Detuning bass strings was Re: loose bridge pins

[Tom Driscoll]

-----Original Message-----
From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On
Behalf Of Paul Tizzard
Sent: Monday, February 03, 2003 2:45 AM
To: Pianotech
Subject: Detuning bass strings was Re: loose bridge pins

Hi, 

A couple of weeks ago someone asked if they could detune just the bass
strings, to work on the bass bridge, without damaging the frame. I was
surprised to read that one can! I have always been led to believe that
you have to detune the piano in a specific way eg. all A's, A#'s etc. I
see that Ron Nossaman has again ok'd the procedure, so I wasn't seeing
things. How is it that structurally the frame is able to withstand the
release of tension in the bass area? Is it related to the findings of Al
Sanderson, that the plate is "loaded up more equally" when pitch raising
starting on A1 and going up chromatically?
Thanks,

Paul Tizzard
S. Africa

Pal,
	 The structural survival of the plate does not  require the
tension of the bass strings . I'm not a structural engineer ,but it was
explained to me that piano plate design has a saftey factor far
exceeding any imbalance as you describe. 
	Tom Driscoll