CIE used Cravens/Park Royal stock and then Mk2D stock until 1976 when someone blew up the line and this happened..
They went back to cravens after that until the mid-late 80's when the Mk2's returned.
NIR ordered 3 x 101 + 8 X Mk2B's in 1968 and they entered service on 4th July 1970.
During the winter it ran as 101+5 Mk2 in push-pull mode and 8 x Mk2 top and tailed by 101's in the summer.
5 more Mk2C's were ordered in 1970 so the train would be 12 coaches top and tailed by 101 in the summer and 5-7 coaches in push-pull during the winter.
In 1980 NIR bought 12 more Mk2 and the two 111 class locos. Some of the original ordered coaches went into 80 class sets to replace bomb damaged vehicles.
At the time any remaining coaches that were not for the 80 class were converted from 3-pipe to 2-pipe air braking.
4 more coaches and the 3rd 111 were bought in 1982 to make up a second 9 coach set.
On a typical weekday the two NIR sets and one CIE/IR set would be in use.