site navigation

The Fred J. Cooper Memorial Organ
Verizon Hall
Kimmel Center for the Performing Arts
Philadelphia, Pennsylvania

Opus 76

Phase 2 Construction

Construction of the Verizon Hall organ began in earnest in our shop in April 2004 and continued until July 2005. The photos below highlight some parts of this process. There is a separate page devoted to the consoles.


Some of the reservoirs under construction. Most are 42" x 78".

A partial view of the stack of twelve reservoirs behind the organ. A combination of weights and springs is used for most reservoirs.

Gerrid (left) and Lyndon (right) work on windchests for the organ. The windchest in the foreground is for one third of the Great; the space in the middle running side-to-side is for a walkboard.

Gerrid cleans up the Positive slider windchests, which are lying sans toeboards upside down on carts.

Construction of some of the many wood pipes in the organ.

A stack of swell shades waiting to be cut to the proper length. The disassembled parts of a swell shade frame are lying on the sawhorses.

The swell shutter front for the Solo division.

Randy Hausman assembling the Swell expression box, whose interior height is almost 14' tall. The square hole in the shade front frame is to allow a steel I-beam to pass through.

Bill Ayers voicing the Great 16' Posaune.

The Positive expression box, a mirror image of the Swell.

A view inside the Positive box. Some of the toeboards are in place over the sliders; the slider motors are in the foreground.

Meridith Sperling racks the Positive Salicional 8'.

Art Middleton and the completed Pedal square board. Located behind the console (which would be on the left in this view), it divides the Pedal trackers into CC and C# sides.

Donny working on the 32' Contre Bombarde resonators.

A number of glued-up resonators, the longest of which is 32' G#. There is an entire octave of pipes longer than these (32' G to 64' A).

Art fits tapered shallots of the Contre Bombarde to the wooden blocks. The shallot for 64' AAAAA is in the left foreground.

A shallot in its boot: this is 32' CCCC#.

Meridith and Randy stand next to the pipes of the Contre Bombarde 32', which extends into the 64' octave. In this view, the upper halves of 64' A# and 32' C have not been set up, because they are too tall for the erecting room.

The Great and Pedal treble slider windchests are set on their steel frames. The 22-stop Great occupies the center in three chests, while the 6-stop Pedal is divided in transverse CC and C# halves on either side. To give a sense of scale: the entire assembly is about 8' wide by 25' long.

Meridith racks some of the larger bass pipes on the Great.

• • •

The Aeoline 16', A Free Reed Stop

The Positive division of the Verizon Hall organ contains an Aeoline 16', which is inspired by the free reed voices of 19th century German organ builder Friedrich Ladegast. Unlike most reed stops, in which a brass tongue strikes the face of a shallot, free reed tongues swing through an opening in the shallot, much like harmonium reeds.

The Verizon Hall Aeoline was made by Carl Giesecke & Sohn of Göttingen, Germany. In July 2005 Angelika Hesse, Giesecke’s technical director, and Wolfgang Born, a Giesecke reed voicer, visited our shop to collaborate in the voicing of this stop.

Wolfgang explains some principles of operation for free reed pipes as Bill and John look on.

Bill files a tongue with a suggestion from Wolfgang.

The upper part of the tongue is scraped to make it thinner, thus lowering the pitch.

The participants: Wolfgang Born, John Ourensma, Angelika Hesse, Bill Ayers, and John Panning, with the Aeoline 16' as backdrop.

Op. 76 Home

Phase 1 InstallationKimmel Center Dedication
Phase 2 ConstructionPhase 2 InstallationConsoles
Organ DedicationDedication Reviews


Our ShopInstrumentsRecordingsTestimonials
Sound SamplesRecitalsNews ArchiveHome

Dobson Pipe Organ Builders, Ltd.
200 North Illinois Street • Post Office Box 25
Lake City, Iowa 51449 USA
+1 712 464 8065

Site conception by metaglyph

All contents ©1999–2016 Dobson Pipe Organ Builders, Ltd.