Tensile Testing
TMT has several test machines with tensile capacities ranging from a few pounds to several hundred thousand pounds. All of these machines use servo-controlled hydraulic cylinders to apply tension, and can be programmed to attain specific load or extension rates and high/low limits for automated tensile fatigue work. These machines can be configured to provide straight or skewed pulls on ropes, cables, and hardware of all shapes and sizes. These machines can be fitted with multiple sheave sets to allow tensile tests on hundreds of feet of rope or cable. Often, auxiliary instrumentation is used to measure various mechanical, electrical, and optical properties, and the data is graphically displayed and digitally recorded real time by our custom data acquisition system. A general list of our tensile test machines and their typical capacities is presented below.
| Machine | Tensile Capacity / lbf |
Bed Length, feet |
| BOS1 | 400,000 | 60* |
| BOS3 | 180,000 | 125* |
| Orange Beam | 30,000 | 15 |
| Kenobi | 50,000 | 30 |
| DUFF 4 | 370,000 | 80 |
| DUFF 5 | 370,000 | 80 |
| DUFF 6 | 370,000 | 80 |
| DUFF 7 | 370,000 | 80 |
| DUFF 8 | 100,000 | 30 |
| CEC1 | 8,000,000 | 20 |
| CEC2 | 600,000 / 1,300,000 | 130 / 65 |
| CEC3 | 2,500,000 – 5,000,000 | 250 |
| CEC4 | 280,000 | 45 |
| CEC5 | 300,000 | 100 |
Specialized Test Examples
Breaking Strength Test – Single-pull test to failure to attain failure load. Ropes and cables can either be straight or bent over a static or rolling sheave. Tests can also be conducted with a specified amount of induced twist or with one end of a cable free to rotate.
Tensile Fatigue Test – Cyclic-tension fatigue test to cycles to failure. Ropes can either be straight or bent over a static or rolling sheave. Test can also be conducted with a specified amount of induced twist or with one end of a cable free to rotate.
Tensile Characteristics Test – Tensile test with very accurate measurement of cable elongation, torque, rotation, and diameter versus tension. TMT has developed an extensometer and a “friction-compensated” swivel to facilitate accurate measurements of elongation, torque, and rotation. The friction-compensated swivel uses active compensation to minimize the effects of bearing friction, and it allows more accurate measurements of torque and rotation than possible using other types of swivels. This test is often used for lot acceptance of rope or cable, or cable development and analysis of cable characteristics. See Torque & Rotation for more information about Tensile Characteristic Tests.
Tensioner Hold Back Test – 2 to 4 track system applies a crush force of up to 100,000 pounds while a hydraulic cylinder applies an axial load. This test reveals slip interfaces at various axial tensions.