The carriages will re-enter service from late 2018
Iarnród Éireann is to refurbish a fleet of 28 carriages in response to customer demand.
The firm has issued tender notices for work on the carriages, which have been out of service for six years.
Irish Rail say while they are planned to be used in the Limerick area, they will free up other trains for use in the Greater Dublin Area.
The carriages, which are known as the 2700-class commuter fleet, will re-enter service from late 2018 and into 2019.
The trains originally began operating in 1998 and were withdrawn in response to the economic downturn and falling passenger numbers.
Irish Rail say with passenger numbers growing again, it plans to refurbish them and return them to service.
A total of 42.8 million passenger journeys were made in 2016, approaching the peak levels of 45.5 million from 2007.
The tender notice invites companies to quote to undertake refurbishment works - including heavy maintenance on key systems, replacing seating and flooring systems and works on electrical, mechanical and body work.