Another innovation Rodman developed was a replacement for the rear knob of cannons (a part of the area called a cascabel) which is used for fitting the gear that lifted and lowered the gun. Older designs had a knob that was small and round, which were found to easily break on the larger barrels being cast at the Fort Pitt Foundry. Rodman gave his cannon a short knob nearly as wide as the base of the barrel, a distinctive and easily recognizable feature of Rodman's guns. He also created instruments capable of measuring the internal pressure of his cannons. Rodman's contributions and the extent his work was utilized had been described as:
