Colossal
Heavy
Ultra-precise
Extremely Manoeuvrable
Super-rugged
Whenever an ALMA transporter moves a fragile, high-tech antenna
there is a lot at stake
This is demanding work for both man and machine
The two huge ALMA transporters, named Otto and Lore
crawl across the magnificent landscape of the Chilean Atacama desert
moving the sensitive antennas with the precision of the finest Swiss clockwork.
The capacity to relocate the antennas is a crucial aspect
of the operation of the powerful ALMA array.
This is the ESOcast!
Cutting-edge science and life behind the scenes of ESO,
the European Southern Observatory.
Exploring the ultimate frontier with our host Dr J, a.k.a. Dr Joe Liske.
ALMA — the Atacama Large Millimeter/submillimeter Array —
is the world's most powerful telescope for observing the cool Universe.
It consists of 66 high-precision antennas
that can be placed up to 16 kilometres apart.
Now, been able to move and reposition
each of these antennas individually
is precisely one of the reasons why ALMA
is such a powerful science machine.
But, moving the antennas requires a sophisticated
vehicle, that had to be custom-built for the job.
The ALMA transporter is an engineering wonder.
20 metres long, 10 metres wide and 6 metres high
it has 28 wheels fitted in pairs,
which can turn independently in any direction,
providing astonishing manoeuvrability.
This behemoth weighs 130 tonnes and is powered by
two 700-horsepower engines, giving a top speed of 20 km/h,
or 12km/h when carrying an antenna.
The driver’s cabin is set low down to ensure that the driver has a perfect view.
The transporter can also be controlled remotely,
allowing the operator to stand outside the vehicle and watch the machinery
during critical manoeuvres.
The sole purpose of the ALMA transporters is to move the antennas
around and to place them with millimetre accuracy.
That is not bad considering that each one of these antennas
weights in at more than 100 tonnes.
An antenna trip can range anywhere from a few hundred metres,
from one antenna pad to the next,
to some 28 kilometres from the base camp up to
the Chajnantor Plateau at 5000 metres above sea level.
The powerful engines of Otto are fired up.
Whenever an antenna move is scheduled,
the utmost attention of the transporter team is required.
Picking up a colossal ALMA dish will never become a matter of routine,
as the slightest mistake could result in a fatal accident.
The U-shaped frame of the transporter spreads the load evenly.
Carefully, the movers bring the transporter to an optimal position and
prepare the antenna for the trip.
Two angled rails secure the antenna as it is lifted on the transporters back.
The ALMA transporter keeps the antenna ,earthquake-safe,
in an ultra-rigid grip.
The antenna is repositioned with incredible precision on its new location.
But transporting an antenna from the base camp up to the
Chajnantor Plateau is an entirely different sort of challenge.
It’s a 28-kilometre climb up the mountain
with an altitude difference of some 2100-metres.
The long drive up the winding road is a test of both driver and engine,
and tension in the team is high.
At a maximum speed of 12 km/h the transporter creeps
along the custom-made road.
It is equipped with a unique suspension system that copes
with the washboard pattern of the road,
keeping the fragile load safe at all times.
This high-altitude driving is not a leisure trip: as the air thins,
the operators struggle to breathe and need to use supplementary oxygen.
Likewise, the power generated by the vehicle’s engines drops dramatically.
Finally, the plateau is reached and the antenna is lowered
with great precision onto its foundation pad
to increase the observational power of ALMA.
At first, these transporters may seem to be
just bulky monster trucks, bulging with power.
But of course, they are much more:
their ability to handle the fragile ALMA dishes
with such incredible care and precision makes them a simply
indispensable tool for ALMA.
And what’s more, they do it in harsh environmental conditions
and with unfailing reliability.
And so, this giants aren’t just trucks,
in a way they are actually part of the telescope.
This is Dr J signing off for the ESOcast.
Join me again next time for another cosmic adventure.
ESOcast is produced by ESO, the European Southern Observatory
ESO, the European Southern Observatory, is the pre-eminent
intergovernmental science science and technology organisation in astronomy
designing, constructing and operating the world’s most advanced ground-based telescopes.
The Atacama Large Millimeter/Submillimeter Array, an international astronomy facility,
is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile.
Transcription by ESO; translation by —