The Heavy Demolition Ship is an upgrade of the Demolition Ship, an exploding gunpowder ship. In the parent game, Age of Empires II, this unit was playable and several civs could use it; now, however, it is only available in the editor (or by starting a game post-15th century).
Would be built at: Dock
Would cost: 120 Wood, 80 Florins, 4 population slots
Armor/Pierce Armor: 0/5
Special: +280 vs. buildings. Explodes.