The Aktaeus is the most recognisable of the Ordinatus Minoris created and operated by the Mechanicum, a super-heavy transport designed to carve a path through the stony heart of a world to deliver its cargo of warriors to the centre of the battlefield. Known to the armies of the Emperor as the Imperial Mole, this vehicle is employed primarily as a siege engine capable of rendering even the most formidable fortifications pointless by burrowing beneath them.
There are a range of huge dioramas in Warhammer World in Nottingham. One of them involved Imperial Titans attacking a T’au base.
Including the powerful Warlord Titan armed with Mars Pattern Warlord Titan Apocalypse Missile Launchers
The Apocalypse Missile Launcher is a Titan-class support weapon capable of firing volleys of missiles to saturate a wide target area. The superior elevation and mobility of a Battle Titan as a firing platform makes the Apocalypse launcher a surpassingly flexible weapon. When mounted in pairs on the Mars pattern Warlord Titan, the Apocalypse launcher becomes even more deadly.
Supporting the titans was a Mechanicum Ordinatus Ulator.
A rare and truly arcane weapon system of staggering power, the Mechanicum Ordinatus Ulator is of the smaller classes of Ordinatus, but nevertheless is one of the most potent war machines at the Imperium’s disposal.
The Ordinatus Ulator carries a trio of Volkite Culverins as its secondary armaments, but its primary weapon is the Ulator class Sonic Destructor. A terrifying weapon whose origins lie in the shadows of the Age of Strife, the Sonic Destructor generates a wave of annihilation that wreaks havoc across the battlefield.