The 101 Class (DL) became the answer to the immediate problem working in conjunction with the newly acquired British Rail Mark 2 coaches.

The 101 Class of NIR consisted of three mainline diesel-electric locomotives designed for use with the Enterprise passenger services between Belfast and Dublin.

The locomotives were fitted with buckeye couplers as standard and had air brake capability for operation with the Mark 2 coaches.

They were visually, mechanically & electrically very similar to the 1,000 mm (3 ft 3+3⁄8 in) metre gauge KTMB class 22 (Keretapi Tanah Melayu Berhad - Malaysian Railways) locomotives built by English Electric at around the same time, however these had had a Co-Co arrangement and an uprated power unit.

However, the attempt to restore 102 did not occur because of a series of external issues, and so the locomotive was left in storage in the Whitehead sidings.

In January 2012, 102 was transported with fellow UFTM resident CIE 113 Class B113 from Whitehead to Cultra under the cover of night.

Although 102 was able to operate, albeit in a limited capacity due to the extent of engine repairs required, neither was mechanically fit enough to make the trip under their own power.

Due to pressure for space as a result of the arrival of B(141) class locomotive B142 from Inchicore, attempts were made to seek a buyer for 101.

[2] When delivered the locomotives were painted in an unlined maroon livery with, on the ends, a "flowing V" in a golden yellow colour.

102 later carried a slightly darker shade of blue with black cab surrounds and yellow end panels.