All the 69 pipes in this organ were made by
myself. Shown here is the smallest of the main melody bourdon pipes - top "C"
(transposed up 3 notes = D# - MIDI 75). A 50-pence coin is shown for size comparison (approx.
27mm across). The pipe body is 109mm long and the cross-section is approx. 17mm square. Its
internal cross-section (the important bit) is a mere 8mm square. The stopper is shown before
fitting. Allowance had been made for its leather plug, shown by the coin. At the other end of
the pipe (out of view) is the foot, made as a separate piece on an engineer's lathe - a
wood-turning lathe would not be accurate enough.
Pipe scaling was accomplished using my scale chart on an Excel spreadsheet. I programmed the
original many years ago on a Casio pocket computer, now donated to the National Computer Museum
in Bletchley. The scale progression from the largest to the smallest pipe is approximately
half-size every 16 notes for the width and half-size every 12 notes for length. Every pipe has
unique dimensions (paired for the two ranks of bourdons).
Here, I will show how a rank of pipes is made, using pictures of the smallest rank in
the organ - the mixture quint (actual pitch A# to A# - MIDI 82-94). Above left:
planks of suitable timber are quarter-sawn. Pine is used for backs and sides, maple for fronts.
The blocks are laminated from pine with a thin layer of maple at the front - wood forming the
wind-way must be something hard to minimize erosion from dusty air being blown through.
The planks are cut down to relevant dimensions for the pipes, with final
planing allowance. The narrow ones on the left are the sides, the long wide ones on the right
are the backs, and the short wide ones are the fronts. The small pieces at top left are the
blocks - the tiny pieces with them are for spacing the open end of the pipes, to be sawn off
The sides are glued either side of the blocks, planed at front and
back and flue slots chiselled into the blocks. Above right:
The backs are glued into
position, and upper lips are chiselled onto the fronts.
Now the fronts are glued into position leaving pre-arranged spaces
that will become the mouth "cut-ups". You can see the extra length of the blocks
below the mouths. This area will be turned to a conical shape to produce integral feet. Some
historical organ restorations have revealed this kind of construction, so I decided to try it
on these tiny pipes. Above right:
This is the make-shift tool for turning the feet. It
is a small block of maple with a foot-taper bored into it. One corner of the block was cut away
to allow a chisel to be clamped into position. This contraption was mounted into the lathe
tailstock, and the pipes were fitted into a four-jaw chuck, and rotated by hand (power and
drive disconnected). It was time-consuming but successful.
This shows the pipe feet turned parallel. Just visible are the
centre points used for stabilizing the pipes at the tailstock end of the lathe. Above
One of the pipes after use of the taper tool. At the bottom of the picture is the
pipe's cap, showing the flue cut into it in the English style. All the flue pipes in the
organ have these "English" caps. Mechanical organs usually have their flues cut into
the blocks, but if cut too deep they are impossible to reduce. With this style, reduction is as
simple as planing off a little from the surface of the cap, or even making another cap - much
better than making another pipe.
The bass pipes, shown here, were mitred to
fit under the organ's floor. They are always best in that position so the case plays
its part in enhancing their resonance. These are the largest pipes in the organ, the longest
being 23 inches (583mm), there was not room enough for them to be left straight, but in any
case, their wind supply coming through a vertical transfer board running across the front of
the case dictated where the pipes' mouths needed to be.
The mitring process, done after voicing, is simple using a mitre saw fitted with a thin
blade, so not much length is lost. The only tricky part is where a mitre could interfere with
the stopper; the "C" pipe was close!
The "business" end of a reed pipe.
Fitted into the block with a semi-circuler wedge is the shallot - a brass tube open for its
length about one-fifth of its circumference, and fitted with an angled tip. Shallot-making is a
skilled job, and I leave it to the firm of W P Williams & Co, who have made all my shallots
(to my own specification) over the years. Across the gap is fitted a brass tongue which is very
slightly curved at the open end. The curve is hand-formed, itself an extremely skilled job,
especially considering all the pipes in a rank must have the same tone quality and power. The
slightest mis-curve or kink would completely spoil the result. I have always produced my own
tongues, for mechanical and church organs.
A bronze spring is pressed against the tongue limiting its free length. When wind is applied
to the space around this assembly (encased by a "boot") the tongue vibrates in
sympathy with its free length and the air column contained inside the resonator (not shown).
Tuning is achieved by moving the spring to shorten or lengthen the tongue's vibrating
The trumpet rank in bare wood. The largest four are made from
noticeably inferior timber, but that matters much less with reeds as the resonators only serve
to amplify the sound and stabilize the pitch. If knots in the wood are beginning to separate
they could be in danger of falling out in time. In that case a patch of thin leather can be
glued over them on the inside. Above right:
The trumpets, now finished. The boots
(plastic tube covered with brown paper) are fitted to the resonators with tapered wood
"feet" similar to the feet made for flue pipes. The boots, in turn, are fitted with
shaped wood tubes for wind entry. Six of the pipes get their wind from the top of the
distribution board, and the other three get it from the front. The tops of the boots are sealed
with leather patches to contain the wind and dampen any internal resonance which could spoil
the speech. At the bottom can be seen captive nuts used with bolts for supporting the
resonators at the open ends. The pipes speak through the opening at the bottom the façade, with
their tone quality strongly influenced by the space below the organ's floor. This tone is
augmented by a rank of "helpers" mounted between the bass pipes under the floor,
speaking an octave higher than the reeds.