[time-nuts] Re: in-ground clock room

[Dana Whitlow]

One might also consider mounting smaller items inside the cylinders of the
engine block,
to get the most out of its thermal mass.

Dana


On Thu, Sep 9, 2021 at 11:03 AM Joseph Gwinn <joegwinn at comcast.net> wrote:

> On Thu, 09 Sep 2021 03:30:35 -0400, time-nuts-request at lists.febo.com
> wrote:
> Re: time-nuts Digest, Vol 209, Issue 6
>
>
> > ------------------------------
> > > Date: Wed, 8 Sep 2021 18:54:03 -0700
> > From: Tom Van Baak <tvb at LeapSecond.com>
> > Subject: [time-nuts] in-ground clock room
> > To: Discussion of precise time and frequency measurement
> >       <time-nuts at lists.febo.com>
> > Message-ID: <4037f6cb-ade3-8c01-8c36-7edf193274d6 at LeapSecond.com>
> > Content-Type: text/plain; charset=utf-8; format=flowed
> >
> > I am considering a below ground "clock room" away from the house. This
> > will be for some low-drift quartz oscillators and also a couple of
> > precision pendulum clocks. The goal is long-term, unattended, and very
> > undisturbed operation.
> >
> > For scale, assume the room is 1 meter × 1 meter × 2 meters deep. So
> > that's vastly smaller than digging a basement, but much larger than
> > drilling a 8 inch round pipe. Digging down gives some natural isolation
> > and temperature regulation. A couple tons of concrete gives high
> > stability vertical walls for the pendulum clocks.
> >
> > If any of you have personal or professional experience with the design
> > or construction of this sort of thing, especially experience with
> > precast (utility) vaults or poured concrete, please let me know.
> >
> > In case this gets too off-topic for time-nuts, off-list email to me is
> > fine (tvb at leapsecond.com).
>
> As others have said, it may not be economically practical to build an
> underground clock room.
>
> Assuming that you have a basement of other suitable room in your
> house, I'd suggest an insulated box or room containing a big lump of
> iron riding on an inner-tube suspension of some kind.   The big lump
> of iron can be a 500-pound truck engine head or block from a
> junkyard, steam cleaned (to remove oil) and painted (to keep the rust
> under control).  Drill and tap holes as needed for mounting.
>
> This box/room plus block can be set up as a temperature-controlled
> oven with a few extra components, including a PID controller.
>
> Bolt a thick plywood floor to the top of the iron hunk, and attach
> the clocks to this floor.
>
> Joe Gwinn
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