Southern was forced to cancel more than 700 trains - a third of the service - during the first day of a strike by guards. It is thought up to 300,000 passengers in Sussex, Surrey, Kent and Hampshire were hit with cancelled trains or having to make alternative plans.
The strike ends at 11am tomorrow but disruption will continue all day as trains and staff will be in the wrong part of the network.
Southern say they did run 1,400 trains. This was possible because 40 per cent run without guards, and managers were operating other services. This was in line with the planned strike service.
The company say they plan to run the same service on Wednesday.
The RMT says support for the action was "rock solid" and it expects the same tomorrow.
The dispute centres on changes to the role of the guard, with drivers closing train doors instead. Southern say they want to make staff more visible and new On-Board Conductors would spend more time helping passengers. They say there will be no job losses or pay cuts.
The RMT says it believes guards no longer closing doors will put safety at risk and it fears jobs will be cut and working conditions reduced.
No peace talks are planned and four more days of action are to take place from May 10th to 14th.