They were a smaller, lighter and less powerful version of the 001 Class and were originally intended for branch line passenger and freight (mixed traffic) duties.

When introduced they were painted an all-over silver livery which unfortunately dirtied quickly and was not a good advert for dieselisation.

In the next change black became the base colour with just a white relief around the top panel, which opened to a squared-off 'V' between the cab windows.

With the adaptation by CIÉ of its "Black and Tan" scheme in the mid-1960s, the locomotives received this livery with a white line at roof level to match the coaches.

The last CIÉ livery was of Golden Brown with a very broad black band covering the upper panels at the level of, and as wide as, the cab windows.

They were stored as soon as any problems arose (e.g. a seized engine or traction motor), and the whole class was formally withdrawn in 1993 (107/109) or 1995 (the others).