Parts of a locomotive bell
Bells on trains are not unlike bells atop school houses, or within church steeples, or at firehouses. Locomotive bells share some common characteristics with these other types of bells, but maintain a few distinct characteristics. Typically, locomotive bells measure between 11 and 17 inches in diameter (measured from lip to lip) and can weigh hundreds of pounds.
When we refer to a locomotive bell, we most often refer to the entire bell assembly, which includes a:
- Bell | The cast bronze or brass bell that is rung to announce a moving train.
- Yoke | The cross piece from which a bell is hung and swung.
- Pull-Arm | The lever that rotates the yoke, causing the clapper to connect with the bell.
- Clapper | A metal shaft terminating in a solid sphere that swings back and forth inside to strike the bell and make it ring.
- Rope | Connects to the pull-arm, allowing the engineer to ring the bell from farther away.
- Cradle | The iron or steel framework that securely fastens the bell to the train or engine.
Bells on large freight or passenger trains were almost always cast in bronze or brass, but a few examples exist of iron or steel bells cast for smaller diesel locomotives.
Image: A 600-class steam locomotive manufactured by Brooks Locomotive Works with a bell mounted atop the smokebox idles in storage near Dump No. 6 after construction of the Panama Canal, photographed May 22, 1915. Courtesy: National Archives and Records Administration.