There was widespread disruption across the First Great Western (FGW) rail network last Sunday as workers struck over jobs, safety and services.
A further 72-hour walkout is set for the bank holiday weekend.
The dispute stems from the introduction of new high-speed intercity trains. Talks with FGW bosses have made no progress over the core issues, said the workers’ RMT union.
It said these included “drivers being forced to take over door and dispatch functions which downgrades the safety-critical role of guards”.
The removal of catering services and the threat to jobs among train maintenance engineers have also provoked the strikes.