The basic rope swings aren't that unusual a ride, you get them at fetes and similar events along with the bouncy castle. It's a simple ride where two people sit opposite each other on a pendulum like pod, and pull ropes to make it swing.

This ride is a recreation of a steam powered set, all the originals died out due to their unpopularity. Instead of pulling a rope to make the boat swing you pull on a rope to engage a gear attached to a rotating shaft. Timing this right increases your momentum, so you start swinging back and forth.

One of the reasons for this rides lack of popularity was the engineering problems, as the shaft had to be set up very precisely, which was a problem on a travelling ride, that often needed to be set up on grass and bumpy ground. Another problem I see is that it doesn't really do anything a traditional swing doesn't do, making hauling around the steam engine a wasted effort from a showman's perspective. It never reaches more than a mild level of thrills, even when it reaches a good height. It feels more like a glorified playground ride than a true thrill ride.