Well, it took some coordinating, but the
skeleton of the building
was finally erected with 3 days of work ending on July 12th.
The builder, the welder, the delivery truck, the boom crane truck,
and I all had to be at the building site on the same day.
Then things started happening rather quickly.
We bolted the base plates to the observing-floor slab, stairwell top, and
rolloff footers, and then welded the steel columns to them. Then the boom
crane got involved, hoisting the horizonal members to the top of the columns
for welding. We added the corner bracing and welded in the 14-gauge box
beams which will serve as purlins; these accept the screws that fasten the
siding to the walls. Finally, X bracing was installed between a number of
the columns to help keep the sidewalls from racking.
Left for the final day (after the photo was taken) was building of the base
frame of the roof and installation of the angle iron that will guide the
V-groove wheels on which the roof rolls.
To my immense relief, every bit of this "observatory frame on a truck" kit
fit perfectly. It was all rather like building a full-sized building with
parts from a Kenner Hydro-dynamic Building Set (I had one of those, back
in the day; it's still in a closet here somewhere). Each part was the right
size, dropped into place perfectly, and the whole thing welded together
with ease.
The one problem we had was with the braces in the corners at the top of the
wall. I had a local Tucson company cut 6-foot (2 meter) lengths of steel
box beam at 45-degree angles at each end to fit into the corners; it would
then be easy to simply weld them into place (or at least as easy as handling
115-pound (52 kg) pieces of steel at the top of a wall could be).
Unfortunately, they turned out to be rather less than certain what 45 degrees
was, and missed by quite a ways. I would have thought this was fairly
unambiguous, but incompetence abounds.
At any rate, this meant that placing the brace flush against
one wall beam made it wildly out of line with the adjacent wall beam; the
best compromise position left a gap of over an inch on each end.
We did the best we
could by adding some scrap pieces of steel; the result isn't pretty, but it is
functional.
We had to stop work several times during this phase; nobody wanted to be
anywhere near the boom crane or the steel when there was lightning in the
area (and boy, did we have some lighting!). We were suffering through
yet another month of record rainfall (the third such month of this project).
Some scrap residential siding was used to build a temporary roof over the
stairwell, else we'd have had an underground swimming pool instead of a
basement.
The end is in sight now, though!