These are in fact photos of the 15cm K.i.S.L. (or in some sources simply K.i.S.) 07 (Kanone in Schirm Lafette modell 1907) which was transported either on the trailer seen in the photos on the left towed by a tractor, or by rail, and used essentially as a railroad gun. When in the firing position the gun was as seen in the photos to the right with the AEF soldiers posing on the barrel.
