On 23 December 2011 the Department for Transport announced that the Class 460s would be split up and sixty carriages rebuilt to be incorporated with South West Trains' one hundred and twenty Class 458 carriages (30 4-car units), resulting in 36 five-car Class 458/5 sets.
 The remaining four carriages were stripped for spares and then scrapped.
 This £42m scheme was devised by Porterbrook the owner of both fleets.
The new 5-car sets were designated Class 458/5 and coupled together to form 10-car trains to provide extra peak capacity on suburban services into London Waterloo.

Porterbrook signed the deal with South West Trains in January 2012.
The work was carried out by Wabtec's Doncaster Works and Brush Traction, Loughborough (Drive vehicles) on behalf of original builder Alstom.

The first two of the 5-car sets were delivered in October 2013, and underwent testing ahead of the introduction of the first 10-car train into service in December 2013.
Passenger service started in March 2014.

It involved replacing the existing retractable gangways and couplers between coaches.
The cab ends both on Class 458 and on Class 460 driving vehicles were redesigned to be compatible with the Class 450 Desiro fleet.
The "Darth Vader" nose cones were discarded.
New Train Management System software was installed to improve reliability.
Internal refurbishment included reconfiguring the seating layout to provide more standing room for passengers.

Traction units on the Class 460 vehicles were to be re-geared from 100 mph (161 km/h) maximum, not required on the services for which the trains will be used, to 75 mph (121 km/h) maximum to avoid overheating.
Automatic Selective Door Opening was installed for use at a few suburban stations where it is not practicable to lengthen platforms.
On 23 December 2011 the Department for Transport announced that the Class 460s would be split up and sixty carriages rebuilt to be incorporated with South West Trains' one hundred and twenty Class 458 carriages (30 4-car units), resulting in 36 five-car Class 458/5 sets.  The remaining four carriages were stripped for spares and then scrapped.  This £42m scheme was devised by Porterbrook the owner of both fleets. The new 5-car sets were designated Class 458/5 and coupled together to form 10-car trains to provide extra peak capacity on suburban services into London Waterloo.
Porterbrook signed the deal with South West Trains in January 2012. The work was carried out by Wabtec's Doncaster Works and Brush Traction, Loughborough (Drive vehicles) on behalf of original builder Alstom.
The first two of the 5-car sets were delivered in October 2013, and underwent testing ahead of the introduction of the first 10-car train into service in December 2013. Passenger service started in March 2014.
It involved replacing the existing retractable gangways and couplers between coaches. The cab ends both on Class 458 and on Class 460 driving vehicles were redesigned to be compatible with the Class 450 Desiro fleet. The "Darth Vader" nose cones were discarded. New Train Management System software was installed to improve reliability. Internal refurbishment included reconfiguring the seating layout to provide more standing room for passengers.
Traction units on the Class 460 vehicles were to be re-geared from 100 mph (161 km/h) maximum, not required on the services for which the trains will be used, to 75 mph (121 km/h) maximum to avoid overheating. Automatic Selective Door Opening was installed for use at a few suburban stations where it is not practicable to lengthen platforms.
British Rail Class 460