This is the machine I use to start the draft when I light a fire in my steam engine.
It is a squirrel cage fan attached to an electric motor sitting on top of the smoke stack.
The smoke and hot gases have to travel horizontally from the fire box through the boiler tubes,
into the smoke box and up the stack.
Once I have steam, the exhaust from the cylinders or a steam blower up the stack
creates a partial vacuum in the smoke box and keeps the draft going.

Here are other "machines" from the challenge.