You have to get the pressure to -5 and then turn the wheel thingy.
A heat source heats up the water in a a contained unit, and pressure builds up in the contained unit and steam flows out.
they worked by getting hot and they would start to boil and that's how it got the ship to move. that's why the old ships idid not really go that fast because it would take a while to get the boilers...
By taking fuel, coal, wood ,oil, gas, electic and transfering it to make heat such as steam or hot water
All boilers are not coil type think of the pork chop steam boilers AKA cast iron sectional