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82 Before launching To identify unsafe areas and the appropriate clean-up tooling, a manned survey of the oil spill area is conducted using calibrated gas meters to identify noxious gases, with other tests for critical information on the nature of the oils spilled, such as their chemical volatility levels and viscosities, before the skimmer boat(s) are prepared for launch. The MSRC has 10 Kvichak skimmer boats stationed strategically around the US coasts so that the vessels can be deployed where needed in a timely fashion. For example, were a spill to occur in the bay of Delaware, skimmers from New Jersey and Virginia – most likely transported by trailer – could get there in 3 or 4 hours. “Once we’ve arrived at the launch site, safety pre-checks can be conducted and equipment configured very quickly for the product that needs to be recovered. There is very little preparation time needed before starting operations,” Swift adds. “As for permission to launch and operate the boats, we get those from the US Coast Guard pretty quickly, assuming it is safe to deploy the equipment of course. The key thing with oil spill response is to get it done as safely and as quickly as possible, to minimise the impact on shorelines, people and organisations.” The MSRC’s maintenance and training programmes make sure the equipment is ready to be deployed at any time. Very little work is needed on the vessel, apart from fitting the skimmer machinery with a suitable belt for recovering the spilled product. Powered by hydraulic motors, this effectively forms a conveyor belt that protrudes through a gap in the front of the bow, and the selected belt will vary in width and length depending on the anticipated thickness and viscosity of the oil. Once the belt is fitted and the skimmer is on site, the boat can be lowered on its trailer down the slipway nearest the spill site, and start heading towards its first mission waypoints. Autonomous skimming The boat skims back and forth along the waypoints, at about 1-2 knots, covering a section of the spill area in a similar way to how UAVs typically survey a crop field or area of countryside. With the Hemisphere GNSS systems, the skimmer boat has been found to consistently navigate well within 10 m of its assigned waypoint routes. Doing so is a key bar for success in these types of missions, which revolve around efficient and consistent area coverage, even for operations lasting many hours. The exact duration of each mission can vary depending on the work. If it’s to clean up a particularly thick oil spill, for example, the RRS might operate for 3-4 hours before moving to a collection barge to empty its holding tank, then returning to the oil spill to continue skimming. In the past, manned operations have sometimes been conducted with the collection barge coupled to the rear of the vessel, so that the holding tank can be emptied continuously without the need for intermittent 10-minute breaks to offload the skimmed oil. Swift says this approach and process could theoretically be automated for the autonomous skimmers. “It would actually be fairly simple, October/November 2020 | Unmanned Systems Technology Richard Balzano, deputy administrator of MARAD, operates the Sea Machines remote-helm control belt pack, allowing him to command the autonomous skimmer boat from shore We have a lot of projects that stand to enhance the use-case for autonomy in oil spill response, such as towfish to classify the oil