Page 30: of Marine Technology Magazine (May 2013)
Hydrographic Survey
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Hydrographic Survey - Unmanned Surface Vessels was to design, build and deliver a vessel that was ?100% ready to go, where we could actually sell the boats to a customer,? said Bartlett.In the budding relationship between Al Seer Marine and 5G International, the initial target for the vessel was the UAE military, but as the project has evolved and markets explored, the collective believe the potential outside of military circles is much larger in potential. Focusing rst on the UAE military, however, has helped to create an end product that is attractive to both sectors. ?First and foremost, it has to be off-the-shelf, designed and built in the UAE,? said Bartlett. In part this har- kens back to the government?s desire to inspire and develop home-grown technology and industry. ?We are putting together a world-class project, [and there are other competitors in the world] but not in this country,? said Bartlett. ?There are of course competitors outside of the UAE, but we?ve got a better product, and we certainly have a better price.? Today the eet of USVs centers on three vessels, from the Sea Serpent, a small 3-m ?jet ski? version; to the Boomer- anger, the larger 11-m RIB; and the Eclipse, the top-of-class 11-m monohull.An outstanding feature of the top model, the 11-m Eclipse monohull, is a proprietary hybrid propulsion system. Powered by twin Fiat N67500 engines with a light commercial rating of just over 500 hp driving Rolls-Royce jets through ZF gears, the USV sports a top speed excess of 60 knots. But it is when the vessel slows down that it truly shows its value. Featuring a pair of 13kW electric motors, the proprietary hy-brid propulsion system gives the USV the ability to loiter for extended lengths of time, an intelligent system that allows the user, for example, to use only one jet at a time to hold station, effectively extending battery life and subsequently loiter time by eight to 10 hours.?A lot of the hybrid systems have been developed for rec- reational use to give you electric power out of the marina. But we are obviously looking for something that will provide hundreds of thousands of hours of reliable use,? said Keith Henderson, Director, 5G Marine Systems LLC, and the man that Murphy credits with identifying and bringing together the suppliers and components in quick, seamless order. ?The system is robust, with only minimal moving parts and with service after 20,000 hours at sea before anything has to be replaced.? The Fiat engines were selected because of their high power to weight ratio, in part, and the fact that they have been proven to be a successful performance power plant, particularly in the international race sector. The Rolls-Royce (KaMeWa) jets were a natural for Henderson, as he points out Rolls-Royce has its own hydrodynamic test cell, helping to make their units highly ef cient. The team submitted the hull design to Rolls-Royce, which in turn was able to provide speed predic- tion based on the engines speci ed as well as the gear ratio matched each boat?s waterjet. Henderson was also quick to point out the value of the ZF reversing gearbox in the autono- mous environment. ?By using a reversing gearbox, it not only changes the engine speed to the ideal speed for the waterjet, but also gives us the reversing capability, which is important if the waterjet gets clogged, you can back- ush it to free the obstruction. When you?re operating remotely it is a very im- portant feature.? ?One of the key advantages in using the hybrid is rst, you get a longer life in the sea,? said Aditya Nawab, Director, M.S. Robotics, Robosys Automation and Robotics Private Ltd., who brings robotics and computer code writing expertise to the team. ?Second, in mission speci c times when you want the USV to loiter, the battery management system switches between the engines and the hybrid motors (to ensure maxi-mum deployment time each mission. In addition, if on a mis- sion it actually runs out of fuel and runs out of batteries, it can actually home itself to recharge the batteries.? Automated Marine Laboratory The plan to use the USV in the scienti c and commercial markets is centered on the Automated Marine Laboratory con- cept, an expandable, easy to operate system based on antici- pated needs for marine biological and geophysical investiga- tion. While the primary mission in its hook-up with Al Seer was military, 5G has interest for an USV combined with the ability to deploy computerized environmental sensors and analytical systems with both the capacity for remote, hands-on and auto-matic, software-controlled, data collection. The core problem for which the initial systems are to be used is investigating factors relating to harmful algae blooms, but the base system with slight modi cation is suitable for a wide range of geo- logical, biological, chemical and radiological analyses. Today 5G is collaborating with marine scientists who have broad objectives for the types and quantity of data in which they are interested. The desired data includes, but is not limit- ed to, the collection of sensor data and physical samples from the atmosphere, the water?s surface, subsurface (the water column), the bottom and the sub-bottom. Objectives for this proprietary system include the capability for supplementing automated analytical work with onboard work performed by lower-level technical personnel where technicians may use the same equipment. This robotic laboratory system is a PC-based system for marine investigation of the atmosphere, water column and sub bottom samples where the collected data is time and GPS stamped and then logged for post-acquisition collection and/or transmitted electronically. As described, the system will perform the following basic functions (manned, remotely or entirely unmanned): - Through hull pump system to sensor manifold - In-line electrode and spectroscopic analysis - In-line digital microscopy May 201330 MTRMTR #4 (18-33).indd 30MTR #4 (18-33).indd 305/6/2013 10:55:56 AM5/6/2013 10:55:56 AM