At a park in St. George UT, there is an innovative design for a swing set that functions like both a swing and a teeter totter (seesaw). It is the product of the German firm Berliner Seilfabrik.
Unfortunately, the St. George set has been disabled. The vertical cables and disc seats have been removed. Why this is, I’m not sure.
To understand how the apparatus functions, metal chains and standard plastic seats were temporary installed.
The swing set was an instant hit. It requires a child (or adult) in both seats. And they rock back and forth, interacting with each other.
The children enjoyed the up-and-down motion, as well as the back-and-forth of a traditional swing. Even with the swinging motion, the children can’t hit each other. There is a swivel at the point where the seat cable attaches to the horizontal cable allowing for an independent spinning motion.