Question about Fori in Turku

Hi! I've been recently in Turku and we are delighted with this city with friends.

But we are still wondering about one thing and I hope that someone will be able to help us :)

How does to carrier Föri work?! We were using this ferry many times and we are curious how does it work.

Is it automatic (some mechanical way of working like crank) or is there some who drive it? We have seen a cabin on this ferry, but we couldn't see anything inside. Could you help us to solve this riddle? :)

There is a cabinet and someone control it from the cabinet