MM's are still around, they still use steam on the gator freighters, submarines and carriers. Its not nearly as large as it use to be. GSE's (gas turbine electrician) and GSM's (gas turbine mechanics) work on the gas turbine ships. Enginemen pretty much just work on Aux systems on the small ships since they did away with the diesel generators in favor of gas turbines. Electricians will end up becoming a much larger rate in the near future with "hybrid" ships in the works.
Maybe it was just the frigats that did away with the steam and changed to gas turbine.
yeah, well frigates were to be phased out in the next year or so, pretty much cruisers, distroyers, and the new LHD's. As expensive as fuel is getting i'm surprised they aren't going back to sails or coal fired boilers.