St. Andrew’s Episcopal Church · Ann Arbor, MI · standrewsaa.org January 2016

How is a Tracker Organ Constructed?Richards, Fowkes & Co. have provided a set of photographs showing the various parts of the organs they’re building in their workshop in Tennessee.

The bellows are the lungs of the instrument. This photo shows a large wedge bellows near the end of construc-tion. The bellows provide a stable wind supply to each keyboard division and pedals. Each of the bellows will have weights on top that set and maintain a consistent wind pressure regardless of how many stops are being used at any time.

1

Rollers are wooden shafts that rotate. They connect in-dividual keys to the tone valves at the base of the pipes, acting as the ligaments of the instrument. The photo shows rollers mounted onto a roller board, fitted with arms to receive and relay the movements of the keys from the keyboard to the wind chest.

2

3 The wind chest is a hollow box filled with compressed air provided by the bellows. Each ‘stop’ at the organ console represents a set of pipes of a particular tone col-or, with a different pipe for every note on the keyboard. Pulling the stop activates a slider under that specific set of pipes on the wind chest, making them available as a source of sound. The wind chest also contains a series of valves connected to the keyboard by a mechanical linkage. These valves govern the flow of air to each pipe, and even though a stop may be on, no pipes will sound until a key is depressed and its respective valve opens. This allows the compressed air to pass up through the pipe for that note, creating sound. The photo here shows the assembled grid for a wind chest. Each of the slots in the chest connects to a key in the keyboard. When the grid is complete a table is applied to the top side of the chest and the sliders are laid out.

1

St. Andrew’s Episcopal Church · Ann Arbor, MI · standrewsaa.org January 2016

The longer wood in this photo is the slider. When the organist pulls a stop this slider moves to line up with the pipe wind holes, allowing that stop to speak when a key is played.

4 5

Holes are then drilled for every pipe that is located in the chest.

6

Once the drilling is complete, the craftsman must clean up the holes to assure the proper function of the action.

Toe boards are then fitted into the wind chest, which seal the sliders to the chest. The slots for the sliders are under each toe board. The two chests in this pho-tograph are played from one keyboard in the organ.

7

2

St. Andrew’s Episcopal Church · Ann Arbor, MI · standrewsaa.org January 2016

The next component to be constructed is the bot-tom side of the chest, called the pallet box. A slot is made for each rib, or key in the keyboard. A pallet will be installed over each slot, and connect to the key through the roller board to open the air supply for that specific pipe. The photo shows a completed pallet box.

8

The pallet box is then installed. It is always pressur-ized when the organ is on, and needless to say, there can be no leaks. Each surface is leathered to ensure that the pallet box is airtight

9

10 The individual pallets are then milled. This pho-to shows the construction drawing for the pallet and pallet box. There are several sizes of pallets; as the pipes get bigger the dimensions of the pallets increase in size to provide an adequate amount of air for each pipe.

3 4

St. Andrew’s Episcopal Church · Ann Arbor, MI · standrewsaa.org January 2016

This building technique connects the organ player to the instrument. The manner in which the player presses and releases a key shapes the beginning and ending speech of each pipe. This provides an entire vocabulary for the organist to work with which is not available in an electro-pneumatic organ.

This photo shows pallets installed in the pallet box. Wires will be connected to each pallet, which in turn will connect the pallets to the mechanical action system in the keyboard.

11

This photo shows a cutaway profile of a wind chest. The wire coming out of the bottom of the pallet box connects to a tracker through a rollerboard and back to the keyboard. The pallet seals itself against the bottom table of the wind chest over the hole for that note. The small black pieces of lumber above the pallet box are the sliders. If a slider is pulled that note will play. Above the sliders are the toe boards, which usually consist of several layers of wood to ac-commodate the layout of pipes on the chest.

12

This photo shows a small home organ recently built by Richards, Fowkes & Co. It shows the keys, roller boards, and pallet pulldowns. Two of the windchest covers are open, showing the pallets inside the chest.

13

4