While past oceanographic work has been traditionally carried out on board yacht-like surface ships—and much will continue to be done so—a new trend has set in to employ the submarine as a vehicle of scientific research. Successful precedent for this is meager. In 1931, Sir Hubert Wilkins attempted to use a submarine for under-ice exploration. The obsolete U. S. submarine 0-12 (SS-73), renamed Nautilus and fitted with a topside superstructure shield and other equipment intended to enable her to slide under the ice floes, proved inadequate to the task. Material failures and insufficient endurance were her drawbacks. Nearly three decades had to elapse before submarine technology would be ready to support a major new assault on the under-ice problem.
Today, nuclear submarines navigate in safety beneath the polar ice pack, while their less-glamorous, conventionally-powered sisters probe elsewhere in the campaign to unravel the secrets of the deep. Recent press reports speak of a converted Soviet submarine, the Severyanka, fitted with portholes and laboratory facilities, exploring the oceans. Less well known is the story of U. S. submarines which are contributing to the advancement of our knowledge of the oceans. For most submarines, such scientific pursuits are subordinate to their primary military missions. Others are more or less regularly assigned to “less glamorous” experimental and scientific duties. Typical of these is the USS Grouper (AGSS-214), the oldest active submarine in the U. S. Fleet. She is designated as an underwater acoustic laboratory afloat.
Constructed under the stress of impending combat, the Grouper went down the ways at the Electric Boat Company in Groton, Connecticut, on 27 October 1941. Rushed to completion after Pearl Harbor, she was quickly deployed to the Pacific. Her many arduous patrols brought her no great fame or fortune, just an honest record of four confirmed sinkings totaling almost 18,000 tons of enemy shipping.
Following the war, she continued to serve useful but unspectacular roles. With the growing interest in submarine-versus-submarine operations she was classified as the Navy’s first killer submarine (SSK) in 1950. The lessons she taught were applied to the growing numbers of new or converted submarines entering service during the next decade.
By the late 1950s, the Grouper was showing her age. As a representative of the so-called “thin skin” class of fleet submarines, she could not claim the depth capability required of modern ships. Nevertheless, her services were much in demand. Operating under Submarine Development Group Two, the Grouper for several years provided services to the Navy Underwater Sound Laboratory. This work was characterized by installation and ripout of equipment on a “week on, week off” basis. It was apparent that such an arrangement did not permit the optimum performance of a long-range scientific program to meet the Navy’s operational needs in underwater acoustics and related fields.
In 1958, the Underwater Sound Laboratory undertook a program to correct this deficiency. The cognizant authorities in the office of the Chief of Naval Operations agreed to the sacrifice of military capabilities required in the submarine to convert the Grouper from a combat to an auxiliary submarine (AGSS), and to assign her to the research program on a full-time basis. To obtain optimum benefits from the ship’s employment, she was assigned jointly to the control of the Naval Research Laboratory and the Underwater Sound Laboratory. The two laboratories agreed on a scientific program of mutual advantage and prepared specifications for the ship’s conversion, which was done at the Portsmouth Naval Shipyard and completed in June 1960.
A key feature of the conversion was the installation of integrated electronic signal recording and processing equipment in a specially designed laboratory compartment. This equipment is designed and arranged to permit maximum flexibility in the selection of hydrophone and transducer elements or combinations of elements, the recording of both raw and processed data with high accuracy, and easy adaptability to the installation of new equipments and arrays in the future.
Space for scientific equipment was obtained by removing all torpedo tubes and much related equipment from the forward torpedo room. In this space a complete seagoing laboratory has been installed, with major experimental electronic equipment, an acoustically insulated sonar console room, workbench, locker and desk space, and sleeping quarters for six scientists.
Other interior modifications were minor, the most noteworthy being the installation of a new motor generator set in the former No. 7 main ballast tank. Since this tank was already as strong as the pressure hull, there were no problems involving structural adequacy. The generator set was needed to meet the high power demands of the new sonar equipment being added to the ship. Other modifications included the relocation or removal of bottom- side equipments to facilitate bottoming the submarine, and the provision of propeller guards to aid in berthing.
Topside, the Grouper presents a startling appearance with weird protuberances, constituting a combat submariner’s or hydrodynamicist’s nightmare. To the underwater acoustic scientist, however, these devices represent tools of utmost usefulness.
Among the special installations visible topside are a trainable transducer protruding from the bow, three streamlined “shark fins” mounted on deck, a long array of baffled- line hydrophones on the port side of the conning tower fairwater, and a “billboard” array known as “Colossus” on the after deck. Other pieces of equipment include two special receiving arrays, a Fathometer, a trainable deck hydrophone, and underwater telephones for communication with other ships during experimental cruises. So powerful are some of these devices that special protection is necessary to keep the acoustic energy in the crew’s quarters down to an acceptable level while the equipment is in use.
A number of additional installations of interest are continually being evaluated on Grouper, the details of which are still classified. Suffice it to say that findings in these fields are being fed back into the characteristics of next-generation sonar equipment, as fast as the data can be processed by the Navy’s laboratory computers.
Also worthy of note is the extent to which co-operation and integration of separate but related programs has been achieved in the Grouper. Under the joint control of two laboratories—the Naval Research Laboratory under the management of the Office of Naval Research and the Underwater Sound Laboratory under the Bureau of Ships—the Grouper embodies the amalgamation of basic and applied research pertinent to the differing missions of her two sponsors. As a laboratory vehicle, all extraneous considerations have been subordinated to her primary mission—underwater acoustic research and development. This singleness of purpose not only permits the most effective pursuit of oceanographic knowledge, but also assures the continuity of long-range research programs and reduces demands on the operating time of combat submarines.
The Grouper, the oldest of her kind, is at the same time one of a new and growing class of research submarines. As such she represents, if not a scientific “breakthrough,” at least an “order of magnitude” improvement in her particular field of effort.