Kaiserstiel
An emperor's stem (or “helmet pole”) is the inner tip of a tower structure (e.g. a church tower ) in timber construction .
It is the mostly wooden, vertical, uppermost component of the roof structure, at the top of which the rafters are pegged. In church towers, the wooden component is usually lengthened with a metal construction that carries the church tower's roof decorations such as a button , weathercock or other pictorial representations.
Due to its position, an imperial stem can no longer be reached from the inside in the case of pointed pyramidal or conical roof structures when installed. Since it is particularly at risk of rotting unnoticed through damaged roofing, it is made of particularly resistant materials (e.g. oak ).
In the classic national surveying , the extended helmet pole is used as a target point and coordinated in two dimensions. The height above normal height usually refers to the (middle) bead of the button.