Comparison and evaluation of various cycle-time models for yard cranes in container terminals

Yard cranes are important pieces of handling equipment in container yards. This study analyzes cycle times of various handling operations of yard cranes, including receiving, loading, discharging, and delivery operations. An operation cycle is divided into elementary movements, and formulas for expected time and variance of each elementary movement are derived analytically. Cycle times of various types of yard crane are compared with each other analytically and numerically. The accuracy of the formulas is evaluated through a simulation study.