Unmanned Systems Technology 018 | CES show report | ASV Global C-Cat 3 USV | Test centres | UUVs insight | Limbach L 275 EF | Lidar systems | Heliceo DroneBox | Composites

26 Dossier | ASV Global C-Cat 3 USV controller and a propulsion pod, so customers do not really have to worry about them beyond ensuring that the batteries are securely clipped in place – using competition car-style over- centre clips – and properly charged. For everything related to the payload, the focus is on the gondola. Payload facilities In the centre of the gondola is a manually deployable and retractable pole that terminates in a plate for the customer to mount the sensor. Passing vertically through a slot in the deck like those used for dinghy centre boards, in its retracted position the pole allows an operator to launch the boat with the sonar safe between the hulls, wade into the water with the boat and pull on a rope to lower the pole to its operating depth and lock it in position with a pin. Made from 6061 aluminium, the pole has an extruded foil profile originally designed for the kind of adjustable sun blinds fitted externally on tall buildings. It fits snugly in the slot and is stiff enough to eliminate any movement that might disturb the sensor. So far, ASV has integrated the Norbit iWMS multi-beam sonar onto the C-Cat 3 but will integrate any others that customers ask for, so long as the boat is capable of housing it. Other likely candidates include sensors from Reson and R2 Sonic, which have been used on other ASV boats. For above-water sensors there is a flat area on top of the gondola to which equipment can be through-bolted. As yet, there is no bespoke mounting facility, so customers would have to drill their own mounting holes, but in future the company might provide a plastic adapter plate that can be swapped with different hole patterns for various sensors. The company is also waiting to see how similar various Lidars, for example, are in their mounting requirements. “Lidars seem to come in everything from a small puck to great big things with inbuilt GPS and so on,” Daltry points out. “There isn’t a standard mounting plate that would cover them all – yet.” As catamarans have high stability margins, mounting sensors weighing up to 10 kg would not cause problems, he says, and there is scope for more weight on top of the gondola if some payload weight were removed from inside it. With a multi-beam sonar and a Lidar, the vehicle could gather survey point clouds below and above the water around some complex maritime structures. For example, the company has the prospect of a job under an oil pier and tanker berth near a refinery, where the customer wants to survey among the poles, piles and cross-beams – a dangerous environment into which to send people in boats. On-site assembly ASV wanted to provide the payload, endurance and survey speed in a vehicle that could be disassembled into modules of a size and weight that can be moved around manually by only a few people. Many of the waterways in which the C-Cat 3 is intended to operate don’t have easy vehicular access, so the idea is February/March 2018 | Unmanned Systems Technology In the retracted position, the payload pole allows the boat to be pushed into shallow water with the sensor safe between the hulls, then deployed by pulling on a cord (Author’s image)