Abstracts in the tracker action of pipe organs
Another innovative development is the use of carbon in pipe organs. When the organist plays a key, a small valve is opened under the pipe by means of bars (abstracts) and hinges. The wind circulating in the organ is consequently released and forms the sound. This whole system of abstracts, hinges and valves is called the tracker action of the organ. The abstracts of a mechanical tracker action are usually made of wood, but a modern solution is to use carbon.
Using carbon has a number of advantages: first of all, the favourable mechanical properties of carbon: during play the abstracts are continuously subjected to torsional stress. The high fatigue resistance and high stiffness of carbon ensure a longer life of the abstracts. Moreover, the use of carbon makes playing the organ lighter. Because the abstracts often have to give traction over longer lengths, the use of a light material like carbon has advantages. Finally, carbon has good resistance against temperature fluctuations and moisture, which is favourable to the playability in damp spaces (such as old monasteries).« Back