Kuhn Organ Builders Ltd, 2012
Restoration
www.orgelbau.ch/ope=801530
III/P/43
Germany, Bavaria
Stadtpfarrkirche St. Walburga
Distribution and system of Bittner organs
Since the beginning of the 19th century the instruments of the Bittner family of organ builders have formed a major part of the organ landscape in Bavaria. The relatively large number of organs built up to the 2nd World War is proof of the high esteem in which Bittner organs were held. Bittner, too, was forced by developments to change to pneumatic controls at the end of the 19th century. Finally, the construction of so-called Schüsselladen* prevailed with Bittner. Here, as with other types of chest with stop channels, each pipe has its own pallet. The leather membranes are glued on to a wooden, dish-shaped lamina. Today, unfortunately, we have to admit that this type of construction has not proved itself in any way. The problem is not the function itself but accessibility to the pallets. If the leather is damaged or if dirt falls on to the pallet, it causes an obstruction. All the pipes have to be removed before the fault can be repaired, which takes an enormous amount of time.
Technical modifications 1964 and 1992
Of course, with increasing age the faults multiplied. In 1964 the decision was therefore taken to remedy the defects in the pneumatic action (delay) by electrifying the organ. This entailed having a new console, and instead of the membranes releasing the valves, electromagnets were installed. In 1992 the massive base plates of the windchests were cut out to allow access to the valves from below. As a result it was no longer necessary to remove the pipes to reach the valves. In theory this was the right approach, but the practice left much to be desired. The chests were structurally weakened by this procedure. Right from the start they had not been adequately supported, and now there ensued subsidence of up to 3 cm! Naturally, this led to further defects. In addition, after almost 50 years of use, faults occurred in the electrical components.
Situation prior to restoration
However, it was astounding that, with regard to both design and the tonal qualities, the organ had undergone hardly any changes during its almost hundred years' existence. This says something for the quality of Bittner's pipe material.
In particular, the organ is important because it forms a unified whole with the interior of the church, was built specifically for the new church, and completed in the same year, 1913. Moreover, this is the largest of the organs built by the Bittner family organs that are still existant, and thus a prestigious instrument that deserves protection as a historic monument, at least on a regional level.
Approach to restoration
The Organ Committee received great assistance in its decision-making when it visited the restored Walcker organ in the Church of St. George in Ulm. In Ulm a similar situation had to be addressed in the year 2000. There was no wish there to restore the purely pneumatic system, or to retain the electric action. The following design was realized in Ulm:
- Restoration of the pipe work, tonal reinstatement of modified stops
- Restoration of windchests (cone chests)
- New console with mechanical couplers
- Mechanical tracker action to the valve windchests (Spielladen) in the immediate
vicinity of the windchests
- short pneumatic action from the valve windchests to the relays (Vorrelais) of the
windchests
- pneumatic stop action with magnets in the stop controls (capture system)
The realization of this design had a remarkable effect. The key action of all the manuals is extremely precise, yet the characteristic qualities of the pipe speech on cone chests are preserved as a result of the authentic pneumatic release of the valves.
Restoration
What was then more natural than to apply this concept in Beilngries? True, compared to the organ in Ulm, rather more drastic measures were needed. The Schüsselladen that had already been altered were converted into a tried and trusted system of membrane chests. The substance of the old windchests, with their upper boards, racks and pneumatic relays (Vorrelais) was thereby retained. Every organ pipe stands on the same place as prior to restoration. The valves are of course now accessible from the bottom of the chests. The structure of the organ was comprehensively improved by providing the windchests with additional support. The wind system, with all the old double-rise reservoirs, remained practically unchanged; only a new electric blower was installed. We followed Bittner's example in respect of the detailed design of the console case.
The mechanical key action is laid horizontally to underneath the windchests, and for the most part under the floor. The stop action was rebuilt as an electropneumatic construction. The switching system is operated electrically from the console to change-over relays sited at the centre of the organ. From these relays the pneumatic wind line is via lead pipes to the old stop controls (Registerstationen). In this way the inner workings of the organ still provide the artistic aspects of a pneumatic organ.
With this type of design the tonal qualities of this organ contrast with its solid construction and the long operating life of its technical design. Unquestionably, it required a great effort, but we are convinced that it was justified. An important, if not the most important, witness to the Bittner family of organ builders has been preserved. The church interior, organ design and sound, together form a whole and bear witness to their time.
* Translator's note: Literally «dish chests"
Translation: RS 2012
