Weld ocean-going hulls and hatches together on massive ships.
Operates hydraulic press that forces hard steel hob into soft steel block to form molding die: Receives premarked soft steel block and specified hob from set-up worker. Places block in retainer ring of press and positions hob on block. Places plug block over hob to hold hob in alignment. Turns handwheel to raise ram which holds block and hob in place. Starts pumps to build up prescribed hydraulic pressure. Pulls lever to exert pressure on ram which embeds hob in soft block to specified depth, forming impression die. Removes block manually and clamps it in vise. Taps block with hammer to loosen hob and removes it from block. Inspects die for defects, such as rips or flaws, using magnifying glasses.