to warm up. We completed all the work in
one day; the data center was brought back
up, and the instruments recovered. Net re-
sult: we reduced both the number of poten-
tial points of failure and the overall cost of
maintenance.
Other issues addressed in this shutdown
were the installation of improved encoder
mounts on the elevation axis, checks on
valves within the hydrostatic bearing sys-
tem, and leak checking on the Cassegrain
wrap Helium lines (one leak was found, and
we swapped that line to a backup).
On Friday August 31st, all systems were
handed back for observing; although bad
weather wiped out the first night while the
team was having a shutdown party. All sys-
tems were found in perfect working order,
and all the instruments checked out (includ-
ing GMOS after the bubble fix); the telescope
is now ready for another year of operation.
Every year, these shutdowns become more
efficient and streamlined. Careful planning
and attention to procedures and risk assess-
ments are paying off in making this more
and more a routine operation. A big thanks
to all involved in making this a success!
Gemini North Shutdown
Underway
Gemini North commenced its annual shut-
down on Monday, September 17th. Work
is progressing on several systems, includ-
ing A&G issue follow-up and maintenance,
Gemini Near-InfraRed Spectrometer cold-
head refurbishment and other maintenance,
GMOS VME hardware work, Near-InfraRed
Imager and spectrometer Detector Control-
ler troubleshooting, and Primary Mirror Con-
trol System maintenance. Additional work
planned includes enclosure bogie work and
enclosure bottom shutter work, which will
commence later in the shutdown.
Big Island Mechanical, the contractor install-
ing the Gemini North energy savings hard-
ware, worked together with Gemini day crew
to move the new Chiller 2 modules into the
Exhaust Tunnel and onto the vibration isola-
tion frame. Gemini is also temporarily shut-
ting down the Chiller 1 cooling water circuit
during the shutdown so that Big Island Me-
chanical can cut into the existing piping to
install new hardware.
Figure 10.
Performing
maintenance on
the Science Fold
mechanisms in one
slice of the A&G unit.
Credit: Joe D‘Amato
21
GeminiFocus
October 2018