[Atmob-club] observatory design question

[Small, John]

I am in agreement with Peter KISS and stay with the rolloff.  TO make
one small change to the building process of a new school (or any public
building) will cost far more than the roll off in the field. The
building committee, architect and contractor's will need change orders,
and they will charge through the nose for them.  You would need fences
and a walkable surface on the roof if the public comes up, snow removal,
access and ADA Acccessable Acess. Harvard is a private institution so
they can sneek around the ADA access

The fact that it may not cost much in materials is mooted by the
political process that you will need to go through, think of all those
countless nights at meetings that you could be observing instead.   

Harvard Public affairs has issues too with the roof scope.  Many nights
we have had to close observing due to snow removal problems and ice 

Just my 2 cents worth
John Small

-----Original Message-----
From: pbealo at comcast.net [mailto:pbealo at comcast.net] 
Sent: Tuesday, January 15, 2008 12:01 PM
To: George Roberts; atmob-club at atmob.org
Subject: Re: [Atmob-club] observatory design question


George,

Interesting questions. I can only address a couple - and those mainly
with other questions (how socratic!):

1) The only stable building-mounted scopes I have ever seen were in
Munich at the Bavarian Public Observatory (
http://www.lrz-muenchen.de/~t7121bl/astro/vsw_e.html ). Steve Beckwith
and I had the opportunity to visit one of their open houses about 8
years ago. Their observatories are built on top of an above-ground WWII
vintage air-raid shelter. The walls were easily 3 ft thick concrete and
god knows how thick the ceilings were. BTW - this is the only  astro soc
"clubhouse" I ever visited that had a permanent bar and beer taps - just
a suggestion for the clubhouse committee  :>)   :>)
 Unless you're built on a similar structure, I'd say do not build an
observatory on a roof without an isolated pier to ground. You will not
know how bad it is until the money's spent and its built.

B) whether or not YOU want to have people on a school roof, what will
the school administration or school district say?!?! Will they be
willing to make a ruling today that binds them not to change it
tomorrow?? They are VERY risk-averse these days. For instance, according
to a friend living in Haverhill MA at the time, during the 1994 (I
believe) annular solar eclipse, their school district REQUIRED all
classrooms in the district to close their blinds. 

KISS: roll off roof at ground level. 

Peter



 -------------- Original message ----------------------
From: "George Roberts" <gr at gr5.org>
>      I'm still trying to get a small observatory built for the local 
> high school
> - hopefully a rolloff roof design in a field.  However, the whole high
school 
> will be rebuilt in about 3 years and this would be an opportunity to
put an 
> observatory on the roof.  There's a much better view from there.
Access would 
> be easier to control, and getting access to electricity, internet
would be 
> easier.  However there would be other issues.
> 
> One of the goals would be to be able to have occasional star parties 
> at night -
> invite the whole town or invite a class of students.  So we would need
to be 
> able to host up to 25 or hopefully even 40 people (limiting to 40
should be 
> fine).  So we would need deck space for "open observing".  So I would
still 
> favor a roll-off roof design even on an existing 3rd story roof
(strange).
> 
> I'm sure you have comments about this and please do, but my main 
> question is -
> in a normal modernly constructed steel building - how stable will the
roof be if 
> we mount the telescope right on the roof with no separate pier going
down 
> through all the floors into the bedrock (like they do at the clay 
> center/southfield/dexter school)?  With 25 people horseing around and
walking 
> around will that make the view of the moon vibrate annoyingly?  Or are
modern 
> steel (and concrete?) buildings so heavy and strong and stiff that it
will only 
> be a minor problem.  And how about when there are only 3 people
sitting down 
> calmly observing (which should be much more often)?  At night when the
school is 
> relatively empty and quiet?  Also what about when it is more crowded I
envision 
> a second or even third telescope setup on tripod on the roof?  I
imagine an 
> isolated rectangle of decking so that the tripod isn't resting on the
same piece 
> of wood as the people.  Or maybe it will be tar/gravel style roof with
no 
> decking.  Has anyone actually tried this?  
> 
> I know Harvard has that telescope on the roof and lots of people can 
> mill around
> outside the dome on the roof and look at the stars.  Do they ever
setup a second 
> telescope on a tripod out on the roof?  Does the view jiggle at all?
> 
> - George Roberts
>