A professional who controls shrink-pit furnace to assemble hoops and liners to tubes to form cannon barrels. Respnsibilities include:

• Positions steel blocks in shrink-pit to form angle for subsequent positioning of tube so that breech end of tube will be at floor level.
• Cleans and oils contact surfaces of parts with gasoline, oil, and graphite to facilitate assembly.
• Lowers hoops into furnace, using hoist.
• Moves furnace controls and observes thermocouple pyrometer and recording potentiometer to heat furnace to specified temperature.
• Guides cold tube, lowered by crane, through hot hoops in furnace.
• Turns water valve on cooling ring and lowers ring into furnace, using hoist, to spray hoops and shrink them onto tube.
• Reheats hoop and tube assembly, guides liner into tube, and regulates water spray to shrink tube onto liner.