The Network Rail, Mk3 Lecture Coach, New Measurement Train, 975984 - Era 11 was a former Mk.3 TBS, was originally part of the prototype HST as E10000 (then W40000), before being converted into R&DD Laboratory Coach 15 'Argus'. The vehicle then served as DM&EE's Test Car 4 and is now a Lecture coach in Network Rail's 'New Measurement Train'. This coach has a yellow painted finish and measures at 303mm.