Steam-Cogs have wide, open-air bays within which coal is stored. This coal serves as the fuel of the ship and is loaded into a furnace, the excess smog and smoke created by this process is then released through a series of short funnels on top of the vessel.[1a]
- Lava-Cogs: Similar vessels found sailing the lava rivers of Capilaria.
- Steam-Tankers: Another type of duardin-built trade vessel.