Re: Trinity Timing - How far we've come
For those of you who have just watched Oppenheimer, here is a classic
posting from 2008 that deserves fresh exposure [1]:
From: "Neon John" jgd@johngsbbq.com
To: time-nuts
Sent: Wednesday, March 12, 2008 5:27 AM
Subject: [time-nuts] Trinity Timing - How far we've come
In this paper
http://www.sciencemadness.org/lanl1_a/lib-www/la-pubs/00350316.pdf
you can read the detailed description (including schematics) of the
high accuracy
timing system built to control the Manhattan Project's Trinity test -
the first
nuclear device explosion.
This is an absolutely fascinating read. It is stunning what they did
with the
materials at hand and especially in the short time frame between when
the Gadget was
fairly certain to work and the test explosion.
The site time reference standard was, for example, a 1khz tuning
fork! Yet they
managed to time certain critical events to better than 0.1
microsecond and do so
despite having to drive miles of transmission line. Remarkable.
...
The 35 page now-unclassified PDF that John points to is still accessible
at that URL. It's a must-read for time nuts, especially if you're old
enough to have worked with vacuum tubes, or know about fast thyratron
switches [2] like the 4C35, or are just curious how nanoseconds timing
was done 75 years ago.
In a similar era, the hp 212A used a pair of hydrogen thyratrons [3],
see schematics [4]. The RadLab pulse book [5] has more examples.
The paper was written by British physicist Ernest Titterton [3] [4] in
1946 about the 1945 Trinity test. It looks like he was the "time nut"
for the experiment. If that doesn't get your attention here are some
keywords: "pulse rising 300 volts in less than 0.1 microsecond", "1000
yds of RG9U coaxial cable", "sawtooth generators and discriminators",
"hp 200C", "1 kc tuning fork frequency standard", Lissajou, "4C35
thyratron", "counter chronograph", interpolation, "detonator line
driver", "output amph. 80-C to Raytheon Unit on top of Tower".
Aside from a thousand other details of the Manhattan project, precise
timing was a critical [sic] requirement.
/tvb
[1]
https://febo.com/pipermail/time-nuts_lists.febo.com/2008-March/012789.html
[2] https://en.wikipedia.org/wiki/Thyratron
[3] https://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1950-02.pdf
[4] http://hparchive.com/Manuals/HP-212A-Manual.pdf
[5] https://www.febo.com/pages/docs/RadLab/VOL_5_Pulse_Generators.pdf
[6] https://ahf.nuclearmuseum.org/ahf/profile/ernest-w-titterton/
The local link is not working for me, but the paper is here
http://lib-www.lanl.gov/cgi-bin/getfile?00350316.pdf
http://lib-www.lanl.gov/cgi-bin/getfile?00350316.pdf, linked from
http://library.sciencemadness.org/lanl1_a/lib-www/la-pubs/00350316.html
David N1HAC
Hi:
On the Tube Collectors mailing list there was a discussion about the Nixie countdown display used in Oppenheimer and how
they did not exist at the time of Trinity.
Is there a paper similar to the one on timing that has an illustration of the control panel and countdown timer?
--
Have Fun,
Brooke Clarke
https://www.PRC68.com
axioms:
- The extent to which you can fix or improve something will be limited by how well you understand how it works.
- Everybody, with no exceptions, holds false beliefs.
-------- Original Message --------
The local link is not working for me, but the paper is here http://lib-www.lanl.gov/cgi-bin/getfile?00350316.pdf
http://lib-www.lanl.gov/cgi-bin/getfile?00350316.pdf, linked from
http://library.sciencemadness.org/lanl1_a/lib-www/la-pubs/00350316.html
David N1HAC
time-nuts mailing list -- time-nuts@lists.febo.com
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Hi,
Consider that the concept of count-down time may not even have existed
but added in film for dramatical effect in the film.
Count-downs as far as I know was used in space-race, and become a strong
dramatic concept at that time with televised launches etc.
Rather, if the timing was off a little here or there as such is not the
important part, but all the recordings was triggered with delay circuits
etc. or coordinated start, all depeding on their characteristics, is
enough. The relative timing is all that matters.
For space there is increasing need to hit a "window of opportunity".
because orbital mechanics etc. Today this also considers other
satellites and trash for safety.
Cheers,
Magnus
On 2023-07-27 19:56, Brooke Clarke via time-nuts wrote:
Hi:
On the Tube Collectors mailing list there was a discussion about the
Nixie countdown display used in Oppenheimer and how they did not exist
at the time of Trinity.
Is there a paper similar to the one on timing that has an illustration
of the control panel and countdown timer?
Hello to the group.
It is fascinating reading. Interesting on the cables just a few lines in
the text. But much of the control was actual twisted pair telephone cable.
They needed to make I believe a 8 mile detour around the gadget. Then there
are explanations of the issues with those long cables and how they worked
around them. The firing cable was buried coax.
With respects to the countdown I wonder also. I firmly believe the
countdown came from the German V2 rocket program. So I have heard.
With respect to timing the supporting experiments and cameras would have
needed the accuracy. It looks like pictures taken were faster than 1 ms.
Thats a lot of film.
So I suspect at detonation or just a bit after the old tuning fork would
have had a big phase jump...
Thanks for a great read.
Regards
Paul
On Fri, Jul 28, 2023 at 12:00 AM Magnus Danielson via time-nuts <
time-nuts@lists.febo.com> wrote:
Hi,
Consider that the concept of count-down time may not even have existed
but added in film for dramatical effect in the film.
Count-downs as far as I know was used in space-race, and become a strong
dramatic concept at that time with televised launches etc.
Rather, if the timing was off a little here or there as such is not the
important part, but all the recordings was triggered with delay circuits
etc. or coordinated start, all depeding on their characteristics, is
enough. The relative timing is all that matters.
For space there is increasing need to hit a "window of opportunity".
because orbital mechanics etc. Today this also considers other
satellites and trash for safety.
Cheers,
Magnus
On 2023-07-27 19:56, Brooke Clarke via time-nuts wrote:
Hi:
On the Tube Collectors mailing list there was a discussion about the
Nixie countdown display used in Oppenheimer and how they did not exist
at the time of Trinity.
Is there a paper similar to the one on timing that has an illustration
of the control panel and countdown timer?
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
The book you /really/ want to read is "Atomic Hostages" by O'Keefe.
He worked for EG&G and comes very close to saying that he personally
triggered all but three of the atmospheric nuclear detonations USA
performed.
From my reading, they tried very hard to hit the precise time,
because not all instrumentation was triggered automatically, and
early on the countdown seems to have been broadcast for distant
film cameras.
--
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Possibly:
The Nuclear Hostages Hardcover January 1, 1983
by Bernard J. O'Keefe (Author)
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-----Original Message-----
From: Poul-Henning Kamp via time-nuts [mailto:time-nuts@lists.febo.com]
Sent: Friday, July 28, 2023 2:02 PM
To: Discussion of precise time and frequency measurement
Cc: Poul-Henning Kamp
Subject: [time-nuts] Re: Trinity Timing - How far we've come
The book you /really/ want to read is "Atomic Hostages" by O'Keefe.
He worked for EG&G and comes very close to saying that he personally
triggered all but three of the atmospheric nuclear detonations USA
performed.
From my reading, they tried very hard to hit the precise time,
because not all instrumentation was triggered automatically, and
early on the countdown seems to have been broadcast for distant
film cameras.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
time-nuts mailing list -- time-nuts@lists.febo.com
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Lester Veenstra writes:
Possibly:
The Nuclear Hostages Hardcover =96 January 1, 1983
by Bernard J. O'Keefe (Author)
Sorry, yes: "Nuclear Hostages"
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.