Aloha
We have tentatively ID’d this loco as Kahuku plantation No. 4. #4 appears on the spot plate, and also note the handrail extending around the stack and above the headlight. KP no. 4 had this distinct feature. We are not sure about the building though, but a track layout in Sugar Trains shows multiple rail / building locations at the mill site. Another good reference is Treiber’s book, Hawaiian Railway Album pages 196 – 199 and Conde's Sugar Trains page 303. Kahuku Plantation RR was locate on the North Shore of Oahu. My thanks to Bob Paoa for his review and feedback on this.
KPRy 4, 0-6-2T, BLW31287, 7/1907
Used on the H&HRR in the early 1950s.
John Goldie