Mechanical Bells PDF The W.L. Jenkins Company's mechanical bells are made of heavy duty cast iron construction of the operating parts and a gong shell manufactured in our plant to the Jenkins heat-treated bell specifications. APPLICATIONS The W.L. Jenkins Mechanical Bells can be used in a variety of applications including Transportation ferries, amusement park rides, trolly cars and trams, and rail cars, Manufacturing Facilities, steel mills, mining operations, refineries and foundries.