ROV Design and Electronics
Everyone loves to hear about the remotely operated vehicles, otherwise known as ROVs. They are super stars on Nautilus. However, even after hearing all the interesting facts about the ROVs, there were still some questions that I had about the electronics powering these machines. To gain a better understanding of how they worked, ROV pilot, Matt Slusher gave me a tour around the ROV garage and showed me the electrical “ins and outs” of how these machines work.
Hercules and Argus both need a source of power to run all the high tech cameras, lights, sonar, and, in Hercules' case, tools that are used to collect samples. So the question is, how does this happen? The answer is a combination of hydraulic and electric power.
A generator on board Nautilus supplies electrical power much like the power you would get at home from plugging a device into the wall. An electrical current moves from the generator through the ROVs, powering parts like the lights and the cameras. Hydraulic power is the use of fluid under pressure to cause movement, which is how Hercules' mechanical arm and tools are moved and operated.
Hydraulic pump on Hercules
My next question after hearing how these machines are powered, was “how is water kept out of these sophisticated electronics?” Matt showed me the thick metal casing on both Hercules and Argus, that is able to withstand 4,000, and 6,000 meters of pressure respectively. There is also an interesting feature for different sets of wires used on both the vehicles. Ordinary plastic tubing is used to run certain wires on the vehicles, but there is something extraordinary happening inside. All around the wires is food grade mineral oil. As the machines go deeper under the surface, the mineral oil is only slightly compressed and a compensator, which is basically a reservoir filled with more mineral oil and connected to the tubing, pushes mineral oil into the tubing to help it keep its shape and protect the wires.
Circuits on Argus enclosed in mineral oil
Last, I wondered what it took to maintain the ROVs and keep them functioning in the demanding environment of seas and deep oceans. Before every dive with the vehicles, an hour to an hour-and-a-half check is done, making sure that every system is properly functioning. In the off season when Nautilus isn’t collecting data, a team flies out to ship and does any repair or maintenance work that needs to be done. The engineering/technical team responsible for taking care of the ROVs also uses the off season as a time to engineer new features that might be useful on the vehicles. They are currently working on a design to make stereo and laser surveys go twice as fast in order to make Hercules more efficient and make better use of time.
Much applause goes out to the technical/engineering team who takes care of the ROVs. Their knowledge of electronics and engineering skills seem to be ready for anything that needs to be fixed, changed, or upgraded on these machines; and they do a fantastic job of taking care of these vehicles so that the science can continue aboard Nautilus.