Suitable in size and armament for a stand in for a Space Marine Battle Barge for the defunct tabletop wargame Battlefleet Gothic. Main hull has armed and unarmed variants. You can find the bombardment and normal turrets in:
I am not affiliated with GW in any way! Please don't reupload this on Shapeways and the like for commercial use (though you're welcome to upload them to get them printed that way for yourself).