Killer Octave Question

[A440A@aol.com]

Greetings, 
   The killer octave is usually supported by the section of belly rail that 
is farthest from buttressing.  The normal connection of the plate to the 
belly rail at the plate's "horn" provides resistance to outward movement, and 
the rails connection to the case at the treble end, likewise.  However, the 
ribs that must support crown under the killer octave bear against the 
bellyrail at its greatest unsupported span and it just might be one reason 
that this section of the piano loses its bearing first.  (The rib under the 
C5 on a Steinway O meets the bellyrail approx. halfway between the plate horn 
and the treble end of the rail).  
   Many other reasons could go into the equation, too.  

Ed Foote RPT 
www.uk-piano.org/edfoote/
www.uk-piano.org/edfoote/well_tempered_piano.html