The principle of diversification is followed in many .fields of human endeavor. For example, wise investment managers and the heads of large corporations diversify in order not to be totally dependent on one investment or a single product, while sociobiologists attribute the very survival
of the human species to the diversity provided by sexual reproduction.
Thus 1 t is not surprising that in the era of iron, steam and fossil fuel, when surface-ship navies ruled the seas, the major naval powers of the world applied diversification to their fleets. The battleship, which reached its greatest potential in the Dreadnought type, was the ultimate weapon, followed in descending order by heavy curisers, light cruisers, and destroyers. Some navies went even further and
built battle curisers, which were not as heavily armored as battleships but were faster. Again,
the motivation behind this diversification was survival.
Along came the submarine, or submersible as it should be termed due to its limited underwater
endurance, and naval planners treated it as just another type of ship there being little variation within the category in either capabilities or purposes, (excepting “some” oddities such as the French Surcouf).
Although the fact was not admitted for many years, the arrival on the scene of modern aircraft and true submarines radically changed the survival potential of surface ships. The impact of aircraft on naval warfare is in itself a monumental study. It is not the subject of this paper. What concerns us is the true submarine, with its unlimited underwater endurance, high speed, and low detectability.
Beginning with Nautilus the U.S. Navy, probably because of long-established habit, continued to look upon the nuclear-powered submarine as just another type of ship — a more capable submersible, that is. While there were periodic advances in hull and power plant designs, SSN’s continued to be general-purpose ships armed with the same weapons and built to carry out the same missions. It was not until the introduction of the Polaris missile that a different type of submarine designed for a specific new mission came into being. SSBN’s represented the first step in the u.s. Navy’s diversification of its submarine fleet.
But since the advent of the SSBN neither the introduction of new weapons nor the requirement to
conduct new and expanded missions has resulted in further diversification of U.S. Navy submarines.
This is particularly interesting because, from published reports, it is apparent that the Soviet Navy has accomplished a considerable diversification of submarine types in recent years. At the very least, this should give u.s. Navy planners pause to study new weapons and the relative importance of expanded roles and missions in order to evaluate the advantages of taking a further step toward submarine diversification -keeping in mind that it will require ten years or more of development and acquisition before that decision can be made operational.
What, then, would be the advantages of diversification? First, it would provide new options to submarine force commanders; and, secondly, it would present new and difficult problems to opposing forces. And what are the problems in achieving these ends? Primarily, they are those involved with examining new concepts, selecting the most attractive ones and developing these into a submarine designed for optimum performance of a selected mission (or very few missions).
It would seem that, because antisubmarine warfare is considered the most demanding and important of all attack submarine missions, ASW would be the most likely area to examine for possible diversification. Of course, the idea could be aborted immediately by lack of an innovative approach, and later by inadequate development. But with the emphasis demanded by such an important program, a submarine designed for optimum ASW performance would not be the lower half of a high-low mix. Rather, it would be supreme for its selected role in all geographical areas, including Arctic, shallow and restricted waters.
On the other hand, superiority in missions other than ASW would be conceded to the generalpurpose
attack submarine, the capital ship of the Navy, which would retain its own excellent ASW capability. The overall result would be an increase and improvement in the total ASW capability of the submarine force and the U.S. Navy.