Just when you think that you are getting the hang of things, something
new pops up.

I have just carried out repairs to a Steinway Upright with Themodist
expression.  The impressive thing about it is the scale.  All of the
speaking pneumatics are slightly larger than usual.

The sustain pneumatic is particularly substantial.  This consists of
a fairly square (8" x 6") pneumatic with sustain rod activating lever
attached on top, mounted above a spring tensioned pneumatic similar to
that used in the main governor.  The latter is about 7" x 4.5" and is
upside-down and back-to-front in relation to the top pneumatic.  The
whole unit is supported by four 9" legs and supplied by two inputs.

The suction is serious stuff: a 1.25" pipe direct from the main
governor.  The signal pipe is 0.2" and was connected in such a way as
to carry suction rather than atmosphere.  This of course may be wrong.

This is where I have a problem.  Even testing with atmosphere does not
activate the top pneumatic.  The repairs that I carried out were simply
to replace the covering cloths.  The valve inside the lower pneumatic
seems in good condition, and comprises a large pouch with a large
inside valve on a wire stem.  The sustain selector lever in the
spoolbox is connected to a sliding plate which opens/closes two
separate inlets rather than just one.

The Themodist selector operates on a similar principle, and the two
features appear to be interconnected via a distribution box.  I
diagrammed everything prior to starting work and know that I have
re-connected all tubing as before.

My questions are these:

1.  Does anyone have a tubing diagram for this Steinway Themodist
arrangement?

2.  Should the sustain pneumatic signal pipe carry suction or
atmosphere?  Or even both, depending upon other operating conditions?

3.  What is likely to be the reason for non-operation?

All replies gratefully acknowledged.

Roger Waring