Orgelbau Th. Kuhn AG, 1998
Kath. Kirche Herz Jesu
Orgelbau Th. Kuhn AG, 1998
The east wall of the church's central nave has two large openings. Below is the impressive «inner portal» and above, a large «window» in the form of a pointed arch opens up to the inside of the tower which lies behind it. This upper opening is, optically and acoustically the ideal position for an organ which should preside over the whole church. The old and narrow bridge between the lower and upper openings was, however, to weak to carry the weight of an organ of appropriate size. For this reason there had never been an organ in this location. The previous instrument had to be fully set back into the area of the tower, which severely restricted the transmission of its sound within the building.
By means of a well thought-out steel construction, the weak points in the construction could be strengthened and restored making it possible to place substantial parts of the new organ in front of, and under the arch. Admittedly it was impossible to fit all four divisions (Hauptwerk, Solowerk, Schwellwerk and Pedal) within the total width of just six metres, so the manual divisions had to be arranged behind one another. In addition, the organ was not intended to cover the complete opening of the pointed arch so as to profit from the light shining through the back tower windows which had previously been concealed by the old organ.
These circumstances and considerations eventually led to the following arrangement of the divisions in the façade: in the middle, above the organist's platform with the console, is the Hauptwerk with the pipes of the Principal 8 '. In order to place emphasis on this central point, four plough-like pointed towers, jutting out, were incorporated. To the sides of these, the flats of the Pedal Organ create a marked edge. Here the longest pipes of the entire organ can be found, the imposing pipes of the Principal 16 ', over five metres long. The rest of the organ is arranged behind this, out of view. Directly behind the Hauptwerk and at the same height is the Solowerk. It stands within the opening in the east wall. Further back, in the tower itself, is the Schwellwerk.
So that the divisions situated further back are not compromised in sound, all three manual divisions were built together as a single, compact unity. Due to these measures, an even radiation of sound was achieved, so that all divisions are clearly audible from the central nave, whether or not they are positioned in front of, in or behind the pointed arch.
With the arrangement of the pipes in order of length in the flats of the Hauptwerk, the resulting step-wise pattern follows the curve of the pointed arch of the middle nave which lies above. The large Pedal flats, on the other hand, create a contrast to the form of the arch with their curved connections to the ceiling, whilst the pipe lips are arranged in a line following the arch of the portal.
The oak case is treated in oil wax and is intended to keep its light colour. With its numerous front pipes it is finely proportioned and is in keeping with the ribbing of the arches and pillars.
The specification is aimed in the direction of symphonic music, even though the relatively small number of stops, being only 29, would tend to contradict this notion. Through sharing the stops between three manuals (besides the Pedal Organ) a much more versatile use of the available tonal colours is achieved.
One of the main considerations was the sharing of the usual stops of a large Hauptwerk between a smaller Hauptwerk (I) and a Solowerk (II). When coupled, the desired large Hauptwerk is still made available, but in separating the stops of the Solowerk, many possibilities for tonal differentiation, whether in polyphonic music or in the employment of a solo voice are achieved. The Schwellwerk (III) is also by no means just a Romantic attribute. Thanks to its tonal presence in the room it can be employed as a manual division for the performance of trios or coupled to the pedals as a cantus firmus voice.
We also aimed for differentiation between the various reed stops. Whilst the reeds of the Hauptwerk and Pedal Organ lean more towards the German ideal in terms of tone colour, those of the Solowerk and Schwellwerk are based on the classical French tradition.
The couplers are assigned a particularly important role in this tonal design. The blending of sound of the foundation stops needs to be possible in every thinkable combination, and this without any detriment to the tuning. Added to the usual six couplers are a sub-octave coupler III-I. This helps achieve an almost linear dynamic range in the Schwellwerk, and this not only for spectacular forte passages but also in a finely differentiated piano range with soft and colourful flute and string stop combinations.
The fully mechanical systems, not only in the key action, but also in the stop action, may at first be viewed as a hindrance and restriction on Romantic registration principles. However, five mechanical toespoons for single reeds and the Hauptwerk Mixtur, together with the three manuals, achieve a high degree of tonal flexibility, as required by the organ repertoire of the 19th and 20th centuries.
Translation 2008: SJR