Deutz motor locomotive operating on the American controlled 'St. Mihiel Argonne & Berlin' railway 1918 (NARA111-SC-23667-ac)
Probably United States Army Signal Corps
Public Domain
Science,_Technology_and_Engineering
Geralt
CC0 1.0
Clock gears
Przemek Pietrak
CC BY-SA 3.0
Wheel_on_“Peggy,”_a_Lima_Shay_Geared_Steam_Locomotive_(SN_2172)
Steven Fine
CC-BY-SA 4.0
Science, Technology and Engineering
CC BY-SA 4.0