|
The Large Binocular Telescope (LBT)
located on
Arizona’s Mount Graham, USA has utilised
Rexroth aluminium profiling in its
construction |
Bosch Rexroth,
locally represented by Tectra Automation, has
supplied extruded aluminium profiling to be used
to rapidly erect structures and safety
constructions on the Large Binocular Telescope (LBT)
located on Mount Graham in Arizona, USA. The
fascinating LBT will allow scientists to peer
into the depths of the universe.
Structural engineering plays a vital supporting
role at the facility. As tall as an 11-storey
building, the LBT’s viewing power exceeds that
of the Hubble telescope by factor 10. The LBT is
also the only telescope in the world that uses
two mirrors, each 8,4 metres in diameter, on a
common platform. The mirrors are linked
optically, and attain a resolution corresponding
to that of a 22.5 metre mirror.
Located about 24 metres below the mirrors is the
PEPSI (Potsdam Echelle Polarimetric and
Spectroscopic Instrument), a high-resolution
spectrograph built by the Astrophysical
Institute of Potsdam (AIP) in Germany. The PEPSI
has to be fed continuously with the light
gathered. The light then passes through
high-sensitivity fibre optic waveguides, which
are bundled inside jackets to form the so-called
energy chain. One of the project’s major
challenges has been to stabilise the energy
chains, to enable each energy chain to move on
both the horizontal and vertical plane to follow
the mirrors’ motion without affecting the light
feed.
A further problem arose from installing the
PEPSI in a temperature and air pressure
controlled space, located at the lowest point in
the azimuth pit. This space is actually a large
concrete cylinder with a centre that corresponds
to the telescope’s vertical axis. The fibre
optics involved needed to be routed down through
a small opening to the spectrograph, as the
azimuth pit needs to be covered to prevent
accidents. The problem was solved by using
extruded aluminium from Bosch Rexroth in a lot
of the project applications.
Developing a modular framing system in which the
cable track holding the waveguide was mounted on
extruded aluminium beams; and using two energy
chains solved the energy chain problem. The
upper energy chain guides the fibre optics when
the telescope moves horizontally; and the lower
energy chain performs the same task when the LBT
moves vertically.
A major benefit of using Bosch Rexroth’s
profiling and its accompanying versatile
connectors is how quickly and efficiently
structures can be assembled. A decision by the
engineering team to lay one of the permanent
ladders above the azimuth pith meant that the
energy chain had to be reinstalled on the
opposite side. It took only three hours to
dismantle the framing, reconfigure and
reassemble it, and mount it again. |
