telescopes on concrete roof

In article , Maurice Gavin
writes
We need some practical advise re mounting telescopes on a large flat
roof [immediately overlooking fields to the E/S/W] to minimises
potential vibration mainly from dozens of observers walking about.

We are aware of the potential thermal problems from the building
- a substantial 1930s three storey brick structure with protective
parapet and rc asphalted roof. There are no pumps/ machinery/ people
within the building and no option for independent piers down to ground
level. The asphalte membrane cannot be disturbed to mount the
telescopes direct onto the concrete structure below.

The scopes range from 10cm - 40cm aperture and weight is not a problem
for roof loading. Non-portable telescopes will be protected with
run-off sheds/ grp domes.

Any thoughts? Should the walk-about area be padded and with what?
Such mats must remain in place and be safe, self-draining and
rotproof. TIA.

Try alternate layers of 3 to 4mm gasket rubber and lead, 4 layers of
each, top off with a small paving slab , used a similar system on a mono
layer forming trough to good effect .... Jon V
--
Jonathan Vogel

JRS: In article , seen in
news:uk.sci.astronomy, Maurice Gavin posted at Tue,
1 Jul 2003 18:54:53 :-
We need some practical advise re mounting telescopes on a large flat
roof [immediately overlooking fields to the E/S/W] to minimises
potential vibration mainly from dozens of observers walking about.

...

Presumably you should protect the existing roofing from any routine
contact with observers' footwear; and, if it is like roofs I've seen,
/vice versa/.

Also you should spread the load for any equipment, perhaps by laying
paving stones under each leg.

Remember wind loading on anything permanently-placed.

If you can locate a generous supply of close-boarded pallets, you might
be able to floor the roof relatively rapidly.

Think also about site security.

--
© John Stockton, Surrey, UK. Turnpike v4.00 MIME. ©
Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
some Astro stuff via astro.htm, gravity0.htm; quotes.htm; pascal.htm; &c, &c.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.

In message , Maurice Gavin
writes
We need some practical advise re mounting telescopes on a large flat
roof [immediately overlooking fields to the E/S/W] to minimises
potential vibration mainly from dozens of observers walking about.

You could try nailing the observers down. Or at least discourage them
from walking around too much. Cork isn't too bad at absorbing vibration.

We are aware of the potential thermal problems from the building
- a substantial 1930s three storey brick structure with protective
parapet and rc asphalted roof. There are no pumps/ machinery/ people
within the building and no option for independent piers down to ground
level. The asphalte membrane cannot be disturbed to mount the
telescopes direct onto the concrete structure below.

Pity. The easiest way to do it is with isolated piers for the scopes.

You might get away with it though if the structure is heavy and rigid
enough. Try a site survey with an 8" SCT to see how bad the problem is
with a couple of guys jumping up and down on the roof.

You might get enough mileage by putting the scopes on a couple of sacks
of damp sand for isolation. (Or the bits sold for record turntables).
Put the scopes immediately above load bearing walls and they may be OK.

The scopes range from 10cm - 40cm aperture and weight is not a problem
for roof loading. Non-portable telescopes will be protected with
run-off sheds/ grp domes.

Any thoughts? Should the walk-about area be padded and with what?
Such mats must remain in place and be safe, self-draining and
rotproof. TIA.

Cork mats probably meet your requirements, but if the structure is big
and heavy enough the effects of a few people wandering around may not be
all that bad (unless they all decide to march in step - a la blade of
light).

--
Martin Brown

In message , Maurice Gavin
writes
We need some practical advise re mounting telescopes on a large flat
roof [immediately overlooking fields to the E/S/W] to minimises
potential vibration mainly from dozens of observers walking about.

You could try nailing the observers down. Or at least discourage them
from walking around too much. Cork isn't too bad at absorbing vibration.

We are aware of the potential thermal problems from the building
- a substantial 1930s three storey brick structure with protective
parapet and rc asphalted roof. There are no pumps/ machinery/ people
within the building and no option for independent piers down to ground
level. The asphalte membrane cannot be disturbed to mount the
telescopes direct onto the concrete structure below.

Pity. The easiest way to do it is with isolated piers for the scopes.

You might get away with it though if the structure is heavy and rigid
enough. Try a site survey with an 8" SCT to see how bad the problem is
with a couple of guys jumping up and down on the roof.

You might get enough mileage by putting the scopes on a couple of sacks
of damp sand for isolation. (Or the bits sold for record turntables).
Put the scopes immediately above load bearing walls and they may be OK.

The scopes range from 10cm - 40cm aperture and weight is not a problem
for roof loading. Non-portable telescopes will be protected with
run-off sheds/ grp domes.

Any thoughts? Should the walk-about area be padded and with what?
Such mats must remain in place and be safe, self-draining and
rotproof. TIA.

Cork mats probably meet your requirements, but if the structure is big
and heavy enough the effects of a few people wandering around may not be
all that bad (unless they all decide to march in step - a la blade of
light).

--
Martin Brown

"Chris.B" wrote in message
om...
(Maurice Gavin) wrote in message
...


Any thoughts? Should the walk-about area be padded and with what?
Such mats must remain in place and be safe, self-draining and
rotproof. TIA.

Astro-Turf comes to mind.

I agree entirely with this! You could try carpet underlay under the
astroturf too- if not too cheap a grade it should last. I've had a chunk of
30 odd year olde underlay bunged under an old fish tank for the last two
years outside and it is still AOK. That should keep even the biggest zeppos
from jolting the instruments!

Martin T

"Martin Taylor" wrote in message
...

"Chris.B" wrote in message
om...
(Maurice Gavin) wrote in message
...


Any thoughts? Should the walk-about area be padded and with what?
Such mats must remain in place and be safe, self-draining and
rotproof. TIA.

Astro-Turf comes to mind.

I agree entirely with this! You could try carpet underlay under the
astroturf too- if not too cheap a grade it should last. I've had a chunk of
30 odd year olde underlay bunged under an old fish tank for the last two
years outside and it is still AOK. That should keep even the biggest zeppos
from jolting the instruments!

Martin T

Its still not 2007 !!!

"Steven Pilbeam" wrote in message ...


Its still not 2007 !!!

I'm delighted to hear it! Thankyou for sharing this important news.

Chris.B

"Steven Pilbeam" wrote in message ...


Its still not 2007 !!!

I'm delighted to hear it! Thankyou for sharing this important news.

Chris.B

"Martin Taylor" wrote in message
...

"Chris.B" wrote in message
om...
(Maurice Gavin) wrote in message
...


Any thoughts? Should the walk-about area be padded and with what?
Such mats must remain in place and be safe, self-draining and
rotproof. TIA.

Astro-Turf comes to mind.

I agree entirely with this! You could try carpet underlay under the
astroturf too- if not too cheap a grade it should last. I've had a chunk of
30 odd year olde underlay bunged under an old fish tank for the last two
years outside and it is still AOK. That should keep even the biggest zeppos
from jolting the instruments!

Martin T

Its still not 2007 !!!

"Chris.B" wrote in message
om...
(Maurice Gavin) wrote in message
...


Any thoughts? Should the walk-about area be padded and with what?
Such mats must remain in place and be safe, self-draining and
rotproof. TIA.

Astro-Turf comes to mind.

I agree entirely with this! You could try carpet underlay under the
astroturf too- if not too cheap a grade it should last. I've had a chunk of
30 odd year olde underlay bunged under an old fish tank for the last two
years outside and it is still AOK. That should keep even the biggest zeppos
from jolting the instruments!

Martin T