[Ed. Note: General Menez’s equivalent rank is Vice Admiral, Naval Constructors Corps.]
For years, any discussion about submarines of the future appearing in The Submarine Review was limited to “the best capable sub … ” and “…a 100 submarine force … “, leaving very little room for more innovative combinations. From time to time, reminiscences of conventional submarines were evoked under the pressure of Congress but they were quickly passed over with little attention to detail.
During this period, from experience gained in my own country, I was well aware that when the unit price of a single item (such as a submarine) increases to the point where, for several budgetary years, such investment could not be viable for a wealthy nation, people begin to consider and study in depth unforeseeable, possible solutions.
In France, we were confronted with such a problem in the 1970s, when we intended to build large attack submarines after a first batch of our SSBNs, but we finally turned to a far smaller design.
When one tries to keep a sufficient number of submarines on the inventory in spite of budgetary constraints, the tendency is first to design them more cheaply, which more or less means making them smaller and thus less capable.
But the inventory is not all: the aim is in fact to keep a sufficient number of submarines nt sea. This is a second, important aim which requires greater reliability and availability, bearing in mind that reliability. leading to more redundancies, may well run counter to the objective of a low-cost, smaller submarine. Balanced decision-making can, however. lead to the attainment of both goals. One can then obtain an even better availability, using two shifting crews for one boat, as is normal practice for SSBNs. This was introduced in the 1980s as soon as our attack submarines were deployed.
At the beginning of the 1990s after the near collapse of the SEAWOLF programme, the United States is now faced with a similar position.
There is no doubt that large reductions are to be made in present capabilities in order to achieve a lower unit cost for the CENTURION design. This must be done in spite of a possible increase in development costs, as new developments may prove necessary to achieve required compactness with easy maintenance.
But cutting capabilities is not an easy task, as was suggested in your July 1992 issue. CDR John Alden, in your October 1992 issue, was right to underline this difficulty. Capabilities can only be roughly quantified in relative terms: they cannot be measured, as a physical parameter can be, and cost effectiveness evaluations may therefore be misleading.
In such a process, it must be borne in mind that operational capabilities, although difficult to quantify, are closely related to physical parameters which are much easier to deal with as they can be computed accurately. Among these parameters, maximum speed (as well as maximum depth) is an essential factor to be taken into consideration due to its important impact on the design. Architectural factors, such as quantified values of pressure hull diameter, are also of importance (2 decks approximate 8m or 24 ft., 3 decks approximate 10m or 30ft.).
Let me recall tirst the influence of the maximum speed on submarine design. A submarine can be roughly modelled as a volume (V..) of military items (weapons, sensors etc.) whose mobility and services are produced by another volume (V,rop). For the sake of simplicity, these volumes are supposed to be shipsha-ped when added to each other and include all trapped water.
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This being established, it is quite clear that the maximum speed considered necessary at a design stage must be chosen carefully on well established, operational deployment schemes after a thorough analysis that cannot be found in open literature.
One often reads that high speeds allow for fast deployment in peacetime. This is debatable, as safety relies, inter alia, on gathering, at least from time to time, information on the surround-ing traffic. Maximum speed necessarily results in poor detection, even using the sonar in active mode. It cannot therefore be used all the time, except in open, traffic-free zones. On the other hand, short notice long-range deployments are unlikely in peacetime, as information is easily obtained and deployments set up well in advance. In this context, the Falklands War can be considered as an exception rather than the rule.
[Ed. Note: VADM Menez was in charge of the building programs for L ‘INFLEXIBLE, the improved French SSBN, and the RUBIS program for a nuclear attack submarine. He is a qualified submariner and an officer of the Ugion d’Honneur.]