When it comes to working submerged offshore, I have to be considered one of the most fortunate. During my twenty-year career as a U.S. Navy Submariner I had the enviable opportunity to be in a command or senior support position with the US Navy’s submarine Research & Development communities. These positions allowed me to be personally involved with cutting-edge technologies and equipment. On many occasions, technologies developed for strict military use have migrated to the civilian sector. INS technologies and AIP systems are just two examples. The most promising naval technology to become available for commercial applications, is the use of diesel powered manned submarines. The last diesel powered submarine operated by the US Navy was the USS Dolphin (AGSS 555), a deep diving research vessel, in which I served as OOD, Diving Officer and Chief of the Watch for many years. That vessel, as well as the NR-1 (Nuclear Research Submarine) the Navy’s other research submarine, before retirement, performed applications such as submerged structure inspections, seabed mapping, hydrographic and geologic studies, as well as search and coordination.

The offshore industry until now has had to rely on ROVs to do the same tasks that these submarines perform. Ironically it was the Navy that pioneered ROV development and in many cases uses them today. Autonomous Submarines, utilizing diesel or nuclear propulsion, eliminate the need for a tether and thus sever the requirement of the costly surface support ship. Besides allowing for covert operations, the submarine proved to be a safe and ideal platform to conduct intervention, inspection and real time assessments with engineers and scientists on site. Although both NR-1 and USS Dolphin have done work that may be considered commercial in the past, being active military submarines, access was very limited and highly restricted. As an ROV operator as well, I can personally attest to the advantage of being physically at the intervention site as opposed to viewing a screen fed by a remote camera. Even the high definition 3D sets cannot replace a technician or engineer being physically on site.

Manned submersibles (not submarines) have been around since the early 1960s and were used extensively by the offshore industry until the 1980s. Those in the industry long enough will recall the benefits that submersibles provided over the ROV platforms in primary use today. The ability to have rapid 3-D assessment onsite, by an engineer or researcher cannot be completely achieved remotely. However submersibles were limited in size, typically carrying only 1 to 3 individuals in cramped quarters and were reliant upon costly and weather sensitive deployment vessels. Since ROVs and manned submersibles share similar support requirements, operations for both are restricted to relatively low Sea-States. However, submarines with their primary power plants (again diesel or nuclear) operate independent of surface ships, they typically can perform projects regardless of Sea-State. Submerged endurance and autonomy are many times greater than those of manned submersibles. Submarines are streamlined and have the necessary space onboard for larger batteries, which provide submerged power for the diesel variants. Without a tether and operating independently, submarines have the ability to outperform inspections conducted by ROVs with regards to time and effectiveness, particularly if the target area is large. Submarines are by nature AUVs that can perform ROV tasks.

Autonomous submarine technology is available to the offshore market. Kokes Marine Technologies LLC, a U.S. based company, is chartering their vessels, the Corsair (RS-1) and Constellation (RS-2) diesel powered inspection submarines. Not openly publicized, an RS Series Submarine has been used for over 12 years on various pipeline installations, intervention, inspections and survey projects. Like the Dolphin and NR-1 these vessels operate with a high degree of independence, and are not as sensitive to Sea-State as the other platforms discussed earlier. Both submarines are 48′ in length and can easily be mobilized to any part of the globe that clients require. A 400 NM range is provided by reliable diesel engines. Submerged autonomy is provided by the conventional use of advanced submarine batteries. The RS submarines have a large 1.1 meter hemispherical view port in the bow and one 180-degree view port / hatch at the top of the sail. Low light / high resolution cameras are used to document the inspection sites, and a multi-frequency Side Scan sonar system coupled to the boat’s INS (similar to those used on nuclear submarines) provides a mapping accuracy that meet exacting industry standards. The RS series submarines are GL certified to operate in depths up to 300 meters making them ideal for continental shelf and mid-column projects worldwide. The submarines are equipped with a full galley, including refrigeration, stove, sink and microwave. In addition, a sleeping compartment, head provide both comfort and livability to the crew on long missions. The daily charter rates for the vessels are approximately one third less as compared to a working class ROV, operating in similar depth ranges. Operations are conducted without a deployment vessel, eliminating that cost and weather sensitivity issues.

The RS Submarine’s large hemispherical view port is ideal for one or more engineers to view the project scene directly. Video cameras allow for documentation of the site as well as inspection reviews. Side scan sonar compliments the vessel with survey capabilities. The RS Submarines typically operate in Sea-State six without concern. The crew and observers board in port and the submarine pilots out to sea under independent and reliable diesel power. The 400nm autonomy can be further increased with at-sea refueling. A crew of six includes the contractor’s choice of 4 personnel. Project managers can have their engineers and planners onboard to document and effect rapid judgment on the progress of their projects.

The RS Submarines open new doors for the researcher and offshore commercial engineer alike. Operations are no longer restricted to a small quarantine on the sea floor. The crew can be transported to several dive locations in any given day, spending more quality time submerged and engaged in work. Tasks and phenomenon can be viewed in real-time, where rapid judgment and assessment can be made. Operations such as pipeline and cable inspections can be performed simultaneously with the installation, allowing for corrections to be advised before problems escalate. The RS Submarine can provide assistance to ROV, Hard Suit and Commercial Diving operations as well. An engineer, who must otherwise wait for the description of the submerged project’s status, can now safely and economically inspect as the diver works. The generous energy budget of the RS Submarine allows for a variety of hydraulic tools to be used, including multi-function manipulators. Hard Suit operators can be transported from one dive site to another without the need to surface and benefit by having an engineer or group of peers in close proximity to assist in documentation or intervention. Qualified individuals at the target scene can assess projects that are sensitive to marine archaeological, environmental and biological issues. Cable and pipeline installations, to name a few, are often hampered by lengthily environmental concerns and often are challenged or litigated in court. Expert testimony is more acceptable in such cases when real-life evidence is presented, as opposed to remotely acquired data or third party interpretations. Proof of the existence or as important, proof of the absence of certain marine life, can be more accurately determined by the professional at the dive location and the reports and testimonies generated by this approach are logically given more weight.

The RS Submarine is an ideal platform for naval and security operations. ASW and prototype system testing can be efficiently performed for a fraction of the cost normally allocated to such tasks. The RS Submarine has ample reserve buoyancy and is capable of carrying a myriad of bolt-on or internal ancillary equipment. Hydraulics as well as various voltage supplies and computer interface protocols are available for a broad range of applications

During the past decade GL and ABS have formulated classification rules for engineering, construction and maintenance of Manned Submersibles used in the tourist sector. This has created a segment, which over time has proven to be among the safest in the marine vessel industry. The RS Submarines were designed, built and are maintained to these proven and safe industry standards. Their classification and compliancy to SOLAS standards allow worldwide underwriters to economically and competitively insure their operation.

Although at first glance the RS Submarines may present as new technology, in reality they represent the culmination of over 100 years of development and 12 years of direct offshore experience. The RS-1 and RS-2 provide the offshore community with cost efficient and practical options that until recently was afforded only by a few select naval organizations.

Mr. Martin is a retired career US Navy Submariner. He is a former OOD / Diving Officer onboard the US Navy’s Deep Submergence Research Submarine USS Dolphin (AGSS 555) and had direct responsibility for monitoring and providing mission support to NR-1. In addition to his DSV and ROV Pilot certifications, Mr. Martin is an expert in deep submergence operations and served on the staff of Submarine Development Group ONE, Submarine Squadron TWO, Submarine Group TWO and SUBLANT.