Half of the British route was closed because more than 45,000 train workers walked out successively due to salary, work, and provisions.
Some routes do not have services, and where they operate, the train will only run between 07:30 and 18:30 BST. Other strikes are scheduled for Saturday.
Passengers are told only to travel by train if necessary.
This is the newest of a series of summer attacks and will change travel plans for workers, festival spectators, and those who lead to the cricket test match at Lord’s in London.
Mick Lynch, Secretary General of Railroad, Maritime, and Transportation (RMT) has warned that the dispute can take place “without time limit” unless the settlement of payments is reached.
In a letter to the Secretary of Transportation, he accused the government of using taxpayers to “save” private railroad companies, helping them avoid responsibility for the income lost due to the Train strike.
“The same company complies with government instructions to hold salaries, cut thousands of safety-critical railings, introduce special drivers’ trains, and close ticket offices throughout the network,” Mr. Lynch added.
A spokesman for the Transportation Department said: “Once again, for the sixth time since June, the union leaders chose to cause misery and disrupt the daily lives of millions of people instead of the 21st century. “
A total of 4,300 services are expected to run throughout the country on Thursday and Saturday, according to the Network Rail operator track. This is the highest number but during a series of national RMT attacks and train strikes.
However, it is still more than one-fifth of the ordinary service level.
Some places, including Portsmouth, Swansea, and Blackpool, will not have a train at all and there will be no service that runs north of Falkirk.
The service will also be completed earlier. The last train from London to Edinburgh on Thursday, for example, departs at 14:00, while the last train to Leeds departs at 15:05.
The train will also begin slower than usual on days after attacks and Train strikes.