He needed to learn how the engine worked, and now it could show him.

Whether or not the engines would work wasn't the issue.

He wanted to make sure that the engine was working and could be used to return early to the Earth if necessary.

You drive a car, not knowing how its engine works.

You will also be shown movies about how an engine works.

Thomas is told to take charge of the engines working on the lines around the town.

Furthermore, the engine worked well when new, but lost power after only a few hours of operation.

For example, an engine works bad when its fuel is not pure.

It tried moving at a right angle to its earlier course; the engines worked as they always did.