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I'm rebuilding a Julius Bauer grand that has an odd characteristic I've seen only a few times in 40 years of rebuilding: The ribs are glued to the top of the soundboard, instead of the normal glued-to-the-underside configuration. I wondered if anyone knew some history about which piano makers first invented/used this top-rib configuration, and what they thought was the advantage gained. Obviously, any advantage must have been insignificant, as no modern pianos continued the practice, and at first glance, it seems to be counterproductive to the concept of holding the soundboard in its upwards crowned shape. Anybody know the history & purpose of this top-rib experiment?

The only one like it that I've encountered was an A.B. Chase grand.

I would really love to see some pictures. Is that possible?

I have a 1887 Steinway A that has ribs on the top - I presume these were added at some point when it was restored.

I'll see if I can dig out some photos tomorrow.

[edit] There are also ribs on the underside

Paul.

The Julius Bauer has ribs on both the top and bottom of the soundboard. I rebuilt one about 15 years ago. Nice solid piano

Yeah, Julius Bauer - full perimeter plate and I believe the board and pin block comes out with the plate as one unit if I'm not mistaken???
Only ever seen a few of these.

I don’t know the full history of the design. The earliest reference I’ve seen is an 1885 patent (US 320264 A) issued to John R. Lomas (with half being assigned to B. Shoninger). This patent very simply describes a soundboard assembly with superimposed ribs on both sides of the soundboard panel just as was later used by Bauer.

I’ve only seen this soundboard design used on Julius Bauer pianos. No modification of this patent was ever issued to [William M.] Bauer for the invention so I assume JB used it as described. It seems to be used in the 1914 patent (US 1171921 A) issued to Bauer for his string frame and adjustable bearing mechanism although Bauer makes no special claims for the soundboard in this patent. Both grand and vertical JB pianos used the feature.

I owned a 9’ JB grand with all of their bells and whistles for a while. Fascinating instrument. Heaviest 9’ piano I’ve ever seen—David Rubenstein’s 12’ piano is heavier but not by much.

The (claimed) advantages were crown stability and lighter weight. For a given amount of overall soundboard stiffness the combined weight of the two superimposed ribs could somewhat less than that of a traditional single ribs used in conventional soundboard design.

Essentially this systems acts like a three-ply laminate with the crown being formed during the press cycle. Compared to conventional soundboard systems the crown in these systems was absolutely stable. I monitored string bearing on my piano in Sacramento, California (hot and dry in the summer) and in Jonesboro, Arkansas (hot and humid in the summer and cold and humid in the winter). I don’t recall it ever changing. If it had it would have given me an excuse to play around with the crown-adjusting mechanism built into the piano.

ddf

Thanks Del, that's great info.Two other questions arise from your response:

- What made the Bauer grand the heaviest ever? More wood beams? Different plate design? In an old Bauer promotional catalogue, they bragged that its structure was so much more stable that they actually needed less beams and less square inches of plate w/more open spaces.You'd think it would end up being lighter.

- What, and where, is this crown-adjusting mechanism you speak of? Was it only on 7' or 9' models. The one I'm rebuilding is a 6 footer.

As for sandwiching the board between top & bottom ribs, my customer actually asked a smart question which was, wouldn't that be somewhat more restrictive to the free-floating vibrations of the soundboard, compared to boards with ribs on bottom only? Wouldn't it kind of clamp down and make for a thinner resonance?

My piano had no bellybracing at all. The weight was primarily in the string frame. It had the most complex and massive casting I’ve ever seen in a piano. Grand or vertical.


[quote}— What, and where, is this crown-adjusting mechanism you speak of? Was it only on 7' or 9' models. The one I'm rebuilding is a 6 footer. [/quote]
Look up the patent (just do a Google patent search). The patent drawings explain it better than I could.



Not really. It’s the overall stiffness of the system that we’re interested in. I made no effort to measure this in my piano but I did note that the ribs—combined—were about half that of a normal rib. I.e., each rib was probably one-fourth the height of a typical rib in a conventional soundboard system. My 9’ JB was a very nice sounding piano.

I’d leave the soundboard alone. Clean it up and, if the finish has deteriorated, you might consider refinishing it. But it’s highly unlikely that—unless the ribs are delaminating from the panel or something—it will need anything more than this.

I rebuilt my piano in the early 1980s and sold it shortly thereafter. Were I doing the job today I’d do more measuring and testing. It was one of the most interesting pianos I’ve ever owned.

ddf

Bis repetita, please!

Again thanks for great info Del. Olek & A443 want photos. Don't know if you have any from your old 9' you can post. I'll post some of the 6-footer I'm rebuilding later this week, it's being moved into my shop on Friday.

Del,

I have an Upright (about 55") Bauer here in the Sacramento area built like this. Had to move it out from the wall an inch. Not easy. Haven't tuned it for years though.

Here's the picture of my 1887 Steinway A - the small ribs can be seen near the case in the centre of the picture. The ribs under the soundboard appear to be of "normal" dimensions and shape.



Paul.

Hey Paul, not seeing any photo or attachment to your post?

(Hmmm, and if you took an old upright that had little crown and put some shaped ribs on the FRONT side, after increasing the crown by using wedges between the posts and the ribs on the BACK side...)

Just thinking out loud, no need for anyone to respond.

Hmm, it was there .... try this
Paul

That 1882 Julius Bauer with the top-mounted soundboard ribs arrived at my shop. Here's a first photo, prior to any disassembly.

The thought that kept coming to me as I worked on my 9' JB went something along the lines of, "I'd sure like to have seen the look on the pattern maker's and foundrymen's faces when they first saw the design of that string frame." In mine, if memory serves, it was a two-part casting.

ddf

Is there any appreciable addition to resonance at any point of the scale with such an open casting as this? Or any color the top ribs contributes?

Who knows? The JB pianos had so many unique features it would be impossible to sort out which tonal characteristic was attributable to which design or manufacturing feature.

What I do know is that a professional jazz pianist fell in love with the thing the first time she played it and couldn't rest until she had raised the money to buy it.

ddf