Complex sentence: It was constructed in stages between 1969 and 1982 entirely by voluntary labour, many of the volunteers being full-time permanent-way workers from Córas Iompair Éireann, now Iarnród Éireann.
Split into simpler sentences: It was constructed in stages between 1969 and 1982 entirely by voluntary labour. Many of those who participated in this arduous task were full-time permanent-way workers from Córas Iompair Éireann, now Iarnród Éireann.