Cary L. Brown said:
It all depends on what you're talking about.
There are two fan-design "refit era" dreadnoughts which were created back in the 1980s... the Ascension class (based upon the Belknap... essentially a "light Dreadnought") and the Federation Class (refit). I think you're talking about the Federation(r).
The idea is that the secondary hull internal configuration is significantly different... mainly due to the presence of twin matter/antimatter reactors instead of a single one in the Heavy Cruiser. The Federation(r) has twice the power output of the Enterprise, in other words. It pays for this by giving up certain amenities (like the arboretum). The hangar space is larger, and supports both shuttles and combat craft.
The primary hull has a different bridge module with two docking ports instead of just one. However, the bridge itself is just about the same. The main difference there lays in B and C decks, which are set up as Fleet Command Operations facilities. The Dreadnought is typically the flagship of a fleet, and is commanded by an Admiral in the Fleet Operations Center, while the ship's captain runs the ship itself from the Bridge. This is why the B/C deck section is larger... just more stuff going on there.
The other differences are better known... the engine nacelles on the secondary hull are on a flat, "wing-like" pylon rather than on twin angled pylons. The nacelle on the dorsal is different, however, and most people get this one wrong. If you're modeling it, you need to make it from two INSIDE nacelle halves, not two OUTSIDE halves. Of course, then you'll have to add intercooler fins, but better than than have the wrong "engine grill" detail.
It's also worth noting that the positions of the "control reactor" ribs on the underside of the nacelles differs on the Federation(r) from that seen on the Enterprise.
Anyway, none of this is real so you can make it however you want... but if you're trying to do a Federation Class (refit) per the Fandom-created design, these are well-established by the folks who did the original designs.
That's all good information and some really fine work there Cary, but I'm guessing there is no canon Refit Dreadnought?
I'm very familiar with the FJ designs, but I'm really interested in any on screen ref to a Refit era Dread. Thanks again.
Did you finish that ship?