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EVOLUTION OF MODERN U.S. SUBMARINES FROM END OF WORLD WAR ll TO 1964

Immediately after World War II, despite advice from the British Admiralty that we were wasting our time to develop a snorkel for two-cycle diesel engines, we did just that and completed successful full power trials on our first installation.

Many other problems were solved ;,1nd the installation of a snorkel became standard in the high priority GUPPY conversion program then underway.

GUPPY CONVERSIONS
(the Greater Underwater Propulsion Program)
The GUPPY conversions included primarily maximum streamlining and installation of the snorkel and a high capacity storage battery. Result: more than doubling underwater speed. One major problem was to develop effective ship control equipment and operation procedures to operate safely under the greatly increased speed and maneuverability of this dynamically unstable ship. COMSUBLANT made the first GUPPY, USS ODAX (SS-484), available for a month of sea trials. These trials provided the data necessary for developing ship control equipment and instrumentation for safe, effective operations of these GUPPY conversions of World War II submarines during that very vital post-war interval until new ships could be designed and built.

USS TANG (SS-563) Closs (Six Ships)
The first post-World War ll new design submarine, USS TANG (SS-563), was completed in October 1951. The shorter, more streamlined hull significantly increased submerged maneuverability. Increased test depth greatly increased both offensive and defensive capabilities. The major problem was maintaining the newly developed high-speed “pancake” diesel engines. Engines in three ships of this class bad to be replaced during their first overhaul with more reliable engines at substantial cost in lost operating time as well as money. This experience emphasized the calculated risk of committing a shipbuilding program to inadequately tested major components.

USS ALBACORE (AGSS-569)
ALBACORE was more a revolutionary than evolutionary development in submarine design. Its optimum streamlined hull form minimized submerged resistance. Its large, single propeller on the ship axis significantly improved propulsion efficiency. The combination provided a 50-percent increase in speed and a dramatic increase in submerged maneuverability. These outstanding results provided the proof needed to overcome the tradition requiring two propellers – long thought necessary for reliability, relocating the rudder and stem planes forward of the propeller, and eliminating the conning tower to minimize the fairwater (sail). These features were incorporated in the next new design submarines, both nuclear and diesel-electric, and became standard in all subsequent submarines.

USS NAUTILUS (SSN-571)
The NAUTILUS was every submariner’s dream — a ship with unlimited endurance. She was nearing completion and about to start dockside trials when I was transferred to Supervisor of Shipbuilding at Groton (Connecticut) as inspection officer.

Piping Problem
During propulsion plant bot water pressure tests, a small pipe connecting the two main steam generators bursl The reactor compartment filled with steam before isolation valves could be operated. Initial investigation revealed a split along a seam in a pipe which the specifications required to be seamless. The immediate problem was to determine whether this was a unique piece of non-specification pipe and, if not, what other pipe and piping systems were suspect. No pipe material identification marking system was in use. Seamless, cold-drawn steel tubing had been specified and ordered, but was not verified upon receipt nor was it marked for positive identification during fabrication or installation in the ship. Industry, laboratory, and university experts were contacted for nondestructive methods and equipment for positively identifying seamless steel tubing, but all in vain. Therefore, all steel piping systems were suspect

Problem Solution
Emergency orders for replacement piping for all systems were placed and expedited. Material control and marking systems were developed. A large section of the pressure bull over the engineering spaces was removed to facilitate more rapid transfer of piping in the largest practical assemblies, from the ship to a fenced-in area in the shipyard. There they were used as templates for new piping assemblies which were fabricated as soon as new, pedigreed piping was procured. The procedure greatly expedited fabricating and reinstalling the piping, but the scheduling and recordkeeping problems were horrendous. It was almost 4 months and $4 million later before the job was completed and testing resumed, even though we worked 21 shifts per week with essentially unlimited overtime. This “incident” revolutionized pipe marking and handling not only at Electric Boat and other submarine shipyards, but also in the piping industry as well.

USS SEAWOLF (SSN-575)
When construction of the second nuclear submarine, USS SEA WOLF, was authorized, then-Captain Rickover decreed that in order to expedite construction, it was to be identical to NAUTILUS, except where necessary to accommodate the different reactor and propulsion plant. Fortunately, I had not been informed officially of this mandate. As the submarine design officer in the Bureau of Ships Design Division, I was under the impression that each new design follow-on submarine should incorporate those changes which would improve its performance without delaying its construction schedule.

Earlier model basin tests for NAUTILUS showed that her bow would go under as she approached full power and that she could probably not achieve full power on the surface. I initiated model basin tests on a redesigned bow superstructure which showed a gain of 3 knots on the surface at a cost of only 1/10th knot submerged as well as provide a location fora more effective sonar array. The ship drawings were changed and trials of the completed ship verified the model test results.

Steam General()r Problem
SEA WOLF had a General Electric Co. submarine intermediate-speed neutron reactor utilizing liquid sodium as the reactor coolant beat transfer medium. During bot dockside testing, sodium leaks were detected in the superheater. Very little was known about caustic stress corrosion at the time this equipment was designed and constructed. Expedited tests of various materials at both Electric Boat and General Electric duplicated the type leaks in SEA WOLF equipment Design modifications were made, leaks eliminated and testing resumed successfully. In spite of these initial metallurgical difficulties with the primary plant, SEA WOLF subsequently operated for many months without requiring access for maintenance to the reactor compartment’s shielded lower level. Unfortunately, this problem created enough concern in Washington before it was successfully solved that Admiral Rickover announced that this reactor would be replaced with the NAUTILUS type at the ship’s first overhaul. More on this later.

SEAWOLF 60·Day Submerged Cruise
In October 1958, SEA WOLF completed a 60-day, 13,761 mile, continuously submerged cruise to uncover habitability problems which might arise during the 60-day patrols planned as a standard operating procedure for the POLARIS submarines then under construction. SEA WOLF surfaced off New London harbor and tied up alongside its tender where a news conference was scheduled. The first question a reporter asked was “How was the habitability during the record-setting cruise’!” Dick Laning’s response was “The habitability was great but the co-habitability left something to be desired.

SEAWOLF Power Plant Converswn to NAUTILUS Type
As mentioned earlier, Admiral Rickover had made the decision at the height of the SEA WOLF power plant problem to replace its nuclear reactor and main propulsion plant with the NAUTILUS type as soon as its first core was used up. One of the highest priorities in our navy at that time was ASW and these two nuclear submarines were by far the best targets for training our own ASW forces. As the SEA WOLF reactor was approaching the end of its useful life, I advised Admiral Warder that a spare core for the SEA WOLF reactor was available at General Electric and recommended that it be used to re-core the SEA WOLF reactor. I estimated that it could be done in 3 months instead of the 21 months estimated to replace its entire reactor and propulsion plant with the NAUTILUS type. This loss of SEA WOLF for ASW services at this critical time would be a severe operational loss. But Admiral Rickover had already directed General Electric to cut up the million dollar spare reactor core and reclaim the uranium.

USS SKATE (SSN-578) Class
The SKATE Class of five ships followed closely behind NAUTILUS. At the time its characteristics were approved by CNO, higher speed was considered secondary to increased ASW capability, and reduced size and cost Since ALBACORE trial results were not available at the time of the ships’ design, these ships were essentially scaled-down versions of NAUTll..US.

USS SKIPJACK (SSN-585)
USS SKIPJACK (SSN-585) was the offspring of the marriage of the NAUTIT.US nuclear propulsion plant and the ALBACORE streamlined hydrodynamic hull with single screw. Its 50 percent jump in speed for the same horsepower and load capacity, and its far greater maneuverability exceeded all expectations. She was the new submarine hotrod and gave the ASW forces fits. The newly developed high strength steel, called HYBO, significantly reduced the ratio of pressure hull weight to ship displacement and developed the fabrication technology for the next major jump in that very important operating characteristic, test depth, which was to be realized in the THRESHER class.

USS THRESHER (SSN-593)
The design, development, construction, and trials of THRESHER were among the most significant steps in the evolution of the “true” attack submarine. THRESHER’s keel was laid on 28 May 1958, only 3 years after NAUTILUS’ successful sea trials in 1955 had proven the practicality of nuclear submarines.

THRESHER was designed to incorporate significant improvements in submarine operational characteristics in three most vital areas — reduced machinery radiated noise, increased sonar capability, and increased test depth. The same type nuclear reactor used in the USS SKIPJACK (SSN-585) class was installed to avoid potential problems and delays inherent in developing a new type nuclear reactor. All of these very significant operational advances were achieved with a modest increase in length and displacement and at a negligible decrease in speed.

Initial Sea Trials — Pressure Hull Problem
THRESHER’s initial sea trials started on schedule and proceeded without undue incident until the deep dive. As we approached a depth of about half of test-depth, the David Taylor Model Basin representative, Pete Palermo, who was monitoring the extensive strain gage installation, reported that several gages indicated stresses approaching the yield point of the HYSO steel. The ship was brought up to 100-foot depth while the experts onboard studied the data. With so much riding on THRESHER, it was decided to postpone the remainder of the trials, return to the shipyard, drydock the ship, and examine the hull structure and the exterior strain gage installation. No discrepancies were found. Meanwhile, Pete, who had developed elaborate strain gage monitoring equipment to try to expedite the very time-consuming deepdive tests encountered on earlier submarine trials, was meticulously rechecking his equipment. About the time the hull inspection was completed, Pete approached me, the BuShips technical trial representative, with a very sheepish look. He confessed that one leg of his new strain gage monitor was grounded. He was able to repair it in record time and the sea trials were rescheduled. The deep-dive and fullpower tests were satisfactorily completed, but several of the scheduled trials were postponed due to the schedules of the two BuShips admirals aboard. To the best of my knowledge, some of those trials in the BuShips official schedule were never conducted. THRESHER had a very successful year-long shakedown cruise during which it was later reported that she had operated at test depth on at least 40 occasions.

Loss of the THRESHER — Naval Court of Inquiry
The loss of the TIIRESHER with 129 naval and civilian persons aboard, on 10 April 1963, while on sea trials after her post-shakedown availability, was the worst known submarine disaster in history. The official report of the Naval Court of Inquiry, which recorded 1700 pages of testimony over almost 2 months of hearings, concluded that “the most probable cause of the loss was a flooding casualty in the engine room due to a piping system failure in one of the seawater systems which, in tum, probably affected electrical circuits which caused loss of power.

What Happened, How Did it Happen, What Has Been Done to Try w Prevent a Repetition?

Immediately after the loss of THRESHER, a comprehensive review of the entire design and test data was initiated. Also begun was an extensive study of computer-generated ship trajectory traces through known or most likely points based upon SKYLARK’s reports. The most probable sequence of events appeared to be as follows. The ship was at test depth at slow speed (standard operating procedure (SOP) for deepdive trials). Immediately after the flooding was reported the captain called for full power, full rise on the control planes, and blow the main ballast tanks. The ship accelerated quickly and was well on the way to the surface when power failed. The ballast tank high pressure air blow system operated for a very short time but not long enough to overcome the negative buoyancy due to the flooding. It is possible the ship could have survived if either main propulsion power or the ballast tank blow system had not failed. With both failures she was doomed.

Why Werent the Sea Valves Closed Immediately?

To shut the sea valves would cause immediate loss of power thereby eliminating the ability to drive the ship to the surface by hydrodynamic lift forces on the hull and its control surfaces.

Why Did the Ballast Tank Blow System Fail? Immediately after the loss, a comprehensive review of the entire system design was initiated, as well as fabrication of an exact duplicate on one ballast tank control and blow system for installation and test in a mocked-up section of the hull. In order to install enough high pressure air storage bottles in the ship to provide the same standard blowing capacity of previous submarines of lesser test depth, the storage pressure had been increased from 3000 psi to 4500 psi. All system components bad been thoroughly tested individually but, as mentioned earlier, the test of the entire installation in the ship during initial sea trials had been postponed. The test of the mockedup system revealed that the control valves were acting like refrigeration expansion valves as the 4500 psi air expanded into the ballast tanks. This expansion caused the moisture in the high pressure air to freeze and block the airflow. The system and some components were redesigned substantially and became one of the major changes required under the very comprehensive “Sub-Safe” program for all follow-on ships of this class before they were authorized to resume operations at design test depth.

CONCLUSION Admiral Ned Cochran’s remark in June 1945 that submarines would experience the greatest development and offer the greatest challenges of any type ship was certainly prophetic. In Jess than 10 years NAUTILUS was at sea demonstrating the practicality of nuclear propulsion. ALBACORE was proving the quantum jumps possible in speed and maneuverability with her optimized streamlined hull and single propeller on the ship axis. Shortly thereafter these ship characteristics were combined in SKIPJACK, laying the foundation for the future trials. 1HRESHER’s keel was laid. TIIRESHER included major advances over SKIPJACK in three vital areas — reduction of machinery radiated noise, increased sonar capability, and greater operating depth.

W. D. Roseborough, Jr. CapltJin, USN(Ret.)

 

WHITHER THE LEAGUE?

Nearly four years have passed since an article, Whither the Leaiue. was run in the April 1984 edition of the REVIEW. It’s purpose was to determine just how extensively the silence of •the Silent Service” had been broken beyond the immediate ring of submariners themselves. It would appear an update is in order on this.

The Naval Submarine League Objectives imply a need for greater submarine awareness by the American Society, including those government agencies charged with procurement of submarines. These objectives take on greater importance in the face of tugging and pulling among services and warfare groups that will accompany inevitable budget cuts. Public attitude currently favors reduction of the deficit with defense taking a proportionate share. How this should be distributed is best left to the “experts.” Here is the “rub,” for without coercion from the electorate, legislators will nod to warfare groups with the greatest number and most persuasive “experts.”

Rationale for one League objective assumes that the American Society has little submarine knowledge and is given bad impressions about submarines due to bad information. In effect, submariners and submarines have an image problem which must be overcome.

In the TV airing of Herman Wouk’s War and Remembrance, the submariners were depicted as being led by men of questionable courage and integrity. In the same TV program, Nazi SS troops machine-gunned defenseless victims of the holocaust while later the crew of a U.S. submarine was doing the same to defenseless Japanese soldiers as they abandoned their torpedoed troop ship.

Though submarines performed well in WW II, the public imagination was captured by tales of battle in the Pacific skies and island hopping victories by the fore-runners of todays’ carrier battle groups. In the public’s mind, submarine involvement was non existent in all U.S. combat situations after ww II.

Much “turning around” of American society is needed in order to realize a second League objective — the influencing of legislators to back submarine procurement The public needs to understand the submarine’s viability and importance in war situations that might occur in the near future. The League’s efforts, mainly through the SUBMARINE REVIEW, can do much to develop a strong pro-submarine electorate.

A third League objective relates to “issues concerning United States submarines;” these must be expanded to include the adequacy of the Navy to carry out its mission in the face of the very real Soviet submarine threat. There is apparent doubt that carrier battle groups, the mainstay of our national maritime strategy, are survivable against a major Navy equipped with SSNs, and thus there are, in part, questionable current expenditures for battle group ASW protection. The purpose of the League is not to identify ways to reduce defense expenditures, but to clarify the League’s responsibility to champion the best interests of American society. A simple “buy SSN 21s” will not achieve this without sound arguments to show that naval objectives can be so attained and less expensively than through other means currently planned. It would appear the League is able, and by its charter, obligated to assist the public in identifying those planned naval expenditures which are for “soft” programs, and how offsets may be made to provide more submarines. Well validated positions by the League in these matters strengthen its credibility. Indeed, if points made in the quarterly REVIEW and by speakers at League symposia are valid. then much good ground is here for the plowing.

League membership strength is substantial nation wide. It is a force to be reckoned with, especially if members are active among civic organizations. There is always a need to fill agendas with good speakers. If made to understand the importance of ASW and submarine warfare as America moves into the 21st century, civic group audiences are known to be quite vocal in the discussion of issues with legislators. A meaningful League slogan in addition to “every member get a member” is “every member avail himself of local targets of opportunity.”

So then, Whither the League? How far has the ring of “silence” extended beyond our own members? Will opportunities be exploited through the media with the “submarine message” being extolled? Though a great forum, the League must reach beyond the pages of its quarterly. Perhaps the day is not too far off when the opening line of a major network evening news cast will begin, “A spokesman for the Naval Submarine League today expressed concern that our developed Naval posture may not be equal to the real submarine threat.” We can only hope.

D. M. Ulmer

Naval Submarine League

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