Train withdrawal incidents
On 13 April 2002, a fault was detected in a C751B train and it was subsequently withdrawn to Changi Depot for investigations. As the train was under warranty, the engineers from the manufacturers of the train and gearbox were flown in on 21 April. They subsequently detected metal fragments in the gearboxes, and those of another 20 trains. SMRT immediately withdrew all 21 C751B trains and suspended the Boon Lay – Changi Airport train through service, replacing it with the Tanah Merah – Changi Airport shuttle service. Train frequencies were also adjusted until early May, when 8 trains returned to service. By June 2002, all C751B trains had been returned to service and the through service was resumed.