712 is one of five inspection trolleys built in 1962 for CIÉ by Wickham of Ware. Designed to the Type 40 MkIIZ specification, it was equipped with a Ford Zephyr engine, and was used by CIÉ track gangs on inspections of the permanent way. 712 was withdrawn in 1997 and preserved by the Irish Traction Group, who loaned it to DCDR in 1998.

The railcar was used during the construction of the line to to Inch Abbey, but shortly afterwards was the victim of a considerable vandal attack. It has been in storage ever since, and today is located inside the new locomotive shed in need of a full restoration.