The ability to keep wind at a constant supply and pressure is important to the overall tone of the organ. How precisely you manage the pressure is an item of artistic discussion. A slight flex in pressure is desirable for an artistic touch. However, huge dips or wind pressure drops under heavy demand are not desirable and are often considered poor pipe organ building design.
Reservoirs are devices inserted between the blower and the windchest. The reservoir will be either a box with a lid hinged and sealed with leather or rubber cloth or a wedge assembly similar to large fireplace bellows. The reservoir has a valve controlled by the moving lid to regulate the amount of wind passing through reservoir while maintaining a regulated pressure on the wind. Standard or wedge reservoirs are usually mounted beneath or near the windchest.
The exact determination of winding systems is determined by the layout of the organ and the available space. Our company prefers the use of box or wedge reservoirs. With proper sizing and regulation, they provide a desired flex or gentle push to the wind for better tonal life in the instrument. Flex or gentle push is not to be construed or confused with winding systems that create bouncy, unsteady or nervous undulations in the wind that translate into unsteady tone in the pipe speech.
Schwimmer lids are wind-regulating devices that are mounted directly to the bottom of the chest. The Schwimmer lids are compact and highly efficient and use the windchest itself as the reservoir. Properly designed Schwimmers, while compact and efficient, can sometimes seem sterile in the management of wind supply and pressure.
Tools for the Church Organ Committee.
For a compilation of in-depth information ranging from industry standards and descriptions to the format of purchasing a pipe organ, please download our Tools for the Church Organ Committee.