SSN and SSBN infrastructure overlap hides different force demands

Is it sensible to include the SSNs with the SSBNs?

Shared nuclear infrastructure makes grouping them understandable, but dry-dock pressure and different missions make the tradeoff risky.

SSNs and SSBNs share much of the infrastructure needed to support nuclear submarines, but the two forces perform different missions. SSBNs must pass through dry dock to sustain the continuous deterrent patrol. The loss of other docks is described as having left effectively one available to the SSN force. That bottleneck helps explain the shortage of available attack submarines and the need to build more dock capacity. Grouping the fleets for their common infrastructure should still expose their competing maintenance demands.