Kawasaki Heavy Industries & CSR Qingdao Sifang C151A

C151A for the supply of 22 trainsets for the North South and East West lines were initiated for future expansion, which is to expand the fleet as 106 trains were insufficient for the Boon Lay extension and Jurong East Modification Project in December 2007. On 6 May 2009, the Land Transport Authority announced that KHI and Sifang had won over Hyundai Rotem, Bombardier Transportation and Mitsubishi Heavy Industries to secure the contract at a cost of S$369 million, despite Hyundai Rotem offering the lowest bid at S$323 million for the order of 22 trainsets under Batch 1. Sifang handled the manufacturing and testing of the rolling stock, while KHI oversaw the project and design. The C151A contract was the first successful joint venture between these two companies in the international market. Also, in December 2011, 13 additional trains were purchased by LTA under Variation Order bringing the total number of trains to 35. With the delivery of C151A trainsets, trains were actually operated on the East–West Line until October 2013. C151As were temporarily suspended from the North–South Line during the MRT disruption in 2011, starting from 7 May 2012 all the way until 23 October 2013. SMRT engineers detected arcing problems on one of the C151As, but no evidence was shown that it was the root cause of the service suspension in 2015. During the suspension of the C151A running on the North–South Line, SMRT had investigated and found impurities in aluminium bodywork caused the cracks found in structural components, including the sub-floor, which is a compartment located under passenger floor. Its role is to hold equipment box and electrical wires and bolster function parts connecting the car body to the bogie. Affected trainsets were sent back to China progressively between July 2014 and January 2020, before the COVID-19 pandemic. Refurbishment All 92 trains from the KSF fleet, consisting of C151As, C151Bs and C151Cs will undergo refurbishment works from 2026 onwards, and is expected to be completed by the mid-2030s. ==Tender==

The tender for trains under the contract turnkey 151A was closed in January 2009. The tender results were published in May 2009. ==Equipment==

Main propulsion controller The C151A trains are the third commuter type Electric Multiple Unit (EMU) to feature electric systems fully manufactured by Fuji Electric. Propulsion is controlled by VVVF Inverter with 2-level IGBT semiconductor controller, rated at 415 kV. Each inverter unit controls two motors on one bogie (1C2M), and one motor car features two of such units. Motors are three-phrase AC induction type, model MLR111, with a maximum output of . However, the main difference is that the traction for the trains is higher pitched than the ones from C751B trains which are lower pitched. Bogies The C151A trains use the monolink axlebox type bolsterless air spring bogie. There are no major technical differences between a trailer and motor car bogie other than additional electrical components for the latter; similar to the Kawasaki and Nippon Sharyo C751B trains. However, the Beijing Subway Rolling Stock trains were also equipped with bolsterless air-spring bogies manufactured in China. Auxiliary systems A break from tradition, the C151A trains features auxiliary inverters for its electrical systems on all six cars of the train. Previously, auxiliary inverters were mounted only on motor cars. The VVVF Inverter is controlled by IGBT semiconductors and rated at 80 kV. A battery charger is built with the inverter and provides output. Linear Variable Differential Transformer (LVDT) 3 trains (Sets 501/502, 531/532 and 533/534) are equipped with LVDT. This is to inspect the third rail. ==Interior==

The interior of the C151A trains depending on each car, features the shades pink, blue and turquoise seats. Priority seats are in darker shades. The floor of the train is also grey and interior walls are white similar to that of Kawasaki Heavy Industries & Nippon Sharyo C751B trains (except floor colour). ==Train formation==

The coupling configuration of a C151A in revenue service is DT–M1–M2+M2–M1–DT. The car numbers of the trains range from x501 to x570, where x depends on the carriage type. Individual cars are assigned a 4 digit serial number. A complete six-car trainset consists of an identical twin set of one driving trailer (DT) and two motor (M) cars permanently coupled together. For example, set 535/536 consists of carriages 3535, 1535, 2535, 2536, 1536 and 3536. • The first digit identifies the car number, where the first car has a 3, the second has a 1 & the third has a 2. • The second digit is always a 5, part of the identification numbers • The third digit and fourth digit are the train identification numbers. A full-length train of 6 cars have 2 different identification numbers. For example, 535/536 (normal coupling) or 535/548 (cross-coupling). • Kawasaki and CSR Qingdao Sifang built sets 501 – 570. ==Operational problems==

On 5 July 2016, a Hong Kong-based non-profit news organization FactWire had broken the news of the C151A trains suffering from multiple defects relating to Chinese-made materials and posted the entire investigative works on YouTube. Factwire allegations These are the list of allegations mentioned in their YouTube video since C151A entered into revenue service in 2011 (27 May 2011). as well as the first Land Transport Authority press release at an hour after first SMRT's press release. and also the subsequent official position on Singapore government's online FAQ portal 'Factually' which quotes sources from the Facebook page of Land Transport Authority hours after the initial press release. Reactions This incident was a source of public concern among Hong Kongers because subway operator MTR had ordered fleets of a new train from the same manufacturer CRRC Sifang. The news was quickly reported in other Hong Kong media. The incident also created a public uproar in Singapore, generating a public reaction. Some of these discussions included criticism of the Land Transport Authority (LTA) and SMRT for the cover-up about the defective trains, while others questioned the quality of the Chinese-made trains. The LTA released more technical details on 6 July 2016 claiming that 5 of the 26 defective trains had been rectified, including photos illustrating the 'hair-line crack'. The authority also named an independent third-party assessor, TUV Rheinland who shared the same opinion that the defects are "not safety-critical". gained traction amongst the public. The consortium refuted the rumor on 7 July 2016 and threatened to take legal actions. The LTA also publicly dismissed the allegations in a press statement. The link to the original rumor was deleted soon after the response from the authorities. in order to refute a subsequent FactWire report claim. LTA also stated that it "considered that the contractor was able to quickly identify the cause of the defects, take responsibility and carry out the necessary action promptly to rectify the fault" and gave the consortium the "highest quality score" as the basis for awarded them subsequent train contracts (C151C and T251) in 2015 despite the defects were discovered since. republished a CaiXin Online article originally published in March 2016 by the China Railway Construction Corporation blaming the China Railway Corporation for the decline of quality standards. According to the former, 60% of all railway incidents in China and 90% of all railway disruptions during 2015 can be attributed to CRRC manufactured trains not meeting quality or maintenance standards, with 210 instances resulting in death or injuries. Political furor in Singapore The incident became a political issue as opposition politician Gerald Giam from the Workers' Party questioned the transport authority for awarding the consortium a "top quality score", among other statements in his Facebook page. The party later issued a second statement that their MPs would file 17 questions in Parliament about the issue. Official statement from Transport Minister On 12 July 2016, Transport Minister Khaw Boon Wan released an extensive statement about this issue. These are the key points that Khaw have made: • The reason that this incident was not reported earlier in 2013 is because going public for something that was "not a major event" might have caused unnecessary panic to the layman since any engineers would have known that not all cracks are the same. However, he admitted that sometimes routine matters can be spun out of control, just like in this incident. • Land Transport Authority would have consulted with Ministry of Transport and go public if this incident happens to be a safety issue OR affected train capacity even if the incident does not affect safety because they need to explain the slowing down on the goal of increasing mass rail transit capacity.In this case given that only one train is sent for rectification at a time, planned to assemble their trains in China with Hyundai Rotem and Construcciones y Auxiliar de Ferrocarriles the exceptions who will assemble their trains in South Korea and Spain respectively should they have won the T251 tender. Reaction from the Analysts and FactWire after Minister statement • Senior Transport Correspondent for Straits Times, Christopher Tan published an article on 14 July 2016 in a response to the entire saga. He started with both LTA and the train manufacturer are addressing the flaws head-on deserves credit which regretted the false statements that Singapore minister had made 2 days ago. Specifically, FactWire regrets the minister has suggested that FactWire could be part of politically motivated anti-China factions in Hong Kong and as a result Singapore become a convenient bullet and collateral damage during the press release on 12 July 2016. FactWire also reiterates that it is an entirely crowded funded news agency being independent of any commercial or political interests. ==Incidents==

On 15 November 2017 at approximately 8.18am, 2 C151A trains set 535/536 & 547/548 collided at Joo Koon MRT station. The collision resulted in 38 injuries, including two SMRT Trains staff members. It was the second train collision in Singapore MRT's history, after the Clementi rail accident. ==References==