What Is a Pallet in a Pipe Organ?

A pallet is the movable part of a windchest that opens or closes the hole through which wind reaches a pipe or a group of pipes. That is the definition in the Organ Historical Society’s glossary, and it is deliberately broad: the glossary allows that the holes a pallet controls lead to pipes eventually and in some cases by further passages, because the opening under a pallet often feeds a channel rather than a single pipe toe. The job is the same either way. Below the pallet is the pallet box, holding pressurized wind admitted from a reservoir or a Schwimmer. Above it is a channel connected to pipes. While the pallet stays closed, the wind stays in the box; when the pallet is pulled open, wind crosses into the channel and the pipes on that channel can speak.

The word matters because it names one specific role. In a common arrangement a windchest is a wind-distribution and control point beneath the pipes, and it contains valves and selection devices that together govern when pressurized air can enter a pipe. The pallet is the valve in that pairing, the part that responds to the key. Whether a given pipe then sounds also depends on the selection device, which is a slider in one family and a pitman in another, and those selection devices are not pallets.

In a pallet-and-slider chest the pallet sits at the bottom, inside the pallet box, with one pallet for each note. James H. Cook’s 1998 tutorial for the Organ Historical Society describes this chest as three sections stacked on one another, each with a different purpose. The pallet box runs along the bottom and receives wind from a reservoir or a Schwimmer. Immediately above it are the key channels, which run perpendicular to the pallet box, are separate from one another, and each connect to the pallet box only through the opening its own pallet controls.

On top sits the section made up of the topboard, the sliders, and the toeboards on which the pipes stand; the toeboard is drilled with holes so that wind from the chest can enter the pipes, whose toe holes are aligned to those openings by the racks that support them.

Every pipe standing over one note, whatever stop it belongs to, draws from that note’s single pallet and common key channel. Goulding and Wood’s account of the slider chest gives this as the reason every stop drawn on a note speaks together and with the same attack. It also fixes the pallet’s place in the two-condition rule of this chest family: a pipe speaks only when a pallet opens under the key and a slider has been aligned by the stop control. The pallet supplies the first condition and has no part in the second. How the sliders do their half of the work, and what the whole operating sequence looks like, is developed on the slider windchest page; the anatomy every chest family shares is covered on the windchests hub.

In mechanical action the key is joined to the pallet by a direct mechanical linkage, with no electric or pneumatic power employed in opening the pallet. The Organ Historical Society’s description of mechanical action lists the parts that carry the motion: trackers that pull, stickers that push, backfalls that reverse the direction of travel, rollers on roller boards that carry the motion sideways across the chest, and squares that turn it around a corner. Pressing the key pulls, through whatever chain of those parts the builder laid out, on the pallet, and the pallet moves away from the opening it controls; when the key is released the linkage lets it close again.

The American Institute of Organbuilders’ guidelines, advisory recommendations rather than a binding standard, hold that a mechanical action should have at least one manual adjustment point per note in each divisional action group. Its purpose is regulation of that key-to-pallet chain. What is adjusted, and by how much, is technician work and is not described on this page.

A pneumatic motor under electric control opens the same pallet-and-slider chest without a long mechanical run from the console. Cook’s tutorial makes the point that the construction of the chest is independent of how its pallets are moved: the same chest can be opened by a direct mechanical link from the key, by a pneumatically assisted mechanical connection such as a Barker lever, or by an electrical connection in which a magnet opens a pneumatic valve that pulls a very short tracker attached at the pallet box.

In a pitman chest the pneumatic element is built around the valve itself. A pallet held by a leather pouch seals a hole in the topboard; pressing a key energizes an electromagnet that lets wind escape from the key channel, and the pallet lifts. Whether wind then reaches a particular rank is decided separately by stop magnets governing stop channels that contain the pitmans. The chest magnet at the head of that chain is an ordinary trade item: a Reisner brochure issued under the Organ Supply Industries name states that the Reisner chest magnet has been the standard of the industry for over three quarters of a century, and lists chest magnets, pedal pouch units, and a direct pallet magnet among its products. That standing is the supplier’s own claim, made in an undated brochure.

In a direct electro-mechanical chest, as the Organ Historical Society describes it, an electromagnet controls each pipe valve without an intervening pneumatic motor; the magnet’s armature moves the valve directly. The arrangement was patented in more than one form. The Estey Organ Company was assigned United States Patent 1,887,076, titled Direct electric action for pipe organs and granted in 1932 to Warren Samuel Russell, covering a bipolar-magnet and pivoted-armature pallet arrangement, so the phrase direct electric action was not exclusive to any one builder.

The magnets themselves span a wide range. Organ Supply Industries lists direct pallet magnets at 40 to 300 ohms, chest magnet coils at 90, 125, 150, 180 and 300 ohms, and stop action magnets at 28 ohms, with most magnets specified for roughly 10 to 16 volts DC. That is a supplier’s description of its own catalogue range; it establishes the spread of coil resistances in commerce, not what is fitted in any particular instrument. Seeing magnets and armatures rather than pneumatic pouches can support a qualified technician’s identification of this action class, but the observation is not conclusive, does not by itself establish who built the chest, and is not owner-level inspection guidance.

A pitman is not a pallet. The pitman is a small metal cylinder with a leather pad attached, and it works as the stop-selection element: it decides whether the wind admitted for a given key reaches a given rank. The pallet in the same chest is the wind valve that lifts for the key, and the leather pouch that holds it is the pneumatic element that lets it move rather than the valve itself. Three parts, three names, three jobs. The pitman chest and its two-control sequence belong to another page, so they are compared here only far enough to keep the vocabulary straight; the full mechanism is on the pitman windchest page.

Builders’ own designs stretch the word further. Inside the Austin Universal Air Chest, lightweight wooden trackers run across the windchest connected to all the valves of a given note, and small vertical rods attached to padded metal pallets control the access of wind to individual pipes. There the pallet is a small metal valve under each pipe rather than one valve under a whole note’s channel. The glossary definition still holds, a movable portion that opens or closes a hole leading to a pipe, but a reader should expect the pallet’s exact form to change from one chest design to the next.

A pallet can be made to answer both the key and the stop. In an Austin straight chest a pallet opens only when the key tracker moves and the stop bar crossing that tracker is in its raised position. With the stop off, the vertical bar pivots at the point where the pallet frame is attached, no force reaches the pallet, and the pipe cannot sound. The stop does not move a slider or a pitman; it changes whether the key’s motion is delivered to the pallet at all.

That is a different architecture from the slider chest, where the pallet under the key and the slider under the stop are two independent conditions that have to coincide. One consequence is that a stop failure and a note failure present differently on a slider chest, because they arise in different parts of the mechanism. Naming that difference is as far as this page goes. Which part is at fault in a given instrument, and what to do about it, is a diagnostic question for a technician and is handled in the service pages rather than here.

A pallet’s sealing face is leather, felt, or a laminate of the two, and the choice is made by duty. Organ Supply Industries catalogued white alum-tanned sheepskin, flesh side buffed, for valves and pallets, while listing stretched alum-tanned cowhide for reservoir ribs and soft, pliable alum-tanned sheepskin, cowhide, and kangaroo for reservoir corner gussets. A wholesale leather catalogue makes the same division by application rather than preference: chrome-tanned hairsheep for pouches, alum-tanned sheepskin in a thin gauge for valves and pallets, and stretched alum-tanned cowhide in a slightly heavier gauge for reservoir ribs. Pouch leather and pallet leather are different tannages doing different work, which is why a pallet facing is a specified material rather than a generic sheet of leather.

Composite felt-and-leather is a distinct material class of its own, made by laminating wool or polyester felt to valve leather with a flexible adhesive and supplied in graded thicknesses. The idea is not new. US Patent 1,100,045, granted to John T. Austin in 1914, specifies that each port is closed by a valve or pallet formed of a layer of felt with a layer of leather secured to each side of it, so the pallet facing in that claimed design is a laminate rather than a simple leather pad.

These are catalogue and patent descriptions of particular products and designs, not a specification that every chest follows. When leather is replaced across an instrument, pallet and valve facings are one item on a list that firms describe as also including reservoir ribs, corners, and gussets, pouches, primary and secondary pneumatics, chest and windline gaskets, wooden pipe stoppers, and tremulant and swell shade motors.

Reaching a pallet is designed in, not improvised. The American Institute of Organbuilders’ guidelines require removable bungs and panels wherever access to working parts is required, gasketed with cork, leather, or neoprene and securely fastened, so that a servicing technician can open the chest and re-seal it correctly. The gasket is the wind seal, and the guideline’s point is that the panel has to be re-sealed properly rather than merely closed; the same guidelines ask for self-compensating slider seals and rings of proven durability on slider chests, to prevent leakage and pressure variation. How a panel is opened, what is done inside, and how it is closed are technician procedures and are not described here.

How easy the pallet is to reach depends on the chest type. One organbuilder, describing a Blackinton-style electro-pneumatic slider chest, states that its pallets can be swapped out in a matter of hours, and contrasts that with chests whose valves are buried under pipework and toeboards. That is a single firm’s comparative view of a design it favors, published undated on its own website, rather than an industry measurement.

When a pallet covering is renewed on a historic instrument, conservation guidance expects material corresponding with the original. The New Zealand Organ Preservation Trust’s guidelines direct exactly that, and the same document treats replacing an original pneumatic action with all-electric units as a major alteration rather than a restoration. It is a 2002 issue of one national trust’s policy for historic instruments, and it may have been superseded, so it is a statement of conservation principle rather than a rule that binds every project. The distinction it draws is a useful one for any owner: renewing the facing on a pallet keeps the mechanism, while replacing what moves the pallet changes it.

For planning purposes, the useful starting record is a note of which chest family the instrument has, what material is on the pallets now, and where the gasketed access panels are; with that documented, a vague concern about wind or a note becomes a specific question a technician can inspect and plan around.