Engine powered propulsion

Only ironclads may move under the power of their engines. Like galleys, ironclads may move at several speeds. An ironclad vessel depends upon the skill of her engineer as he coaxes the most possible energy from the temperamental engine that powers his vessel. The engine gets hotter and hotter as it works and at certain levels the engine may well explode. At the beginning of each turn the captain of the vessel rolls a d20. If the number rolled is equal to or less than the Heat Index of the vessel, the engine explodes.

Players may crew ships with a engineer to subtract from Heat Index.

The easiest way to keep track of a ship's Heat Index is to draw a circle on a piece of paper. As the ship's Heat Index grows, add markers of some kind (chits, stones, beads, pennies, etc.) to the circle. As the ship cools off remove markers from the circle. This way you can very easily and visually keep track of Heat Index without taking notes.