Embedment style towers (YAN common design) are set in a hole and adjusted by a level and transit sighted for the center line. Usually 3 winches (similar to a boat winch) with long cables are used for this adjustment as the tower hole is being poured full of concrete.

In the picture at the bottom of the page of the base (Riblet common design) the hole is around 8' deep. It's interesting to know that the embedded portion of this tower is commonly "guyed-off" by 3 winches as it is adjusted to the center line. Also an extension cord with a big stick can be used if no winches are available. This tower hole design uses less concrete and more of the earth under the tower to counteract the tower forces than a vertical embedment design.

- Ryan B

As Ryan and I have touched on, Riblet used a design wherein the weight of the towerhead was kept light so that the tower could lean more and place the load directly on the foundation. The load, in this case, offsets the weight of the tower. Hall, Thiokol, CTEC and Yan depended on the weight of the tower to offset the direction of the load, however, and placed more sheaves on the cap than Riblet. They put their towers completely vertical no matter the direction of load. Doppelmayr, Poma, and Heron designed their towers somewhere in the middle of this range, with slight tower angles on steeper sections and vertical towers on flatter parts. Doppelmayr in particular used the caternary (sag) of the rope to contain it on the tower.

I hope that the sketch on the right sheds a little more light on this. The solid lines represent the stronger force; the dashed lines the weaker (relatively speaking).

- John Holm