Last week, having the majority of the structure in place, the team from Nicholson made significant progress on the installation of Betty’s restored tracker action. Tracker action is a system of solid shafts and levers which open pipe valves when the keys are pressed. Betty was originally built with this system when she was built in 1865 but due to fads in the early 20th century the system was replaced with pneumatic action. The pneumatics were at the end of their life and needed replacement, so the recommendation was to go back to a mechanical tracker action.
The cedar strip trackers which are held in tension will later need adjusting by turning the end pins by which they connect to the rollers. The rollers translate the signal on the keys to the position at which the corresponding pipes are located. The trackers need to be precisely the right length, short enough to ensure responsiveness of the keys but no so short that there might be sufficient leakage to cause a pipe to sound without the key being depressed.
With the trackers in, some of the first pipes started being fitted. The first wooden pipes being fitted in the back of the Organ chamber are actually so long they are mitred so that they turn a 90 corner at the end so that they can fit in the height of the organ chamber.
Getting the pipes into the back of the chamber, past the structure and trackers, took some care, as you can see from the following sequence of photos.