Exercise 5
Coal
A car is very different from a steam engine. You simply switch the
engine on and away you go. A steam engine can't move until it has enough steam. The steam
is produced by boiling water. A huge fire boils the water. Lady Ingrid's fire has to burn
for 2 hours before there is enough steam to move the engine. If she was a large locomotive
it could take 8 hours to make enough steam! The fire is left burning all night so that
there will be enough steam in the morning.
It is the job of the fireman to keep the fire burning. He has to shovel just the right
amount of coal into the firebox. On a large locomotive travelling at high speed, the
fireman has no time to rest - he spends the whole journey feeding the fire.
As an inspector, you will have to check that the fireman shovels the right amount of coal into the firebox.
Lady Ingrid's bunker holds 360kg of coal. She uses 90kg of coal per hour.