| Type: Free length: Outside diameter: Total coils: Active coils: Wire size: Wire type: Ends: |
Compression 6 1/8' 2 7/8' 5 3 5/8' Oil tempered Squared and ground |
THIS SPRING, shown next to a 1½-liter bottle of water for scale, is a shock absorber used at the bottom of a mine shaft to prevent ore cars from jumping off the track. A railroad tie is placed across the tracks with one of these springs at each end. When an ore car hits the railroad tie, the springs compress and bring the car to a safe stop.
The spring was coiled cold on a lathe at Betts Spring Company in San Leandro, where I worked for a while. Six springs were made, of which four were shipped to the customer and one destroyed in testing. Thirty tons of load failed to set it solid.
If you talk to Betts, they may tell you they still have someone who's crazy enough to coil this spring cold. I could be wrong, but frankly I doubt it.