Feature 3 | ROVS AND AUVS UTEC unveils “floating AUV garage”
Te survey specialist’s ‘Jumbo’ system enables crew to launch and recover up to seven AUVs directly from the ship, removing the need to deploy additional RIBS or daughter craſt
UTEC for an upcoming project in West Africa, could provide a cost-efficient, time-efficient and safer means of deploying AUVS directly from larger survey ships – thus sparing crew the added hassles and risks of securing an additional, smaller daughter craſt from which to launch the vehicle. The LARS, which has tentatively
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been named the Jumbo, was initially developed as an in-house concept to help fulfil an anticipated pipeline inspection contract in African waters. Designed to serve as a low-logistics “floating garage” for seven AUVs – including Teledyne’s modular Gavia model – the LARS, at first glance, resembles “a piece of scaffolding with floats”, Trevor Pugh, UTEC’s global technical authority, tells Ship & Boat International. However, he continues: “If we had made it from scaffolding, it would have been a lot heavier and needed a lot more [and/or bigger] floats.” Instead, the company contracted a
design company to strike a fine balance between making “such a large frame as light as possible” while ensuring that the structure remained “strong enough to carry the weight of the Gavia AUV out of
the splash zone without structural failure.”
new AUV launch and recovery system (LARS), custom-built by offshore survey specialist
UTEC’s in-house- developed AUV launch/ recovery system has a draught of approximately 1m
Tubular components Te system comprises a series of flanged and bolted steel and aluminium tubulars, to simplify assembly/disassembly and to make it easy to stow on board. “Te design is based on bolted members, so the LARS breaks down to individual members of 4.2m max length,” Pugh continues. When in use, the LARS has a draught of approximately 1m. “Global navigation satellite and USBL positioning systems can be mounted on the LARS to seed the AUV’s inertial navigation system positioning,” he says. UTEC had previously developed a
narrower LARS, which was more suited to shallow-water launches. However, Pugh recalls: “Tat system was fine for launch, but needed a RIB in the water for personnel to guide the AUV into the LARS for recovery.” Despite requiring a larger crane for launches, he says, the new, wider LARS “means we don’t need to put a RIB in the water, solving operational and
Sunny outlook for ROV demand
Demand for work-class ROV services is expected to total nearly US$7 billion over the course of 2019-2023, claims analyst Westwood Global Energy Group, which also predicts that ROV utilisation could “return to 50% by 2023”. However, ROV manufacturers will have to ensure that their products offer maximum uptime and optimal operational efficiency in order to woo offshore operators, especially while day rates remain at “cyclical lows”, the group predicts.
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safety issues related to personnel working in small open boats.” Tis is particularly the case in areas prone to rough weather and harsh sea states. As well as enabling personnel to launch
and recover AUVs from the ship, the LARS can also be utilised for subsea launches, or launched from a rig that has been towed to the offshore work site, Pugh adds.
Future versions? At present, as mentioned, the system is primarily an in-house device for UTEC, though there could be scope for a wider audience. “We only have one, but obviously can build more when required,” Pugh explains. “Clearly, it could be used for AUVs of similar or lighter weight, though a significantly larger AUV – such as a [Kongsberg] Hugin – tends to have a ramp-based LARS. In theory, our LARS could be scaled up, but I think the buoyancy would be huge.” The nature of the system’s design
may also make it difficult to rush out ‘off
the shelf ’ variants: as Pugh puts
it, “unfortunately, the design requires aluminium welding and there are a number of challenges related to weight vs. strength…so it is not as easy to fabricate as we would have liked.” As a scalable, bespoke concept, however, the LARS would appear to be an interesting development in the ongoing drive for increased safety and reduced operating costs within the offshore renewables and oil and gas segments. SBI
Ship & Boat International November/December 2018
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