This charming little loco is an H&B Rly Class 'K' 0-4-0 well tank, which was one of a small class of 6 engines built by Kitson & Co in Leeds between 1886 and 1889. These were numbered 43 thru' 48 and were used in the H&B Rly docks area in Hull particularly for shunting 4-wheel bogies for carrying limber to the stock yards - note the additional heavy timber buffing blocks on the buffer beams for that purpose. The building behind is the rickety timber engine shed located on Alexandra Dock, which was eventually demolished by the LNER due to its poor, unstable condition.
Recommend reading is the book by M. A. Barker, titled 'An Illustrated History of Hull and Barnsley Railway Locomotives published by Challenger Publications and from which these loco details are drawn.
[Mike Morant collection]