Manned Sub for Argentina Coast Guard

On November 11, 2016, Posted by , In News, With No Comments

In 1973, Jacques-Yves Cousteau loaded two mini-subs and 20 tons of equipment on a railway to cross the Andes Mountains to see Lake Titicaca. Since then, no one has repeated his feat of diving with manned submersibles in the lakes of the Andes Mountains. In Patagonia, on both sides of the Andes and in Argentina and Chile, these lakes can exceed 400 m in depth.

Decades later, in 2012, the Prefectura Naval Argentina (PNA) looked into acquiring a manned sub for a very different purpose than Cousteau’s, to meet the pressing need to have modern equipment for salvage operations and scientific diving. PNA had started implementing deep-diving methods some years earlier with mixed gas diving and diving bells. This progressed to the use of ROVs supplied by a German company, Mariscope Meerestechnik, that came equipped with various types of instruments and were successfully used not only in the lakes of the Andes but also in the oceans around Argentina and even Antarctica.

Diving operations with open or closed bells are always difficult and expensive as they require a support vessel and lots of logistics. And while ROVs can perform incredible tasks and solve many problems underwater, there are many cases where a human presence would greatly simplify the work, if it were not for the limitations of the diving procedures, temperature, pressure, dive time and so on.

And so, PNA put out a call to Mariscope for a manned sub that would be multipurpose, multifunctional, transportable and not too expensive. Most important, the manned submersible has to be able to dive in the nearshore ocean environments and lakes of the Andes. Therefore, it would have to be able to operate without a large support ship. The Ocean Pearl submersible model from California-based SEAmagine Hydrospace Corp., for which Mariscope is the South America representative, best fit the specifications.

Ocean Pearl Sub

SEAmagine, established in 1995, is a manufacturer of small manned submersibles with more than 12,000 dives accumulated by its existing fleet. The company produces various models of its submersibles for depths from 150 to 1,500 m. All SEAmagine submersibles are classed by the American Bureau of Shipping (ABS) and are based on the company’s patented technologies that provide excellent operational logistics and strong underwater performance. SEAmagine’s submersibles have been used in the scientific, commercial and superyacht sectors and have also been used in National Geographic, BBC and numerous other film projects.

SEAmagine focused on constructing manned submersibles that can be launched unmanned as any tender, have a high floating freeboard, and can be boarded after launch. The company developed numerous patents over the years specific to manned submersibles and established a series of industry firsts such as its flexible buoyancy and flotation system, a novel clam shell cabin design, a high surface freeboard design, and construction of the first three-person spherical acrylic hull.

EAmagine’s submersible pilot training program was initially developed in 1999 in conjunction with the U.S. Coast Guard for its submersible operating for tourism in U.S. waters. This training program curriculum was the initial base that has since been expanded to its current international pilot training program.

Salvage, Search and Rescue

The applications for PNA’s acquired sub is twofold. First, the vessel is an additional tool for the Prefectura Naval for its search and rescue operations for both offshore and inland lakes. Second, the submersible is to be shared with the country’s scientific community for increased marine studies in the Patagonia and South Atlantic region. This dual usage of the manned submersible provides the country’s scientific community access to an economical HOV (human-occupied vehicle) setup while providing a powerful additional deepwater tool for the Prefectura Search and Rescue efforts.

In South America, many people drown each year carrying out professional operations (fishermen, aquaculture divers, salvage divers) and recreational activities at sea. Additionally, in the Andes, lives are lost in the lakes every year due to changing weather conditions and poor navigation infrastructure, coupled with careless behavior.

Local authorities are permanently involved in very difficult salvage operations, often carried out in locations with poor or nonexistent logistics. Therefore, transportable, high-end technology is a growing requirement. ROVs, AUVs and manned submersibles are tools that help to carry out these difficult tasks.

The SEAmagine Ocean Pearl model is ideally suited for this response effort by the Prefectura as it is sufficiently compact to be readily transported by its custom road trailer, enhancing rapid deployment abilities. The submersible’s patented flotation system allows for it to be launched from a regular boat ramp, which avoids requiring large cranes to be mobilized to remote locations with sparse infrastructure. Argentina has numerous high-elevation deepwater lakes that greatly complicate regular diving options. The 1-atmosphere Ocean Pearl submersible requires limited topside support vessel help when used shore-based or in lakes and can perform long deep-dive durations with limited topside infrastructure. A regular SUV truck can tow the submersible by road and launch it from a boat ramp or by crane. For a lake or close-to-shore operation, a regular tender with a 200 hp engine can act as topside control tower during the dive operation and can tow the submersible on surface to the remote region were the salvage is to occur.

For open-ocean work, the submersible is launched unmanned by crane and boarded after being secured at the aft deck. Even in harsh weather conditions, an inflatable U-shaped docking station is used as a large fender to handle offshore sea state conditions and allows for tenders to dock on either side of the sub to ensure a safe operation.

The submersible is equipped with wireless voice communication and with USBL navigation for topside tracking, also displayed on the pilot’s navigation screen. The submersible is equipped with dual-frequency forward-looking sonar, an HD underwater camera and at least one powerful robotic manipulator. The submersible’s equipment allows it to perform accurate defined search patterns underwater based on its navigation system. The pilot is in constant voice communication with topside, which constantly tracks the submersible’s GPS position that is then relayed to the pilot’s navigation screen. The pilot uses the dual-frequency sonar for target detection, then visually identifies the right target. The HD video system records the found target, and the salvage effort is performed with the submersible’s robotic manipulator. The submersible’s high payload capability gives the whole operation powerful underwater salvage abilities in deepwater with substantial bottom time. Furthermore, the fact that the submersible can perform multiple dives a day without being hoisted back on a ship’s deck enhances the productivity of the operation. All of this is performed with cost structures and simplicity that, depending on the circumstances, challenge more conventional methods.

Aquaculture, Scientific Studies

The growing aquaculture industry and scientific interest in the South Atlantic and South Pacific increases the necessity of new technologies. In Chile, Patagonian salmon farming yielded 1.4 million tons of production in 2014, showing evidence of a fast-expanding marine industry. In 1999, the first ROV was sold to operate in this industry, and Mariscope was a pioneer in this area, offering these new technologies. Now, ROVs are a common tool in marine harvesting sites.

The SEAmagine submersible represents a new underwater vehicle for Argentina’s scientific community. Much of the advantages the submersible offers salvage and search and rescue operations for the Prefectura applies to effective scientific operations. The ability for in-situ observations complemented with an array of subsea tools is an important asset for any nation’s scientific community. HOV operations are typically costly, the availability of assets is sparse, and this type of operation is often performed with submersibles with extreme depth ratings even when the scientific objectives do not require full depth-rated vessels. The Ocean Pearl submersible’s ability to perform shallow and deepwater operations in lakes and nearshore with minimal infrastructure or in the open ocean with a research ship provides an important new tool to the scientific community of the region.

Sub Design

The Ocean Pearl is 4.53 m long, 2.44 m wide and 2.25 m high. Dry weight is 3,250 to 5,000 kg (depending on depth rating), and the cabin payload is 227 kg. For propulsion, the sub has four brushless DC thrusters, with a maximum speed of 3 kt. Max mission time is 6 hr., with an additional reserve capacity of 96 hr. For power, the sub uses an AGM lead-acid battery with total power capacity of 28 kWh and charging time of 5 to 7 hr.

The submersible is a robust, safe and practical two-person (one pilot and one passenger) underwater vehicle with excellent fields of view for the occupants. The submersible cabin opens fully in half as a clamshell and allows for easy entry and exit. In surface mode, the patented flotation systems permit the submersible to float high above the water line with a high freeboard and low draft when docked to a ship. When submerged, the submersible is positively buoyant at all times and, should the thrusters stop, this submersible will gently rise back to the surface. Underwater, the submersible has high stability, remains horizontal at all times and does not roll or pitch. When the submersible is near the surface at the end of the dive, the flotation bladders are reinflated such that the craft floats back on the water’s surface and is then docked back to the surface boat or onto its trailer.

Testing and Delivery

The Ocean Pearl submersible was constructed by SEAmagine over a 10-month period in 2015 and 2016 under ABS engineering reviews and ABS surveys. The pressure testing of the submersible’s main hull and all its pressure vessels was performed under ABS survey at test laboratories on each individual unit prior to final assembly on the vessel. Sea trials of the submersible were performed in California off the coast of Redondo and completed with a final ABS-surveyed test dive to the submersible’s maximum depth rating of 350 m.

The submersible was delivered in Buenos Aires in May 2016 and was unveiled during a ceremony for the commemoration of the 206th anniversary of PNA, which was established on June 30, 1810. The setup of the submersible and the training of officers from Prefectura, as well as support personnel will be performed by SEAmagine instructors in southern Argentina in the months ahead.

Future Outlook

Marine operations increasingly use high-end technologies. Since Cousteau’s first dives, many mysteries of the ocean have been unveiled. Nevertheless, most oceanic areas are unknown and unstudied. With the increasing development of burgeoning economies around the world and the necessity of resources, the interest in the blue economy has become one of the main issues on the agenda of many governments. Chile and Argentina will play a central role in the development of marine research, operations and economy in the South Atlantic and South Pacific, paving the way for marine technologies to reach new dimensions.

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