I always took the TNG Technical Manual's designation of "surveyor" as being the proper designation for a science vessel, with fully-staffed laboratories for long-term planetary and stellar research. In comparison, a "scout" was for more general short-term reconnaissance & border patrol missions, especially at the outer reaches of Federation space. While both surveyors and scouts can perform intelligence-gathering and data analysis missions, surveyors tend to be more science-oriented and can be deployed to study a specific planet or star system for weeks, if not months, IMO.
As far as "explorer," I viewed that as a largely TNG-era term for a ship that investigates and deals with the unknown, regardless if it's in totally uncharted space or in Earth's immediate backyard.
Based on the fact that the Antares in "Charlie X" is also referred to as a cargo vessel, I think it is likely that survey ships are also used to transport resources from planets and areas of space they've surveyed.
ship registry numbers got made based on size
Looking at the FJSTM, I noticed that ships with 1 nacelle have numbers that start with 500 and go to around 640, ships with two nacelles start with 3801 and to to around 3940, and ships with two nacelles in secondary hull start with 1700 and go to 1842. I think, if one regards 3801-3940 as an error and instead substitutes 1000-1140, we get an interesting system that is almost like that used by some automakers for trucks:
500's-scouts/destroyers-1 nacelle
1000's-support vessels-2 nacelles
1700's-curisers-2 nacelles plus secondary hull
This leaves around 500 numbers open between the classes that Franz Joseph developed, plenty of space for the Grissom, a scout, to have a number like 638, which, despite having two nacelles, fits the system be being a scout with a number between 500 and 1000.
So NCC numbers very much can be sequential within a group of similarly-sizes ships, and still also suggest the vessel's size/role.
Container Ship
- Used to haul standard bulk containers
- Containers may be bulk cargo, liquids, transport pods
- Can be made from downgraded line ship
Transport
- Used solely for personnel movement on larger scales
- Larger units used for colonization support & evacuations
- Smaller often make “rounds” on fixed routes
- Most slower; some “fleet transports” for planetary assault ops
- Smaller commanded by LT or LCDR; larger by LCDR, CDR, occasionally CPT
- Can be made from downgraded line ship
In both these cases, I think there is evidence that Starfleet can and sometimes does use older ships for transports/cargo/etc. There are ship models of the Enterprise-A used in TNG with sideways nacelles and the window areas removed and replaced with what appear to be cargo bay doors. Going back to the FJSTM, I was surprised to se how many of the Transpot/Tug ships (which resemble the Miranda of later productions), were named after human explorers. Is this meant to imply there were vessels used for exploration that were later converted to tugs?
Hospital Ship
- High speeds for quick response
- Minimal arms for defense only (except fleet ships)
- High number of transporters; high capacity
- Large shuttle/cargo bays; can be used as triage areas
- Dedicated medical wards, research facilities
- Equipped with special destruct packages to prevent contamination
- Heavily compartmented for danger isolation
- Commanded by CDR or CPT with medical background
- Comfortable crew/patient spaces
- Starbase-based at times
I had forgotten to consider hospital ships earlier, but I think that converted ships with high capacity, like surveyors, cargo carriers, and also outdated cruisers, would work as hospital ships without a class dedicated to them.
Dreadnought and Battleship are nearly redundant
A lot of classes are beginning to seem redundant to me, due to overlap, despite how fun it is to imagine what some of them might be like. In fact, the roles cargo carrier, tanker and surveyor from Sternbach's list might all be carried out by a ship like Franz Joseph's Ptolemy, and even further reduce the need for many designed.
Rather than develop ships for numerous roles, like battlecruiser/heavy cruiser/cruiser/light cruiser, I am beginning to get the impression that Starfleet uses fewer class designations (like maybe just the six I mentioned), but is developing new versions of ships for those six roles with each generation of starship.
For example, the Ptolemy can cover perhaps three of those roles, but eventually newer Miranda's are made instead, and later Centaur's, and later..Nebula's?? Starfleet might need to send all four classes into battle, in which case, the four classes, in that particular battle, might get assigned as Ptolemy-cargo carrier, Miranda-destroyer, Centuar-light cruiser, Nebula-heave cruiser, based on that battle at that location.