Mr. Hem)’ is a League member and is Treasurer of the Capital Chapter. He is a naval architect and retired from the Naval Sea Systems Command i11 I 999 after 35 years of working in early stage submarine design and submarine-related R&D ma11ageme11t. His last position was as Head of Submarine Preliminary Desig11 and as Pri11cipal Naval Architect for the VIRGINIA Class.
Dr. George Sviatov’s interesting and stimulating article in the July 2005 issue of THE SUBMARINE REVIEW touched on a number of topics worthy of a reply.
Dr. Sviatov seems to believe that the US Navy keeps the names of the Chief Designers of its submarines secret. We11, George, it’s not that the names are secret; it’s just that we don’t know who the Chief Designers are either. The way the US Navy does submarine design there rea11y isn’t anyone who can be given that title. For example, let’s look at who was involved in the VIRGINIA Class design.
The Centurion Study Group was established in 1990 to develop notional characteristics for a new attack submarine to possibly replace the SEA WOLF class. In early 1991, NA VSEA began low-key concept design efforts to determine what sort of submarine (large or small, how capable, and at what approximate cost) would result from these characteristics. The initial design team included a Ship Design Manager plus the Branch Head and several naval architects from the Submarine Preliminary Design Branch.
Some time later, after considerable dialog between OPNA V and NA VSEA, many dozens of New Attack Submarine (NSSN) concept design studies had been completed by NA VSEA ‘s Submarine Preliminary Design Branch and similar design groups at the two submarine shipyards, Electric Boat Division (EB) and Newport News Shipbuilding Company (NNS). Eventually, the New Attack Submarine Program Office was established under a Program Manager. Among many others on his staff, a Technical Director oversaw the ship and ship system design and NSSN-related R&D and a Ship Design Manager oversaw ship-related design efforts. Another Design Manager directed the design of the combat system while the design of the propulsion plant was directed by NAVSEA 08, with most of the related propulsion plant design work performed by EB.
The Submarine Preliminary Design Branch moved into NSSN Program Office spaces to directly support the NSSN program and the Branch Head was given the additional title of Principal Naval Architect. Further NSSN concept design studies were conducted by NA VSEA and the two shipyards until, in 1994, the basic design of the ship was well established. With early-stage design completed, the Submarine Preliminary Design Branch returned to its own offices where it both supported the NSSN Program and began looking to the future. Further VIRGINIA Class design, through detailed ship design, was performed by EB and, currently, VIRGINIA class submarines are being built by EB and NNS in a teaming arrangement utilizing very large integrated modules.
So, George, who was the Chief Designer? Not the Principal Naval Architect. While he was chief of the naval architectural efforts during the early-stage design period, he had limited influence on ship operational requirements and the design of the many systems that made up the submarine. It wasn’t the Ship Design Manager, Techni-cal Director, or Program Manager either. While each, in turn, was chief of a broader span of activities, each was further removed from design and none had very much direct influence on the selection of operational characteristics. If this doesn’t make identifying a specific individual Chief Designer difficult, note that some of these manage-rial positions were held by more than one individual during the time period described.
The situation for SEA WOLF was somewhat similar to that described for VIRGINIA. In this case, however, there was Jess shipyard involvement in concept development but considerable involvement by both shipyards in the preliminary design and contract design phases. Detailed ship design was performed by Newport News Shipbuilding utilizing a propulsion plant design developed by Electric Boat under the direction of NA VSEA 08. While the submarines were built by Electric Boat, the renamed Northrop Grumman Newport News (NGNN) remains the lead design yard for the SEA WOLF Class.
“Prototype” for the VIRGINIA Class
Dr. Sviatov wrote, “the Navy decided to take as a prototype not the SEA WOLF but the Improved LOS ANGELES class SSN …. ” With respect to torpedo tube and vertical missile launcher architecture and number of weapons, it certainly is true that VIRGINIA is similar to later LOS ANGELES Class submarines. However, the VIRGINIA design started with the proverbial “clean sheet of paper.” In fact, there were many clean sheets of paper involved since, during the early-stage design phase, more than one hundred attack submarine concepts (baseline designs and multiple variants thereon) were designed and evaluated. Besides many based on a new propulsion plant (with the S9G nuclear reactor), concepts based on the existing LOS ANGELES, SEA WOLF, and OHIO propulsion plants were also designed and evaluated. And, to be sure that nothing was missed, a number of AIP and diesel-powered concepts were also designed and evaluated. Because of the types of questions that were being received from the senior leadership, it was deemed necessary to develop all of these concepts and to conduct cost and operational effectiveness analyses (COEA) for each of them.
So, while VIRGINIA and later LOS ANGELES Class submarines do have a similar weapon and launcher arrangement, this configuration was not an input to the NSSN design and many of the details are different. In fact, the earliest NSSN concepts, smaller and less effective than VIRGINIA, did not have this architecture.
Improved SEA WOLF concept
Dr. Sviatov’s proposed Improved SEAWOLF variant with 28 VLS tubes and 42 additional internal weapon stowage positions would certainly be a very potent attack submarine. However, his statement that one Improved SEA WOLF equals three VIRGINIAs is only true from the point of view of firepower and not for other performance attributes.
The proposed modification (an additional 375 tons of displacement) needed to increase SEAWOLF’s weapon capacity to a total of 120 is Dr. Sviatov’s rough estimate based on his considerable experience in submarine design; no design work or calculations were performed. Based on my own experience, such an increase in firepower would entail adding, at least, twice the proposed displacement increase. Nevertheless, I understand Dr. Sviatov’s position to be that his Improved SEA WOLF would be highly desirable even if the necessary displacement increase was substantially more than his estimate. Of course, the actual ship size increase can only be determined by doing the naval architecture, i.e., developing a ship arrangement and then performing the volumetric, weight, and ship balance calculations. (See “A Brief Lesson on Submarine Design” elsewhere in this issue of The Submarine Review.
Dr. Sviatov recommends that his Improved SSN2 l concept be considered for the US Navy’s submarine of the future and, in fact, this probably will happen! As in the past, studies for a future attack submarine for the US Navy are highly likely to include a wide variety of submarine concepts, including some based on SEA WOLF. Whether the future SSN resembles SEA WOLF (in any form) is less easy to predict. At this time, I would predict not, but the answer depends on a future world situation that my crystal ball cannot discern-and that is exactly why highly-capable, multi-mission attack submarines are the platforms of choice.
Measures of quality
In his discussion of alternative submarine designs, Dr. Sviatov utilizes tons of ship displacement per carried weapon as a measure of design quality. While this may be a reasonable measure for ships that are otherwise equivalent in their multitude of characteristics, it is not appropriate for grading very different designs. The objective is to provide the Fleet with an adequate number of effective yet affordable submarines, not to send the greatest number of weapons to sea. It should be noted that some current, very important submarine missions do not require any firepower.
A submarine of VIRGINIA ‘s size could be designed to carry many more weapons than VIRGINIA can currently accommodate and it would have more favorable tons of ship displacement per carried weapon ratio. However, to put more weapons;, something has to come out and the resultant loss of other capabilities (e.g., speed, stealth, combat systems) would lead to a very undesirable platform. Alternatively, through the development of advanced technologies, the size of various ship systems might be reduced thus providing more space for other functions (such as more weapons) in a given sized ship or, perhaps, reducing ship size. A proper balance of capabilities and cost is the goal to be achieved.
Bigger is better?
This has probably been argued since the first naval vessels were conceived-probably including biremes versus triremes. Absolutely speaking, it can certainly be said that “bigger is more” and, also, that “bigness” sometimes has its own detriments. Generally speaking, bigger is better when it comes to the performance of multi-mission attack submarines. Of course, when cost is entered into the equation, “better” takes on a whole new meaning where bigger and better may be unaffordable.
In conclusion, I thank Dr. Sviatov for his recent (and past) articles on submarine design. I hope that he will continue his writing.