F22B13/00—Steam boilers of fire-box type, i.e. boilers where both combustion chambers and subsequent flues or fire tubes are arranged within the boiler body
F22B13/06—Locomobile, traction-engine, steam-roller, or locomotive boilers
F22B13/10—Locomobile, traction-engine, steam-roller, or locomotive boilers with auxiliary water tubes inside the fire-box
F22B13/12—Locomobile, traction-engine, steam-roller, or locomotive boilers with auxiliary water tubes inside the fire-box the auxiliary water tubes lining the fire-box