All changes to tower
| Date | Change | Source |
|---|---|---|
| 30 Nov 2019 | 1-6: turning added | Tim Jackson via e-mail |
| 18 Jan 2019 | Wed PN is predictable (not merely 'with exceptions') S | 2019/p59 via RW |
| 9 Sep 2017 | frame: material,truss,layout added | Mike Chester via e-mail |
| 29 Sep 2010 | URL added | Frank Lewis via e-mail |
| 27 Apr 2007 | Tenor is NOT 8-3-24 in Ab but 8-3-22 in A (nominal: A-28c) | Andrew Higson via pNBR |