By Angela Russell, University of Adelaide
To conduct the science needed to unravel the mysteries of the ocean and its influence on ecology and climate, you need to take operations up a notch. Some may think it’s simply a matter of dangling a few instruments over the side of a boat but let me tell you…RV Investigator is no ordinary boat!
RV Investigator is a 93.9m long, 18.8m wide ship, powered by three diesel engines and two electric propulsion motors (Figure 1). Purpose built for CSIRO, RV Investigator puts Australia at the forefront of ocean research globally, conducting oceanography, geoscience, atmospheric and marine science, from the Antarctic ice edge to the tropics. Along with a phenomenal team of engineers, navigational crew (Figure 2), technical crew and IT professionals, the ship’s impressive technical capabilities allow us to enhance our investigations to an advanced level.
The vessel is like a mesocosm of the world! It accommodates 40 scientists and support staff, and twenty crew. RV Investigator generates around nine megawatts of power, enough electricity to power a small suburb! It even completely biodegrades all sewerage onboard, so as not to contaminate the samples. Obviously, there is no room for error here, so engineers work around the clock to maintain the workings of the ship, keeping replacements for every part of the machinery. Engineers are also equipped with a workshop to repair engine parts or scientific units on the fly.
A brief overview of RV Investigators ‘kit’ includes advanced sonar technology which emits acoustic signals in a 30 km wide beam in water depths to 11.5 km to reveal, in 3D, seafloor features such as deep-sea canyons and mountains. We used this swath data and ArcMap (GIS) software to create a high-resolution bathymetry map of a previously unmapped, deep sea canyon we traversed (Figure 3). A drop keel underneath the ship (Figure 4) can be raised or lowered into the water column. This allows water samples to be recovered without interference from the ship.
The ship is specifically designed to an international maritime classification called DNVSilent-R. This means RV Investigator is one of the quietest vessels in the world. Radiated ship noise interferes with acoustic signals, so by building a quiet ship, the performance of the equipment used to monitor the marine ecosystem, and map the seafloor is maximised. Roll stabilization also improves our use of scientific instruments, such as microscopes and balances, which can be tricky on a moving ship.
The logistics behind the location of sample sites and each sample collection is a strategic masterpiece and one aspect of our mission I was particularly in awe of. The Chief Scientist works in close collaboration with the Technical Operations Team, Integrated Ratings Crew and Master of the ship, to design each procedure in a way that ensures the safety of the crew and their scientific instruments, to meet the research objectives and to optimise sample quality. It really is a symbiotic relationship, in that each is part of the team that is integral to the other (Figures 5,6,8).
One of my highlights of the voyage was in the operational room on the internal communication system during deployment of the CTD unit (Figure 7). It was my job to request the CTD stops required to collect water samples remotely at different depths, up to the Integrated Ratings crew (IR crew) located in the ‘Cat House’. This area is where the winch and boom are managed, and where all the ships cameras are simultaneously viewed. This gives IR crew the ability to visualise the CTD going over the side, while viewing the winches below deck as it descends. Once the unit was in position at its lowest depth (it went down to 4500m), I fired the closing of each of the 24 sample bottles on the return journey with a single mouse click.
As students of the CAPSTAN voyage, we are spoilt with the level of expertise and state-of-the-art technology provided to us. It’s been a once in a lifetime experience that I will be forever grateful for.