|
|
The roof originally was designed to roll on eleven 3-1/2 inch
low friction steels wheels set in 40 foot long "U" shaped
channel iron tracks on each side. The roof was calculated to
weigh 4000 lbs. It would seem obvious that anything weighing two
tons would take a lot of force to move it. Incredibly, no one
ever bothered to calculate how much force it would actually take
to move the roof. JEM has a 14 x 14 foot roll-off roof
observatory, The Sabino Canyon Observatory, and there is little
difficulty in manually moving its roof, causing us to assume we
could manually move the roof of the Grasslands Observatory.
Unfortunately, there was a very unpleasant surprise the first
time we tried to roll off the Grasslands Observatory's roof by
hand. It took all the strength of three people to even budge it
a few inches.
Don't make this mistake yourself! Calculate the weight of your
roof or dome and determine how much force it will take to move
it. Then design a good system of pulleys, winches, and motors to
properly move it. In all cases, even with very heavy roofs and
domes, be certain they are securely attached to the building
proper when the observatory is not in use; otherwise, the roof
may be completely blown off in a strong storm.
IV. EVERYDAY PROBLEMS
Checklists are considered mandatory by private and professional
pilots for good reason. You don't want to forget something
important when flying a plane. Checklists (Table II) can also be
very useful for the amateur astronomer. Over the years we have
left film, eyepieces, cameras, star charts, sandwiches, computer software, computer hardware, and
binoculars at home. Besides using checklist to avoid forgetting
something important, try to have all the items that you need at
the observatory. Sometimes, this is not possible with perishables, and it can be expensive to duplicate every
chart and eyepiece for home and the out of town observatory.
Nevertheless, you should not scrimp so much on equipment that
you have to transport everything back and forth.
TABLE II -- OBSERVER'S CHECKLIST
A. Observing Items
1. Camera(s), lenses, filters, adapters, shutter release.
2. FLASHLIGHTS-white & red; BATTERIES.
3. Computer items: software, hardware - spare CDs, USB flash drives, portable hard drives, flash cards...
4. Books: Atlases, charts, guide books, logs.
5. Binoculars, off axis guider, illuminated reticle.
6. Eyepieces
7. Table, lawn chairs
8. FUSES
9. Tape recorder
10. Tape: DUCT TAPE, Scotch tape, electrical tape.
11. Tarp, plastic ground cover.
12. Hair dryer.
B. Car Items
1. Blankets, flares, reflective triangle, matches, cigarette
lighter, whistle, small tarp, compass.
2. Tools: hammer, screw drivers, socket wrenches, an adjustable
wrench, pliers Allen wrenches, knives
3. BATTERY OPERATED TIRE PUMP. Unless the
tire is torn up or has blown out a side wall, it is possible to
inflate a tire even on a large truck and drive on the tire for
an hour or more. It is preferable to have a service station
mechanic change the tire then to do it yourself.
4. Spare parts: hoses, belts, battery, engine coolant.
5. CB radio or cellular telephone.
6. FUSES.
7. Friction Tape.
8. Rags, work gloves.
9. HEAVY DUTY - 6 or 8 GAUGE - JUMPER
CABLES 12 FEET LONG. Do not skimp on jumper cables and purchase
a cheap, lightweight set. They will not start a severely drained
battery, and they may overheat and catch on fire!
10. SHOVEL.
11. Tow Cable.
12. FIRST AID KIT: bandages, gauze wrap,
paper tape, gauze pads, aspirin, isopropyl alcohol, elastic
wrap, tourniquet.
13. HIDDEN SPARE CAR KEY; SPARE
OBSERVATORY KEY or LOCK COMBINATION.
C. Personal Items
1. WARM CLOTHING.
2. Drinking water.
3. Thermos for coffee, cocoa, tea, or hot water.
4. Ice chest for sodas and food; candy bars.
5. Personal medications.
6. If you frequently take nitroglycerin for angina or are an
insulin dependent diabetic, observing alone in a remote location
is probably not wise.
7. Portable radio or boom box.
8. Toilet paper and paper towels.
9. Insect spray and insect repellant.
10. Sleeping bag.
Before important tools,
eyepieces, charts, books, and a computer system for the
Grasslands Observatory were purchased and left there permanently, we had to
spend nearly an hour packing the car for a trip out to the
observatory. Make a list of critically important items (Table
III) and leave these in the observatory. One rarely has need for
a shovel or pickaxe on a daily basis, but when you need it, you
need it badly. It's no fun to find out that you could use a
shovel when its 3:00am, and you are sixty miles from home.
Experience will teach you what implements you should have. Buy
them and plan plenty of storage space so they will be out of the
way and not under foot.
By the way, what will you do if you have finished up a night's
observing at 4:00 AM and discover your car won't start? If you
are sixty miles from home in a remote desert location with no
phone, this is a serious problem. If you are going out to a
remote observatory alone or with others but taking only one
vehicle, use a reliable automobile. Weak batteries, flat tires,
and loss of engine coolant are the most frequent and amenable
causes of automobile breakdowns. Be prepared to deal with them.
Carry an assembly of spare parts and tools (Table II). Always,
always, always have flashlights. When you have spent a hundreds
if not thousands of dollars on your observatory, it foolish not
to invest an extra $200 for car tools and spare parts. Even if
you don't have the skill to fix a complex problem, someone else
might if you have the tools and parts for them to use.
TABLE III PERMANENT OBSERVATORY EQUIPMENT
1. FLASHLIGHTS; SPARE BATTERIES.
2. FIRST AID KIT (as above).
3. Fence post driver.
4. Tools (as above); tape (as above).
5. Pickaxe; shovel; axe.
6. Lamp(s); spare light bulbs.
7. Red cellophane.
8. Nonperishable food and drink; cups, glasses, plates,
utensils.
9. FIRE EXTINGUISHER.
10. CB radio or cellular telephone if there is no regular phone
service.
11. FUSES.
12. Toilet paper; paper toweling; tissue paper; soap.
13. Radio; cassette player; tapes, CD's.
14. Pens, pencils; writing pad.
15. Logbook; guest book.
16. Charts; atlases; computer software, spare disks.
17. Eyepieces.
18. Battery pack to operate telescope.
19. Spare car battery and/or battery charger.
20. HIDDEN SPARE KEY OR LOCK COMBINATION.
Be on friendly terms with your neighbors; they might let you use
their phone in the middle of the night or give you a ride to
town or call 911 for you in case of a serious accident. The
Grasslands Observatory property is bounded on the south and west
by a 60 acre farm inhabited by a family disenchanted with urban
life. Unfortunately, one of their first acts after setting up a
temporary home and fencing their property was to install an
obnoxious, unshielded dusk-to-dawn, mercury vapor "security"
light. Because it was a quarter of a mile away from the
observatory, it did not ruin dark skies. It was an irritating
annoyance and certainly intruded on the enjoyment of otherwise
untrammeled dark skies.
There are good light pollution ordinances in southern Arizona.
This light could have been cited by the county authorities and
taken down. This certainly would have taken some time and effort
on our part and would have generated much ill-will. Instead, we
tactfully explained the problem to the neighbors who initially
elected to paint the part of the light facing the direction of
the observatory. This considerably reduced the light emitted
toward the observatory, though it was not a perfect solution. In
the last couple of years, the light has not been used and is
never turned on. The neighbors have completed a permanent house,
and they are kind enough to watch over the observatory.
You can't buy enough land to prevent someone from moving in next
door and causing you some inconvenience. Head off problems
before they arise and work with your neighbors for the maximum
benefit of all. There is no way to completely prevent vandalism
but having watchful neighbors helps. Situate your observatory
out of view as much as possible, keep it locked when not in use,
fence your property, and have it watched by helpful neighbors.
Vandalism and theft are always potential problems, but it is
self-defeating to be so worried about them that you do not build
an observatory. Enjoy your hobby and get a good insurance
policy, which will not be cheap.
One of our best decisions was to carpet the entire observatory.
Carpeting adds an aesthetic quality and reduces leg fatigue from
long hours of standing up. Even on cold winter nights, carpeting
provides enough insulation for someone to lay down on the floor.
This is not possible with a concrete or wooden floor. We also
built a 2 foot wide bench along the north side of the building
which has worked well for sitting, reclining, sleeping, and
storing loose odds and ends.
There is no way to keep dust out of an observatory. Because
there is a moving roof, there is a ready access for the entrance
of dust and moisture. To keep this to a minimum, caulk and seal
obvious spots where wind, dust, and water can enter the
building, design your roof or dome opening as snug as possible,
and then keep all your books, eyepieces and other valuables
under cover when not in use. Be prepared to dust your desk and
other working surfaces every time you open up for a night's
observing. Dew is generally not much of a problem in Southern
Arizona, but there are occasional moist nights. These require
the use of a hair dryer to keep dew off optical surfaces.
Even in a dry climate such as Southern Arizona, moisture buildup
inside a sealed, unheated, non air-conditioned building, such as
the typical amateur observatory, is quite a problem. Metal
surfaces become corroded, and books become warped and damaged.
Cover or seal anything that may potentially be harmed by dust
and moisture.
You are not likely to plan an observing session during a
thunderstorm. However, you might be caught by one unexpectedly
or decide to observe just after a storm has passed through.
Sometimes, the clearest, steadiest skies follow a storm passage.
So does mud. Once it is tracked into the observatory, it is very
hard to remove. Plan for door mats, foot scrapers, and, if
possible, a sidewalk. Even better, try to design a system where
there are strategically placed paved walkways so you can enter
and leave your car without ever having to step through dirt and
mud. Make sure the walkway does not radiate heat in front of the
telescope.
An observatory is not immune to fires. The day we completed the
observatory, there was the largest grass fire in Southern
Arizona history. It consumed 9000 acres of grasslands and
unbeknownst to us at one point totally surrounded us. Luckily,
it stopped at our neighbor's western boundary and did not bother
either him or us.
Fires are rather good for grasslands but not for observatories.
Have one or more fire extinguishers and spare water available
for small fires. If caught early, a small fire can be contained.
You can't stop a large grass fire or forest fire, but you can
have a contingency plan in case of a large fire.
|
