In the shop currently is a full-size Steinway upright Duo-Art with an
uncertain pedigree.  The serial number, 171xxx, dates it to 1915.  This
is the third Duo-Art upright to come through the shop recently.  The
first was a Weber from 1919, with a steamboat pump, five-position
"modify" switch and an expression box with a pneumatic that operates
a flat metal "bail" that limits the downward travel of the regulators
in one of the modify switch positions.  The 88-note stack had three
tiers of striker pneumatics with cross valves.  Fortunately, the pump's
pulleys were machined cast iron, not pot metal.  Refurbishment was
straightforward.

Next came a Stroud that dated to 1929, with an 88-note, two-tier stack
and a 17" box pump.  Surprisingly, this turned out to be a better
sounding piano than the Weber.

Now comes the Steinway.  I didn't inspect it very closely when it first
came in, which turned out to be a mistake.  What I first noticed was
that almost all of the hoses and tubing had been replaced with clear
plastic, probably "Tygon", which I proceeded to rip out with great
gusto.  Having finished with that, I took a closer look at what was
there and started scratching my head.

The first thing I see is the original steamboat pump has been replaced
with a 15" box pump.  Half of the original motor mounting apparatus
(two vertical pins on the treble lower case shoulder) were still in
position, and the bottom board and front lower rail had the "cuts" for
the pump pulley clearance.  From here it starts to get a little weird.

Next up, I look at the key slip controls.  It has the typical (for that
vintage) "Temponamic" knob for manual control of the Accompaniment
level, on the treble side.  On the bass side are the manual Theme level
lever and application thumb buttons, oriented vertically.  These look
typical except there are no labels to indicate their function, not even
any screw or brad holes in the wood where any would have been mounted.
More unusual is that these are the only controls on the bass side,
there is no Modify switch!  Things are starting to get interesting.

Next oddity are the spool box switches.  There is a Duo-Art "Off-On"
switch _without_ an "arrow" mid-setting and a "Sustain Pedal" Off-On
switch, unknown to me in any true Duo-Art configuration.  But here's
the real kicker: there is _no_ Rewind pneumatic!  It's not just missing,
it appears there never was one installed.  There are no suspect empty
screw holes and no evidence anywhere along the shift linkage that a
pneumatic would have engaged it.

The customer has no information about its origin or maintenance or
restoration history, so now I'm playing amateur detective.  Here are
some other details I find:

A. The air motor pneumatic sections are larger than the cloth pattern
I have for them which have worked for every other Duo-Art/Aeolian air
motor I have ever recovered.

B. The take-up spool is shiny (nickel?) plated rather than black wood.
There is no "Re-play" hole, which is not surprising since there is no
Re-play Off-On switch or Rewind/Re-play pneumatic.

C. There _is_ a switch cut-off pneumatic that apparently takes its
signal only from the motor cut-off tracker bar hole.

D. The tracking ears are mounted "upside-down", with the "body" above
the tracker bar and the "ears" below.

E. There are two eight channel cut-outs for the accordion signals and
unused (in Duo-Art mode) notes.

F. The tracking pneumatic is _very_ long (about 8 inches) and does not
have a signal cut-out for Rewind.

G. The nipple of the tracker bar Rewind hole shows evidence of having
had a plastic tube attached, but where it went is a mystery, since
there is no Rewind pneumatic, and I did not trace it as I was
de-tubing.

H. The expression box appears to be of a later upright design, without
the components of the apparently later (1919) Weber box mentioned
above.  It is unremarkable in other respects, except for a two-port
pallet valve attached to the upper bass rear of the box, positioned
such that, as the Accompaniment accordion collapses, the movement of
a lever extension operating the bass-side spill valve closing arm
approaches the actuation point of the pallet valve, presumably to open
it when the accordion reaches its maximum excursion.

Interestingly, the adjustment of the various linkages, as found, is
such that the pallet valve would never have actually opened, even
though that seems to be the design.  The two nipples of the valve also
show evidence of having had the plastic tubes attached, but again,
I did not trace them while de-tubing, so where they went is unknown.

The only logical place would be the two Theme application primary
valves, but this makes no sense from an expression viewpoint, since if
Accompaniment level is at maximum, the Theme level could only be equal
to or less than Accompaniment, so what's the point of applying both
themes?  Certainly, this would not have had a "crash valve" effect as
intended in grand expression boxes.

The only reference for this component I can find in the MMD Archives is
a post by Eric Shoemaker in Washington State in 2003 who had a similar,
if not identical set-up:

  http://www.mmdigest.com/Archives/Digests/200308/2003.08.12.11.html 

It was on a 1917 piano, but he did not specify the brand.  I could find
no responses to his posting, and an inquiry to the only email address
I could find for him to see if he ever determined the purpose of the
valve, bounced.  Eric's most recent MMD posting was in 2010; does anyone
have current contact information for him?

I. The "medium weight" cloth on various pneumatics (air motor,
expression regulators, pedal pneumatics, tracker, etc.) appears to be
the original, greenish tan/beige color and is extremely dry-rotted.
In contrast, the striker pneumatic cloth is that "immortal" Aeolian
cloth from that vintage that is still smooth, supple, and shows no
evidence of aging or pin-holing.

J. The piano's "soft" pedal pneumatic has a single port pallet valve
that opens when the pneumatic is fully collapsed.  This is more typical
of "half Duo-Art" actions of similar vintage, and was most likely
connected to operate the #2 Accompaniment accordion section.

K. The keybed hole for the bass stack supply hose is 2" in diameter,
while the one for the treble supply hose is 1-1/2-inch in diameter.
Typically, these are the same size in Duo-Art installations.

L. The shift lever is labeled "Rewind - Silent - Normal", not
"Rewind - Silent - Play".  This configuration is mentioned in at
least one Archives article on Themodist topics:

  http://www.mmdigest.com/Archives/Digests/200606/2006.06.07.03.html 

So, what's the story on this piano?  If it was originally a
non-expression, 88-note Aeolian action, it would have presumably been
foot-pumped, however there is no pedal cut-out door in the bottom
board, and no tell-tale screw holes where the treadle "trapeze"
mechanism would have been mounted.  I have not yet disassembled the
three-tier, 88-note cross valve stack, but I expect to find a "factory"
divided stack, i.e., not an "after-market" upgrade from a single
chamber 88-note stack.

Could it have been a Themodist mechanism that was "upgraded" to full
Duo-Art, and if so, by whom? I have little experience with Themodist,
but from what I can glean from the Archives, they were usually, if not
always foot-pumped.  Also mitigating against this theory is that the
Themodist expression boxes I _have_ seen have mounting hole patterns
that don't match the screw holes that are there for the true Duo-Art
box, and there are no "extra" holes.  If this had been a "factory"
upgrade, I would have expected them to put in a 17" pump, for which
there was plenty of vertical room (23") instead of the 15" pump.

The last possibility is that this was a full-up Duo-Art from the
beginning, with an upgrade at some point from steamboat pump to 15" box
pump, but the lack of a modify switch and a rewind pneumatic makes this
unlikely.

During this rebuild, I feel it will be necessary (for operator
convenience if nothing else), to install, at least, a rewind actuator,
and I should have plenty of stuff in the "boneyard" to accomplish this.
Its absence, especially if this was a full-up Duo-Art, is truly
puzzling.

Anyone care to put forth any theories?

John Grant

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