When the 4-6-0s arrived on the RGS they all held 2500gals in the tender. All were extended about a foot to hold more water. 3000gals it seems for the 25s tender( ow behind 20) and 3200gals for the 22, and 2900gals for 20. I have read that the 4-6-0s used more water than the 2-8-0s.
It is documented in more than 1 of the RGS story books about why they were restricted to the south end. Basically to heavy for the small rail at the time. It was said that they were pounding holes in the track.
Jeff Taylor
CRRM curator of equipment and rolling stock.