A New Blower for Op. 1458
The Inaugural concert in February '08 for Aeolian Pipe Organ Opus 1458 was always going to be a close run thing, with the possibility of any number of “teething problems” marring the music, but as it happened very few issues arose,
the one very odd cypher (a ventil wire making intermittent contact with pedal note no. 3 on the bourdon ) kept off for almost the entire event, and only became ugly during the final stages of a very long day, and after much refreshment had been consumed. A bigger problem, which almost prevented the whole thing was the lack of blower.
How many blowers have I been offered
when I did not need one? And at the stage where one was
essential, where were they all? Such is life. At the last
moment a 1 ½ horse-power “Discus”
machine was found, completely stripped down,
repainted, and the three phase motor adapted to run on house
mains. This gave a pretty good supply of wind at around 7”
water gauge-ideal for the main organ, but inadequate for the
8” solo division. This blower certainly got me out of a jam,
and so long as anything approaching full organ was not needed
it was fine. With the inauguration well over, and many other
issues dealt with my thoughts turned again to the wind supply.
Old Discus Blower restoration
Old Discus Blower before reassembly
Old Discus blower being installed
About a year ago, I had become acquainted with the rusty
remains of a large blowing plant in a church in Torquay, which
was surplus to requirements. It was a monster, and seemingly
in desperate need of a new, and better home. At the time the
seemingly impossible size and weight of the thing intimidated
me, additionally it seemed as if the church had been built
around it, so small were the access doors. Then, one day I
just woke up early with the clear conviction in my head that I
needed a new blower, and this old machine was going to be it!
Adrian Tuddenham, of “Poppy Records”
in Bath, happened to be in the area, and having confirmed that this old wreck was still where I
last saw it, and that it was more than available (“can you
please shift it for us?”) we decided to go down to reconnoitre. In
the mean time I had gone back to look at some photos that
I had taken last time, and “you know” I said to myself, “it's
not that big really”. Well, we got to the church, and how wrong
I was! As we descended into the vault, which had at
one time also housed a Gentlemans toilet, it seemed to have grown, as if,
nourished by the damp lavatorial air, like a giant rusty
cylindrical mushroom, it was ready to burst. How on earth were
we going to shift it?
The 'New' Blower as found.
Starter and Isolator.
Disassembly in progress.
I had chatted to Mr. Fothergill, of B.O.B. Organ blowers of
Wareham in Dorset, and he had assured me that it would “all
break down” quite nicely, and so we tried one of the great
nuts on the end of the studding holding the whole job
together. To my surprise, it was easily moved and, in fact
nearly all of the nuts, bolts screws and flanges that we tried
were easily removable. It was if this sleeping giant saw the
opportunity of release from its grimy dungeon and was doing
all in its considerable power to make things easy for us-or am
I being sentimental?
After the end of a long afternoon and evening, what had
intended to be an exploratory session turned out to be the
means by which we had the job of disassembly half done. Adrian
made very careful notes of the “very Victorian looking”
starting gear which I had assumed would have to be scrapped,
but which he assured me would be possible to fix up again, and
we worked on happily, quite oblivious of the darkness, the
damp and, much of the time, the low ceiling of our work site.
At about 9.00 a meal at the local Wetherspoon's was
definitely called for, and clutching the “Rockingham” name
plate that I had discovered, and unscrewed first of all, we
sat down to enjoy our food, being conspicuously the dirtiest
people in the establishment.
The following day, back we went, and breaking into the drum
of the blower were surprised to find a lot of cork sheet, and
great wooden discs, like the top of beer barrels. The
impellers were almost invisible at this stage, and also in
evidence were sheets of tin plate like the leaves of some
weird plant. These were the wind deflectors. The whole drum
was bounded by long strips of spring steel. It was a curious
device, and one that I was keen to learn about. I think
Rockingham's were some of the earliest manufactures of this
sort of centrifugal blowing machine, and no doubt that in
decades following the making of this one, improvements were
made, allowing the size to be reduced, and methods of
construction simplified, but as we got deeper into the rusty
old hulk of the once proud machine I was filled with respect
for the sheer scale and ingenuity of it all: the bearings, and
the special arrangements for their lubrication, the accuracy
of a ground frame that barely needed the universal joint
between motor and blower, so accurately was it made, and the
monster 5 HP Century motor that crouched at one end, defying
us to remove it.
Inside the Blower showing Wooden Disks and Cork.
Parts lined up outside the Church.
At the end of the second day in Torquay (the first full
day) the job was done, and the immense Rockingham equipment
broken down into 5 massive cast iron discs or plates, a neat
stack of R.S.J.s and those curious wooden discs, attendant
studding, and simply dozens of large old nuts. On the journey
home I was wondering what I had done! What if it didn't
work, how I was going to accommodate it if it did! Almost
immediately after an improvised supper, Adrian set to work,
and the results of the evening's labours surprised both of us
The old motor had had a traumatic last few years of its
life, culminating in the commutator getting so hot that in its
final efforts to drive the blower, it had literally flung off
most of the solder connecting the armature windings to it
rather like a molten metal version of a garden sprinkler.
Perhaps it managed to limp on for a while, or perhaps it was
condemned there and then by electricians who may well not have
been organ enthusiasts. The cause of the great heat? Probably
due to the fact that the brushes (used to start this type of
induction motor, and run it up to synchronous speed prior to
flying off) had remained in contact with the commutator,
grinding away until one day during an extended run, it just
critically over heated. Anyone in the vicinity would have
heard the motor screaming away - but that was the point - it
was buried under the back of the church where no one would
have been aware of its plight. And so it was all left to
rust-that is until after supper on the evening of the 30th.
Try as we might to wait until the morning, we both wanted
to see what could be done with the motor, and Adrian was able
to confirm that despite the damage, there was no real reason
why it would not work, and so we had a go. After checking for
shorted windings, frozen bearings and anything else suspicious
Adrian cautiously offered it 55 volts and the motor stirred
into action with a shower of sparks and a noise like a washing
machine full of gravel. After checking that the sparks, and
other incandescent debris had not caught the carpet on fire,
Adrian cautiously moved to 110 volts. The rattling and
sparking seemed to spell disaster, and I began to give up hope
of using this grand old relic of the 1920s as a means of power
- but Adrian seemed to think that all was normal for this
stage in the proceedings. It was quite late now, but we had
got so far, that we just had to carry on. What would be the
effect of 240 v? I hardly dared wonder.
To carry on, without blowing fuses, we would need to use
the starter. This was an excellent unit looking like an
elongated lavatory cistern. It was cast iron, and very
Victorian. Its function was to remove fairly large
resistances, one by one (six in all) as the motor came up to
speed. It did this, when installed, by moving pneumatically a
pair of brushes over the terminals of these resistances in
response to blower pressure. Adrian set it up with some wire
that was handy, and contrived a means of operating the starter
manually. I held my breath, also a video camera, and Adrian
switched on. The noise was terrific, and then, sounding like a
jet engine as the starter was pushed, I was convinced that the
motor would just burn out. At full voltage it was screaming
like a racing car, and after a few seconds we switched off. I
could not imagine how this motor could ever be used again.
What I did not realise was that the motor had failed to start
properly, and was running on its brushes at a speed well in
excess of what it was designed to do. Removing the armature (a
two-man lift) revealed that there was a lot of corrosion
inside, where I now understand that the mechanism for
transmitting the motion of the flying weights resides. The
bell cranks, and push rod assembly was well rusted, but could
be made to work stiffly with some lubrication and a bit of
brute force to get it going.
We re-assembled the motor, and again I held my breath.
Again the rattling and sparking started, then the high pitched
roar as 1460 r.p.m. was reached and then..........I thought
Adrian had disconnected it all. Almost silence. No more
sparks. Far from having been disconnected, however, the motor
had reached sufficient speed, the weights had flown out, the
brushes pushed back, and the shorting ring thrown against the
commutator and once again, quite simply, it was doing what it
was designed to do. Considering that the motor had almost
certainly been heading for the scrap heap - helped on its way
by a sledge hammer no doubt, our long day of toil, and the
lateness of the hour, I think I can be forgiven for being
quite moved by it all.
Suddenly I noticed that what I thought would have been an
enormous problem had virtually solved itself. Very heavy-duty
cables had been used to supply this motor in its previous
location, and I had visions of the huge currents required to
start and run it, and all the problems that would be caused.
But the motor was running now on something a little bigger
than bell wire, and had not blown a 13 amp fuse upon several
starts. The problem simply did not exist!! Then another
thought struck me and for the first time I began to realise
what it all meant. I had seen a Century motor, like this one,
before. It was on Howard Towlson's Aeolian organ in Syracuse,
and I think this brand were invariably used on the Spencer
“Orgoblow” blowers that a lot of Aeolians were equipped with.
Mine certainly was-I have the details, and upon checking, it
was also 5 horse power! In effect I now had a blower of
identical power, and similar vintage to what was originally
supplied when my organ was new in 1919. The two old timers had
found each other!
Armature showing Shorting Ring.
Repairs to the Commutator.
Facing off the Commutator.
In just under a week Adrian came back for the task of
reassembling the whole blower, and in the mean-time I had done
very little else but restore and re-paint the various
components. Part of the take-off spout needed quite a bit of
filling, because of corrosion damage, and the new “pill-box”
pneumatic motor for the starter was quite a challenge to make
and fit, but by the time we met again, everything was ready
for the big day. Actually, it took two days – but from when we
started the disassembly to when we were ready to switch on had
taken us 14 days. Quite an achievement I think.
New pneumatic motor for the starter.
Motor and Starter - bench test.
Assembling the Rockingham blower was hard work, but
rewarding almost immediately. My video and digital images of
the disassembly had been very useful, and Adrian's cool head
and knowledge of engineering invaluable. New cork sheet for
the sound deadening layer underneath the steel bands was
purchased locally, new ¼ “ whitworth bolts, wire mesh and
cable was brought up from Bath, and when all the proper
electrical safety issues had been addressed, it was time to
switch on. True, there were still problems with the brushes
being thrown off, now the motor had its load, but these were
subsequently solved when Adrian lessened the tension of the
large coil spring that kept the flying weights in place during
start up. It rather looked as if this spring was in fact a
replacement of slightly too strong a grade – another mystery
partially solved. True, also it seemed certain that the
commutator would need to be skimmed in order to work more
quietly, but within the space of a couple of weeks I had the
blower of my dreams!
Some of the cast iron discs awaiting reassembly.
Part way through reassembly.
The Finished Job.
© Paul Morris 2009