As with the Great Bear, the rear (probably, if pivoting) Bissel/pony truck has inside bearings and would have been better with an outside bearing Cartazzi as on Gresley' A1. The boiler seems excessively long and was it superheated? I have read descriptions from 1920s Railway Magazines where it was employed out of Kings Cross, but can find no major criticisms of their capacity for steaming. I guess, as uou say, they were adequate but not capable of development as were the A1, into A3.
As with the Great Bear, the rear (probably, if pivoting) Bissel/pony truck has inside bearings and would have been better with an outside bearing Cartazzi as on Gresley' A1. The boiler seems excessively long and was it superheated? I have read descriptions from 1920s Railway Magazines where it was employed out of Kings Cross, but can find no major criticisms of their capacity for steaming. I guess, as uou say, they were adequate but not capable of development as were the A1, into A3.
Uskeuai