Running with a bogie 5000 gallon self trimming tender.
Robert Waterman says "Ex Lord Nelson tenders were fitted to 30912 and 30921. I have seen it postulated that this was for increased water capacity but I understand the real reason was for increased braking capacity when working freight - more common at the end of their operating lives.

I believe one of these two was sent down on a summer Saturday Lymington working (which was quite usual in the 1957 - 62 period) only to find that it wouldn't fit the Brockenhurst turntable. Some hurried loco re-oganisation would have been necessary!"