Arthur handed him a heavy ball-peen hammer. Jim swung, striking the assembly. Clang! Again. Clang! On the third strike, the wheel gave a lurch, spinning freely.
"She’s breathin’ heavy tonight, Jim," Arthur grunted to his fireman.
Jim dropped his shovel and moved to the side of the boiler. He grabbed the handwheel of the soot blower, a heavy iron crank. He grunted, putting his back into it. The metal groaned, frozen by heat and age.
: Clean tubes allow more heat to be absorbed into the water/steam, lowering the final exhaust gas temperature.
: Removes soot that acts as an insulator, ensuring the boiler doesn't need extra fuel to produce the same amount of steam.