[time-nuts] in-ground clock room

[Tom Van Baak]

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).

Thanks,
/tvb