Sky & Telescope - August 2020 - 69

The Icebox
A little more on the boxy side, we ﬁnd
the late North Carolina amateur Bill
Madden's "Icebox Observatory." It
certainly does look like an icebox you'd
ﬁnd in front of a grocery store, and
it serves much the same function: It

protects what's inside from the elements and lets you get at it easily when
you need to. The two roof panels hinge
upward to become light barriers and
windbreaks, and the front wall panels
swing outward to allow access.
Easy to build and comfortable to
use, this design is a quick and effective
observatory project.
W Bill Madden's Icebox Observatory is simple
and functional. The structure is made of 2 ×
4s and plywood, and the top is covered with
rolled roofing with a generous overhang to
keep the rain out.
X The roof splits in two and hinges upward and
outward to become light- and wind barriers,
and the front panels swing outward to allow
easy access. Narrow shelving on the walls
holds charts, eyepieces, and other equipment.

A-Frame

siding. The building halves rest on inline castors, three under each wall, that
roll on 6-by-6-inch posts laid sideways
and are covered with 1/8-inch aluminum
plate. Ratchet straps pull the building
closed to form a tight seal, and hooks
and eyebolts hold it to the ﬂoor when
closed. A small door provides access
when the observatory is shut.
One feature all these observatories have in common is a solid resting
place for the telescope itself. You don't
want to set your telescope on the same
wooden ﬂoor you're walking on, because
any movement on the ﬂoor is trans-

ferred to the telescope and magniﬁed in
the eyepiece. Dan, Bill, and Mark all cut
out sections of the ﬂoor and set their
scopes on solid concrete foundations.
Mike made a solid concrete ﬂoor and
concrete pedestal for his mount.
T Left: Mark Bratton's A-frame observatory is
a variation on the common roll-off-roof design,
with a twist: His observatory is all roof! Right:
The A-frame halves roll sideways on in-line
castors riding on aluminum-covered 6-by-6inch rails set on a firm foundation. The scope
rests on a separate pedestal that's isolated
from vibration of the wood floor (which is
decidedly warmer underfoot than an entirely
concrete floor would be).

ICEBOX: BILL M A DDEN (2); A-FR A ME: M A RK BR AT TON (2)

Saskatchewan, Canada deep-sky
observer Mark Bratton had a little more
room in his yard, so he decided to go
with a roll-off-roof observatory, but his
observatory is an A-frame, which is all
roof! So he split the building in half and
rolls each half away to open up a generous portion of sky for observing.
The design is based on one by Greg
Mort that was featured in the March
1990 issue of S&T, p. 329, but Mark
made a few improvements. Each half of
the observatory uses 2-by-4s in a simple
frame construction, overlaid with
¾-inch plywood panels for the roof and
½-inch panels for the walls. Rooﬁng
underlay topped by asphalt shingles
completed the 60° pitched roof, while
the walls are ﬁnished with white vinyl

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