TABLE OF CONTENTS
CFHT Observatory Facilities
These pages show the floor plans of each level in the dome. (under construction)
Channel 03: TV guiding camera (Cass and Coude)
Channel 06: Dome slit low light camera
Channel 07: West view of inside dome
Channel 08: Main entrance door
Channel 09: East view of inside dome
Channel 10: South view of telescope
Visitors are reminded that, in keeping with staff safety requirements, hard hats should be worn at all times when working in the dome area and main hatch area.
The temperature of the
dome area is controlled via a series of sensors distributed throughout
the dome and coupled to the
building glycol system. Cooling coils are
imbedded
in the concrete floor. Ventilation of the dome is controlled primarily
by
the motorized louvers at the top and bottom of the dome structure.
These
vents are normally left open to allow air to flow
between the skins of
the dome and closed when weather conditions require sealing off the
dome.
Controls for these louvers
are located on the mezzanine catwalk, inside
the dome.
In addition to the
dome skin
louvers, there are two fan units which can be controlled with a timer
or
switched on and off manually.
These units are also fitted with glycol
cooling
coils and capable of delivering chilled air to the dome area. The units
are located
on the N.E. portion of the dome, (directly over the freight
elevator) and also on the S.E. portion of the dome, (directly over the
visitors gallery).
The dome shutter is an
"up and over" type shutter, consisting of 12 hinged sections and driven
by eight motors on a rack and
pinion drive system.
The control of the shutter can only be done from the dome catwalk.
The windscreen is a
cable
driven device consisting of a series of steel partitions which store
themselves
in concertina fashion
at the base of the closed shutter. It is a
gravity-activated
lowering device and the sections tend to hang up in high wind
conditions.
Two slack cables have been recently fitted which prevent the down
motion
of the windscreen in that case. When it happens, the
dome has to be
rotated
to take the windscreen away from the wind and the cable driven up
before
attempting to cover the
windscreen. Like the shutter, the windscreen is
controlled from the dome catwalk.
Power dissipation in the dome is generally kept low. In particular, the sodium vapor flood lamps on the 5th floor are turned off
Observers bringing visiting equipment can help reduce power dissipation near the telescope by using the AC/DC power sources
Waimea Base Facilities
Version 1.0 January, 2003