I think the reason they didn't use taller ribs is because with compression crowing, the taller, stiffer ribs won't bend under panel compression and you won't get adequate crown. Isn't it true that the narrower taller ribs that you see on some older pianos were generally radiused? David Love davidlovepianos at comcast.net www.davidlovepianos.com Yes, I must say that I've never understood why for a long period makers with very few exceptions used, and still do, ribs of more or less square cross-section rather than taller and narrower bars providing the same or better stiffness for less mass. There was a time, however, in the very early days of the modern piano, when some makers did so, especially on uprights. JD
This PTG archive page provided courtesy of Moy Piano Service, LLC