Page 20: of Marine Technology Magazine (October 2010)

news

Under-Ice Mission for Bluefin-21 AUV

Last month, a Bluefin- 21 Autonomous

Underwater Vehicle (AUV) owned by the

Alfred Wegener

Institute for Polar and

Marine Research (AWI) was sent out on an under-ice mission and retrieved valuable data that could shed light on climate change.

The AUV was deployed by AWI and Bluefin crew members from the R/V Polarstern about 79° north.

Equipped with an AWI- developed water sam- pler payload, the vehi- cle traveled under heavily packed ice col- lecting 22 samples in discrete time intervals for later analysis. The

Bluefin-21 AUV is a 3000-m-rated system capable of traveling over 70 km at a speed of approximate- ly 3.5 knots. A mission is configured on

Bluefin’s Mission

Planner software and loaded onto the vehi- cle computer via an

RF link. Once launched into the water, the AUV carries out the mission completely autonomously. Vehicle status is transmitted back to the operator computer via acoustic communications. Upon recovery, data is downloaded and the water samples removed for analysis.

The AWI cruise began in Longyearbyen,

Spitsbergen on the

June 30. It ended in

Reykjavik, Iceland on

July 29.

The ABS Brazil Offshore Technology

Center, in partnership with the Federal

University of Rio de Janeiro (COPPE/UFRJ), has begun work on its first research project – a multiyear study on the application of torpedo piles as an alternative mooring anchor system. The concept has been developed by Petrobras for continued use offshore Brazil. The study will examine state-of-the art techniques available to simu- late soil conditions and determine a set of requirements and criteria that address the holding capacity and structural strength of torpedo piles in operation. The study is expected to result in the development of a rational approach for the class review and approval of the proposed mooring system.

The study was launched in early August and is expected to be completed by February 2012. According to Christiane Machado,

ABS Senior Engineer, Technology, upon completion of the study a report with rec- ommendations to the industry will be issued together with guidelines for the design and use of torpedo piles. The torpedo pile has been recognized as a cost-effective alternative to traditional anchor-based mooring sys- tems. It has been considered for use in moor- ing floating production systems and mobile offshore drilling units (MODUs). The pile is installed in a free fall operation from a sup- port vessel. Some of the key considerations surrounding the design of offshore founda- tion systems, in particular those using torpe- do piles, are the uncertainties related to the determination of holding capacity values.

The determination of relevant parameters of soil characteristics and the final installed position angles, together with the safety fac- tors to be considered in the design, will be addressed in this study, explains Machado. “We want to provide a set of parametric equations to better estimate anchor weight, installation limits for penetration distance and angles and check the adequacy of the installed pile holding capacity.” Since the establishment of the ABS Brazil Offshore

Technology Center was first announced in

May of this year, it has been fielding propos- als and considering research projects intend- ed to support the development of new tech- nologies for offshore facilities, particularly those in Brazilian waters.

Recently, the Center applied for Brazilian governmental funding through FINEP (Research and Projects Financing) to support the development of new technologies for pre-salt related engineering. The work would be carried out in partnership with

COPPE/UFRJ and Rio’s tank testing facility,

Lab Oceano, and be focused on the develop- ment of Rules and guidelines for the global performance of closely moored offshore units.

ABS in Brazil

Torpedo Piles Take Center Stage

Black Laser Learning Makes DVD on AUVs

The ability to map the ocean floor, lay cable, locate shipwrecks and hunt mines are just some of the varied needs required by marine-related industries around the globe. As advances in underwater technology continue to grow, so, too, does the need to understand and work with the myriad of vehi- cles available today. But demanding schedules and tight budgets can make it difficult to attend live training courses. Additionally, making the time to research manufacturers can be challenging. That’s when training via DVD comes into play. Hosted by Dr. Art Trembanis of the University of Delaware, and narrated by Capone, the AUV program starts with basic definitions and concepts, building into a detailed discussion of vehicle capabilities, sensor packages, survey strategies and field operations.

It’s a progressive, step-by-step overview that helps personnel make well-informed decisions on what product will suit them best. www.blacklaserlearning.com 20 MTR October 2010