Joo Koon MRT station

On 18 June 2017, Tuas Link station superseded Joo Koon as the western terminus of the East West Line.[6] During the initial opening stage, westbound trains alternated between terminating at both stations.[7]

On 15 November 2017 at approximately 8.18am, 2 C151A trains collided at Joo Koon MRT station. A train fault caused the first train heading in the direction of Tuas Link to stall at the station. A minute later, a second train stopped behind the first and then "moved forward unexpectedly", resulting in the collision. 36 passengers and 2 SMRT staff sustained light to moderate injuries, and were conveyed to Ng Teng Fong General Hospital and National University Hospital. This is the second of such incidents after 5 August 1993, with the first being when 2 C151 trains collided at Clementi.[8][9][10][11][12][13][14]

As a result, train services between Tuas Link and Boon Lay stations were temporarily suspended on both directions for 2 hours on the day itself and for the entire day on 16 November, resulting in westbound trains terminating at Boon Lay station.[15][16]

An update by the Land Transport Authority (LTA) & SMRT on 16 November stated that LTA and SMRT had decided to isolate for up to one month the operations of the Tuas West Extension, which ran on the new signalling system, from the rest of the east–west line, which ran on the old signalling system, in order to enable LTA and Thales engineers to carry out further assurance checks.[17]

Train service on the Tuas West Extension between Gul Circle and Tuas Link resumed operations on 20 November that year, using the new signalling system. The rest of the East West line continued to run on the old signalling system between Pasir Ris and Joo Koon. However, train services between Joo Koon and Gul Circle were suspended until 27 May 2018, though free bridging bus service was available between the two stations.[17][18][19][20][21][22] Continuous service to Tuas Link resumed in stages.[23]