This is a Starfleet dreadnought. It is not an official ship, but is from www.asdb.net. It is essentially a Constitution II (aka Constitution refit) class hull with a third nacelle, heavier weapons and the original nacelle pylons have been made horizontal. This ship and its sisters were meant for war, but ended up sitting at a starbase for years. Eventually, Starfleet Command adapted them for exploration duties. Again, I have changed the colours in MLCad to white. It should be grey, but I think it looks better white. I have also added in grilled bricks for the nacelles instead of plain black 2x4 ones. This makes it more realistic (and I only have two black grilled bricks, with about ten grey ones).
Um, the dorsal Nacelle pylon is a bit too broad. >_>
Otherwise, excellent. When I searched for Federation, I hoped to find a TOS era one, but this is just as good. XD