It has been a hefty delay even by their standards but commuters today took their first trips on the latest Connex train - after a two-year wait.
Sixteen plush 375 trains today had their debut run on the Hastings-to-London line, replacing the old-style slam-door models.
Rail bosses today said their introduction heralded a new dawn for the industry.
The 375 has four carpeted carriages, wheelchair and pushchair access and in-car information screens.
Close circuit television is installed throughout.
Oliver Brousse, chief executive of Connex Transport UK, said: "I'd like to apologise to both our passengers and staff for the unavoidable but frustrating delays Connex has experienced whilst testing and introducing the 375 trains on to these lines.
"But the trains starting to run today are another step towards a better railway, at a time when performance is steadily improving and gives us confidence that we can deliver, together with Railtrack, a steep change in rail service."
The 16 trains run between Charing Cross, Hastings and Kent.
They are part of a fleet of 55 running throughout the South at a cost of £180 million.
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 The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.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 hereComments are closed on this article