Greater Anglia has run its first tests on new trains due to come into service on the East Suffolk line between Ipswich and Lowestoft.
The run, in the early hours of the morning, tested whether there would be any snags for the trains on the route. The train stopped at all the stations for checks to be carried out.
The new Stadler bimode trains - which can run on either diesel or electric power from overhead lines - are expected to be introduced on the route before the end of the year.
They should have taken over all East Suffolk line services by the end of next year.
Eventually these trains will be used to reintroduce through trains from the line to London - there will be several trains a day which continue from Ipswich to Liverpool Street using the overhead lines.
The new trains are also being tested on the line from Ipswich to Cambridge and Peterborough, and in Norfolk on the line from Norwich to Sheringham and Cromer, which is due to be the next to see the new trains introduced into public service.
A spokeswoman for Greater Anglia said: "The testing has to be done at night because there are no other trains on the track and we can check everything.
"But it is good that the testing is now under way - we are looking forward to introducing these new trains across the region."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here