their introduction saw the withdrawal of the last of glasgow's old class 303 "blue train" trains which had been in service since 1960. although delivered to strathclyde in 1999-2002, they did not enter passenger service until 2001 due to a large number of problems (like other newly delivered juniper trains) and technical issues which plagued the new units at their introduction. spt had ordered 38 juniper units originally, but two were added to the order as a goodwill gesture, because of these problems.