The huge scheme started in 2015 and will make the carriages of the firm’s 112 Class 375 trains lighter, brighter and more comfortable for passengers.
And now the refresh programme is just over the half way mark as 65 trains have been returned to service.
The work on the trains, which run on Southeastern’s routes between coastal Kent and East Sussex and central London stations, includes a complete re-spray outside and a repaint internally.
New carpets and lino have also been laid, replacement windows put in place where needed, and all seats have been removed from carriages and given a deep dry-clean and new seat bases.
Each Class 375 – which has either three or four car units - takes around three weeks to refit at the Derby plant.
The refresh work, which started when the trains were 15 years old and half way through their 30 year life expectancy, is known as a mid-life refresh and involves around 3,500 man hours per train using a team of 35 skilled fitters and technicians.
And in total, 20,500 litres of paint will have been used when all 112 trains are completed (9,600 litres internally and 10,900 litres externally).
Sixteen thousand four hundred sq metres of carpet will also have been used – enough to re-carpet around 170 average-sized three-bedroom family homes.
In addition, 6,400 sq metres of lino will have been put in place and more than 26,000 seats on all of the trains will be taken out of their carriages for refurbishment.
Mark Johnson, Engineering Director at Southeastern, said: “I’m very pleased that we are now over half way through this major and extremely worthwhile job that involves giving these trains a thorough refresh. Our feedback from passengers shows they want their trains to be cleaner and more pleasant and we are carrying out this work, as well as other cleaning work on all our trains, as we are committed to improving our service for our passengers.
“It’s great that we are able to work with our partners to carry out this refresh to our trains, which account for almost one third of our rolling stock. I’m sure our customers are noticing the difference as more and more of these newly refitted trains are rolled out.”