
Accurate Schedules
March 28, 2009
Every day after lunch, the scientists meet to schedule science events
for the next few days. These meetings optimize use of the ship’s time
and help experiments stay on track. Underestimating on a two- or
three-day schedule means that small errors can snowball into a buildup
of late deployments. During the meetings, the principal investigators
must decide how much time each deployment will take.
To estimate how much time a deployment requires, the first consideration
the scientist must make is where to deploy—steaming 18.5 kilometers
takes about an hour. If a science event must happen 20 kilometers away
from the previous event, the principal investigator must include an hour
of transit time.
Once the ship arrives at the preferred location, equipment must be put
into the water. For some instruments, deployments are quick and
straightforward; the CTD is located in the Baltic room, which is
designed specifically for CTD deployments. On the other hand, deploying
ROV IceCUBE requires consideration of many variables; positioning the
ship next to the iceberg, currents, water conditions, and dive
objectives change with each deployment. The actual deployment takes an
appreciable amount of time as well – it must be lowered into the water
carefully, then its tether is constantly reeled in and out as it moves
away from the ship, ascends, and descends. When the ROV is in the
chemistry configuration, floats must be attached to the tether as it is
paid out. With all of these considerations, a chemistry dive that needs
to pump water for three hours gets scheduled for a five-hour block.
When the chemistry, microbe, and phytoplankton groups need to collect
water for their experiments, they must calculate the volume they need
and the rate at which the towfish or ROV can pump water. For example,
when Tim Shaw’s group needs 1,000 liters of water to calculate the amount of Radium-224 in the water, they
must consider that collecting so much water will take 40 minutes of
pumping from the ship’s seawater system, but 1.5 hours from a deepwater
towfish.
The best-prepared plans can still fall victim to weather and sea
conditions; the daily science meetings help work in changes that arise.
With so many people dependent on an accurate schedule, the daily
meetings help keep everyone on track.
— Amanda Kahn