Bridge design

[Erwinspiano@AOL.COM]

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In a message dated 7/6/2002 3:13:43 AM Pacific Daylight Time, 
mfarrel2@tampabay.rr.com writes:


> Subj:Re: Bridge design 
> Date:7/6/2002 3:13:43 AM Pacific Daylight Time
> From:<A HREF="mailto:mfarrel2@tampabay.rr.com">mfarrel2@tampabay.rr.com</A>
> Reply-to:<A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A>
> To:<A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A>
> Sent from the Internet 
> 
> 
> 
> I have two 1912 or so Mason & Hamlin uprights with the shortened agraffe 
> area (although not agraffes on the upright), but they both have the low 
> tenor transition bridge rather than a shortened/curved/whatevered low end 
> of the tenor bridge. I wonder why they did not use the transition bridge on 
> the grand? What length is the A?
> 
> Terry Farrell
>   
        Terry
 I don't know why they didn't use it. Probably some of the design folks liked 
it and some didn't. Or cost factors and simplified production issues.
               The Mason & Hamlin A is 5 ft. 8 inch but because of its case 
width the board has more square inches than the Stwy L or O. Hence its rather 
large sound for its size. 
   I also purchased recently 2 Mason & Hamlin AA 6 ft. 3 inch from 1950. The 
company did away with the old third bridge  as on the old  model Mason Double 
As and this one has, I think 5 bi-chords, on the long bridge much like the 
long Stwy A which is 6 ft. 4 inch. The break is quite acceptable. The bridge 
is not under cut.
   Back to the Stwy Ms under cut bridge in the low tenor. If it was for mass 
reduction or flexiblity why then did they put the same amout of mass back 
under the bridge in the form of a large dowell and wooden nut negating the 
bridge mass reduction idea? I dunno either. the Stwy M isn't the only model 
or brand to employ this either. I personally don't put the nuts and dowells 
back on any more unless requested for originality  Issues by techs.
   Dale Erwin

> .
> .
> > >> On a Steinway M there are several gaps between the bridge and the 
> > >> soundboard at the lower end of the treble/tenor bridge.  What is the 
> > >> purpose of those gaps in design, and if one were remaking a bridge for 
> 
> > >> that instrument, would you duplicate that design?
> > >>  
> > >> David Love
> > 
> > 
> > >  David, Del
> > >   I've often wondered the same thing about the M bridge. A while back I 
> 
> > > think we talked about floating sound boards and bridge modifications in 
> 
> > > this area as well.
> > >   Oddly enough I just purchased 2 Mason As . One from 1929 and the 
> other 
> > > 1931. Thw 1929 has the usual long tenor bridge and the other has a 
> modified 
> > > tenor bridge. The bridge makes an abrupt swing towards the staight 
> /bass 
> > > side of the case. This shortens up the speaking length bout 3 or 4 
> inches 
> > > and on it are of course 5 wrapped bi-chord unisons. The plate area at 
> the 
> > > agraffes is also shortened appox. an inch. 
> > >   I found this to have a very good bass tenor break and a step in the 
> right 
> > > direction with this model considering the break with plain wire has 
> been 
> > > changed i different wire size configurations over time. And with not 
> much 
> > > success. To bad that Mason& Hamlin didn't stick with it. No doubt more 
> > > costly .SO WHAT. Any rebuilder could easily duplicate this modification 
> 
> > > except the agraffe change.
> > >   What say ye.
> > >   >>>>Dale Erwin>>>
> > 
> >        
> > 
> > > A better solution would be to straighten out the scaling in that area 
> and 
> > > use an extension on the end of the tenor bridge to stiffen up the end 
> of 
> > > the bridge -- even better, design in a transition bridge -- and/or 
> redesign 
> > > the ribbing, and leave out the gaps. 
> > >  
> > > Del
> > > 
> > 


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