever saw! It was beautiful. Big blue glow in the sky...
Bill Ogle was out there, in that timing station. When he saw that thing come out of the ground he knew he couldn't come south the way he came or he'd get into trouble... He was really excited about how they were going to get back... They were damn lucky they didn't go right through that cloud.
Carothers: Why didn't you stem it?
Campbell: Didn't need to. We did have a lid on that hole. Nobody's seen it since. We never did find that. On that lid was one of Johnny Malik's detectors, and we wanted a line of sight to see if we could measure some reactions. There was a kind of plug in the hole. It was a couple of hundred feet off the bottom, as I remember. All it was, was a concrete cylinder with a hole through the center of it, so the detector could look through it. And it had an annulus, so it wouldn't bind anywhere going down. It was suspended from the harness that was holding the bomb. It was a collimator, not a plug that was supposed to stem the hole. We never found that collimator either, and it was about five feet thick.
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But anyhow, bad as it was, spectacular as it was, there was only a tenth of the radiation on the ground around there that there would have been if it had been done on the surface.
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Bob Brownlee: ... Pascal-B and Pascal-C had plugs, but Pascal-A did not, although it had a concrete collimator in it for the detector on the surface. The guys had been working trying to get it ready, but there had been a number of troubles. They finally got it down the hole, by my recollection, about ten o'clock or so at night. There wasn't much time to go back to Mercury, go to bed, and get up the next morning to shoot it, so somebody said, "Why don't we just shoot it now, and then go in?" And it was the world's finest Roman candle, because at night it was all visible. Blue fire shot hundreds of feet in the air. Everybody was down in the area, and they all jumped in their cars and drove like crazy, not even counting who was there and who came out of the area.
[–] Alias_Unknown 0 points 2 points 2 points (+2|-0) ago
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[Caging the Dragon, pp. 20-22].