One pass Large Pitch Raises Safe?

[Paul Chick (Earthlink)]

Subject: One pass Large Pitch Raises Safe?


I've been following a discussion regarding a large pitch-raise of 100 cents
or more being done in one pass.  Is this safe?  Do you run the risk of
damaging a plate by, say, concentrating tension in one area as you begin to
pull the pitch up.  I'm not talking about strings which are risky in their
own way.  I've understood that when there is such a large tension
adjustment to be made that it is safer to spread it out as octaves, such as
all the A's then all of the E's then all of the C's, then fill in the rest
after which you do a fine tune.  Am I being overly cautious?

Andrew

When we restring a grand, we pull the strings up from almost nothing to a
4th below pitch A440, then we pull them up a 3rd below pitch, then one step,
then 1/2 step, then over by about 6 beats (at A440).  All the center strings
get it first at each pitch, then the left side of the unisons, from the
treble to the break, followed by all the right sides fro mthe break up to
C8. The wound unisons are tuned last from the break down.  It takes us about
15-20 minutes per pitch.  I watched the chip tuners at the Kimball plant
pull the strung backs from zero to pitch in one pass starting at A0.  If
something broke, it went on a "side track" for repair.  No one could
remember the last time a plate failed.  We have pulled pianos up 100 cents
in one pass with this method with no problems.

Paul C