taiwan railways' west coast mainline (wcml) electrification project was completed in 1978, leading wholesale timetable recast on the wcml. at about the same time, the new emu100 vehicles ordered for express passenger service on the wcml was introduced. up until this point, the highest-class passenger train on the wcml had been the diesel and electric locomotive hauled "kwan-kung (tourist) express", which was phased out of service on 25 april 1978. all express passenger schedules were re-allocated to a new class of deluxe electric express service, and the "chu-kuang express" (introduced earlier in 1970).