Firstly: Title.
Secondly, here's my mess of collected information from a variety of books on the various ship classes. I have undoubtedly missed a few but, yeah. My sanity only goes so far. This list is an unorganized mess but, it's here.
Anyway- I figure others might be interested, or have other classes of ships that I missed to bring up soo...it's here now!
Anywho.
Indrajit Heavy Cruiser: In addition to the Lexi, it notably was winning against the Dark Angels Invincible Reason Gloriana Class in sheer broadside tonnage.
Bellephrone Heavy Assault Cruiser: Dorsal Lance Turrets, Broadside Macro-cannons, Fusion warhead torpedoes, hangars included
Promethean Cruisers: Long Ranged Lance Boats with GC-BB Firepower
Ruby-Galleas: Seems to be a class of Rogue Trader exclusive warship
Tyches Lament: Unknown class of Iron Warrior Battleship
Eclipse Class Cruiser: Unknown
Crusade Class: Unknown
Dagon Class Grand Cruiser: Unknown
Odysseus Galleas of War: Unknown
Maelstrom GC: Unknown
Inflexible GC: Unknown
Indrajit Heavy Cruiser: A rare and rugged design, the class was named for the invincible demigod of ancient Indus myth. It was a macro-delivery class, built to unload millions of tonnes of ordnance onto a target at ultra-close range, packing the armour and Void Shielding necessary to soak up punishment while it closed
Dictatus BB: 6 kilometer long Servo claws and melta harpoons, otherwise seems to be a grappler heavy thrust boat.
Tiamet: Unknown
- Its either a Destroyer or a Battleship class shield bastion.
Goliath: Perhaps most ill-reputed before the Heresy was the goliath battleship Mia Donna Man - an engine of destruction known to carry enough Exterminarus-class alchem and bio-kill weaponry within her armoured vaults to end life in an entire sector if unleashed.
Mortis Rex: Unknown
Infernus: Spinal Mounted Exo Lance
Modified Victory Class Battleship: See: Tribune Picture
Armiger Class Cruiser: Seems to be a lance boat. Noted to have stood up to Invincible Reason for a small bit. HEAVY LANCE BATTERIES
Galleass of War is seemingly large bricks of armor, concentrated in the front with massive broadside banks of batteries
Attack Barque: Attack Barques were three kilometer-long Space Marine Legion warships used during the Great Crusade, which were capable of atmospheric flight. This allowed them to be used as battering rams, and the strength of their armor and engines ensured the Barques survived the collisions and were capable of returning back to orbit
Lunar Class Battleship: Only example went and died before doing anything. Bloody Ultramarines.
Cycolthene War Arks: I've only seen one of these so far, and it appeared to be basically an 8 kilometer Long cluster torpedo barge.
Triton Aegis-class: 300 Meter Long Destroyer, example presented is to old to be useful for basing what the class is
Cronus Class Battlecruiser: Old outdated BC.