I've put my comments in bold to distinguish them, didn't want to have like 10 quotes in one post.
Of note is that my list is as is at 1/1/1920. This means anything decommissioned after that is still listed. Likewise, the 'to be built' is ONLY ships that will be laid down by the end of 1920.
Alright, I'm happy to pull together lists like this for each of the 3 major powers;
I've added a few notes:
2x OB Kearsarge (11500t, 2x2 13in/35, 16kts, 337mm / 70mm, 1900)
Totally obsolete due to superimposed turrets - Kearsarge was converted into a craneship before the Treaty was even proposed.
Kearsarge was used as a training ship in 1919, only decommissioned for conversion in May 1920.
Kentucky was also used as a training ship, decomissioned in May 1920.
3x OB Illinois (11600t, 2x2 13in/35, 16kts, 337mm / 70mm, 1901)
All decommissioned in advance of treaty
All 3 still in reserve at the beginning of 1920.
3x OB Maine (12600t, 2x2 12in/40, 18kts, 279mm / 64mm, 1902)
2 of 3 due to decommission, 1 in reserve
I made an error here, should be 2x OB Maine, as 1 already decommissioned (Missouri in Sept 1919), 2 in reserve.
5x OB Virginia (15000t, 2x2 12in/40, 19kts, 279mm / 76mm, 1906)
Seriously compromised by superimposed turrets, all due to decommission
But none decommissioned as of 1/1/1920.
6x AC Pennsylvania/Pittsburgh (13700t, 2x2 8in/40, 22kts, 152mm / 38mm, 1905)
San Diego sunk by mine 1918
Thank you, missed that.
4x AC Tennessee/Memphis (14500t, 2x2 10in/40, 22kts, 127mm / 38mm, 1906)
Memphis wrecked 1916
To be laid down;
5x BB South Dakota (43200t, 4x3 16in/50, 23kts, 343mm / 89mm)
Should be 6
Massachusetts only laid down 4/4/1921.
4x BC Lexington (43500t, 4x2 16in/50, 33kts, 178mm / 57mm)
Should be 6
Lexington and Ranger only laid down in 1921.