Today’s post involves a simple conceptual clarification concerning the difference between modularity and weapon modules. Too often, the two terms are used interchangeably when, in fact, they are completely separate concepts.
ComNavOps has gone on record numerous times about the fallacy of modularity (see, "Payloads Over Platforms" or "The Myth of Modularity"). However, a friend reminded ComNavOps about the concept of weapon modules. In this context, perhaps a better word than “module” is “pit”. A weapon pit is a standardized and designated space for a single weapon system that is built into the design of a ship at the outset. During the course of the ship’s lifetime the weapons that fit that pit can be changed as weapons are upgraded or as weapon requirements change. The pit, then, is limited to weapons. Of course, there’s no inherent reason why a pit couldn’t be devoted to some other function – a sensor pit, for example.
The modular pit is typified by the Spruance class which was designed with pits that could be upgraded throughout the life of the class. The MEKO family is another example.
ComNavOps is fully supportive of the modular pit concept although there is nothing that inherently requires such an approach. While the ability to swap out what’s in the pit is an attractive capability on paper, the reality is that ships very rarely do so. In fact, off the top of my head, I can’t recall an instance of any warship from any nation actually doing so. There probably is an example somewhere but the frequency of occurrence is clearly very low. In the USN, at least, the combination of early retirements and diversion of funding to new construction effectively precludes pit level upgrades. Thus, pits are pointless. On the other hand, they cost little to include in the design and have no significant impact on design, hence, my support or, at least, lack of objection.
In contrast, modularity, as the term is used now, refers to the ability to completely change the function of the carrying platform by changing the module. The LCS is the obvious example of this in the USN. This topic has been thoroughly covered so I won’t rehash it.
As I said, just a simple exercise in clarification of terminology.