Project details:

Trigon Pacific Terminals Ltd. (formerly, Ridley Terminals Inc. (RTI)) operates a bulk materials handling terminal, located at Prince Rupert’s Ridley Island, for the export of metallurgical coal, thermal coal, petroleum coke. CWA was retained by RTI to conduct a fatigue analysis and service life prediction of their major materials handling equipment, including two shiploaders and three stacker-reclaimers. The objective of the study was to provide RTI with valuable information to facilitate their decision-making on asset management, including capital upgrades and equipment replacement considerations for the terminal’s long-term planning.


Prior to conducting the analysis, CWA began by reviewing all relevant documentation, drawings, information, and historical records on equipment and operations. The review found that there had been a multitude of modifications, upgrades, and replacements which created complexities in generating models and predicting the remaining fatigue life. Predicting the number of load cycles on the shiploaders and stacker-reclaimers was also a challenge as many different loading conditions had to be considered.


To build the most accurate model, extensive research was conducted on all shop drawings including all the equipment modifications over the years. Computerized structural models of the equipment were then developed to determine the maximum stress range under different prescribed loading conditions, and from there, predictions of the remaining life of the equipment. Based on consideration of the various conditions, fatigue life was determined to be variable across different areas of the equipment. The study analysis included:

  • Extensive review of all relevant documentation, drawings, information, and historical records of existing equipment that had undergone numerous modifications since commissioning.
  • Generation of RISA-3D structural models to determine the maximum stress range under various loading conditions.
  • The identification of areas with high risk of equipment failure.
  • Computed expended fatigue cycles based on historical data and compared available fatigue life against this data for prediction of the remaining fatigue life.
  • Provided recommendations on operational and maintenance programs based on results of the study.

Upon completion of the analysis, engineering commentary and recommendations based on the results of this study were provided to RTI to allow for future operations and maintenance planning.