Reg Rogers (The Americans, The Knick) and Tzi Ma (24, Million Dollar Arm) have signed on as series regulars for the fifth and final season of AMC’s Hell On Wheels, joining Tim Guinee who was recently promoted to regular, and Byron Mann.

Rogers, repped by Innovative Artists and Brookside Artist Management, will play James Strobridge, the tough-as-nails construction superintendent for the Central Pacific Railroad. Losing an eye to a blasting accident hasn’t quieted his temper or tempered his sense of humor. He lives with his wife and six adopted children in a train car at the end of rails. Ma plays Tao, who comes from a village in Guangdong in Southern China, and is now “head man” for a group of Chinese railroad workers on the Central Pacific. A former scholar and graduate of a British engineering school in China, his natural leadership abilities and facility with the English language make him essential to Cullen’s work on the Central Pacific. He’s a highly capable man but harbors a secret, and goes out of his way to avoid attention.

Rogers was most recently seen in the Tony-nominated Broadway revival of You Can’t Take It With You opposite James Earl Jones and Rose Byrne. On the TV side, in addition to recurring roles on The Knick and The Americans, Rogers also recurred on Boardwalk Empire and Flesh And Bone. Ma recurred as Cheng Zhi, nemesis to Kiefer Sutherland’s Jack Bauer on the hit series 24 and later on 24: Live Another Day. His other credits include the Coen brothers’ remake of The Ladykillers, as well as roles in Rush Hour and Rush Hour 3, and TV series Satisfaction and American Dad.

Hell On Wheels began production on its 14-episode fifth and final season last month, with seven new episodes set to premiere this summer and the final seven episodes of the series following in the summer of 2016.