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Stopped & Half Stopped Pipes


Mr. Henry Willis

This talk is to draw attention to the variety available to the discerning and artistic designer and also to half-stopped pipes of a most interesting nature that have been well-nigh forgotten.

The oldest type is that of the Gedackt (German), Bourdon (French). Illustrations:-
1. Of wide scale and solid tops, these pipes were tuned by the ears, later, canister sliding tops were fitted for tuning purposes. In the 16th century, in Germany, these stops were made of fairly heavy metal-in France, of lighter metal and with a higher tin percentage-thus illustrating the difference in tonal ideal and requirements.
An average scale at 2 ft. is 1¾ in. with a quarter mouth.
A lovely stop worthy of recapture.

2. The Quintade is of similar construction to the Gedackt but some four scales smaller: the mouth is kept low for a mild but distinct production of the first upper partial, the twelfth, and the bass was bearded in the old style. Much used in Germany but not in France-and seldom in this country-the stop, if correctly placed, has charming characteristics.

3. The Quintaten-similartype-4 scales smaller than the Quintade, a lower cut-up and a strong development of the twelfth give this stop an individuality of a striking nature. Use in this country has been appreciated in recent years and in 16 ft. pitch it forms an admirable double for a Choir Organ.

4. Rohr Flöte. This is of identical construction to the Gedackt but has chimneys, the French example being the Flute-à-Cheminee. Originally with solid tops and tuned by the ears-sliding canister tops are now usual.
The use of the chimney gives a lighter tone and curiously enough there is a trace of the octave. This stop is of the half-stopped variety.

5. Koppel Flöte. Of Gedackt construction but the top is extended in conical form with the "chimney" hole one-fourth the diameter of the main body of the pipe. The encouragement of the even numbered harmonics, which struggle to come through, gives the stop the lightness and liveliness which is depicted by its name-to couple.
The scale is approximately four scales larger than the Gedackt. Chiefly used in 4 ft. pitch.

6, Spill Flote. Of similar type to the Koppel Flöte-but six scales smaller - the length of the conical upper part is much greater being approximately- of the total length: the bore of the top of the chimney is one-half of the cylindrical body-the characteristics of the Koppel Flöte are present and accented; the tone approximates to the Gemshorn with added stress on the development of the twelfth.

Stopped and half stopped pipes
Click for larger image.

It is recognised that all pipes of conical construction approach the half-stopped variety, and such stops have great value because of the greater development of the twelfth as the conicality increases.

In this short talk I have endeavoured to draw special attention to the use and possibilities of half-stopped pipes especially of the Koppel and Spill flöte variety that are well worthy of consideration.

Extract from :- Journal of the Incorporated Society of Organ Builders. Published 1947