Threat of Robots Replacing Half of Workforce Colors Longshoremen Talks on West Coast

West Coast shippers and dockworkers are struggling to reach a labor agreement as terminal operators replace up to half the laborers at some ports with robots, in the largest technological change in half a century.

The two sides are discussing how to retrain and preserve jobs for dockworkers as automation reduces the number of positions at one Los Angeles terminal by 40 percent to 50 percent after changes are completed in 2016, according to a Harbor Department report released in April.

“In the U.S., the extent to which automation of container terminals affects the number of longshoremen’s jobs depends on ...