History
Early Stages
Planning of Technical Specifications
In 1983, the Provisional Mass Rapid Transit Authority (PMRTA) of Singapore outlined several standards in its tender documents for the rolling stock under Contract 151. These included automatic and air-conditioned trains, dust- and water-proof design, functional and aesthetic carriages, and should have a life expectancy of about 30 years.
PMRTA said in 1983 that each C151 train would initially comprise four carriages, each 23 metres long, and would be controlled by computers on board. The C151 trains, made of aluminum or stainless steel, which are relatively easier to maintain, will start at the press of a button, accelerate, slow down, and stop automatically at the next station.
The authority, who was studying propulsion systems to power the C151 trains, emphasised its position to choose tried and tested technologies, such as the direct-current (DC) chopper control system, despite proposals by a Finnish firm to use alternating-current (AC) traction drives, as used by the Helsinki Metro rolling stock at that time.
PMRTA became the MRT Corporation (MRTC) in October 1983; it held talks with a high-level delegation from Japanese railway engineering, focusing on the DC chopper control technology the country pioneered since 1968, which at the time was touted to be energy-efficient, economical to maintain, and promised a smoother ride for passengers.
Pre-qualification and Tendering Process
In April 1983, PMRTA announced that 34 groups of companies, primarily consortiums and joint ventures, had been pre-qualified for Contract 151: Electrical Multiple Unit Trains (Rolling Stock) following the PMRTA's assessment of each firm's technical capabilities and resources, the extent of their experience and financial standing.
Initially, Contract 151 was for the supply of 96 motorised and 48 trailer carriages in a four-carriage formation, thus equivalent to 36 trains. The contract was estimated to be worth around S$200 million and included French, Canadian, Japanese, British, West German, Belgian, Swedish, Finnish, and local firms having pre-qualified for it.
In November 1983, MRTC announced it would exercise its option to combine the rolling stock requirements for the first and second phases of the MRT project into Contract 151. Thus, it would purchase 396 train carriages, having decided against running four-car trains but six-car trains instead for more flexibility when operating the system.
With the deadline for submission of bids set for January 1984, this modification was a pleasant surprise to the companies bidding for Contract 151, as it is now a bigger task than initially planned, with the contract now estimated to be worth around S$500 million instead of the original S$200 million.
Award of Contract 151: Electrical Multiple Unit Trains (Rolling Stock)
On 11 April 1984, MRTC announced it had awarded Contract 151 for the design and building of 66 trains of six carriages each for the first and second phases of the MRT project to the Japanese consortium led by Kawasaki Heavy Industries, Ltd., comprising Nippon Sharyo, Ltd., The Kinki Sharyo Co., Ltd., and Tokyu Car Co., Ltd.
Touted by the media to be a 'glamour' contract, valued competitively at S$581.5 million, the Kawasaki Heavy Industries consortium beat the joint venture between British's Metro-Cammell (acquired by Alstom) and Singapore Automotive Engineering, and the partnership between Sweden's ASEA (succeeded as ABB) and Sembawang Shipyard.
The Japanese consortium would also supply S$20.9 million worth of spares over ten years and have given a strong undertaking to provide training for 200-300 key MRTC personnel, covering all rolling stock aspects, including engineering design, parts fabrication and car body assembly, quality assurance and control, and maintenance.
Kawasaki Heavy Industries would lead the manufacturing of C151 trains at their rolling stock manufacturing plant in Kobe, Japan. MRTC appointed National Iron and Steel Mills as its sub-contractor as the consortium shortlisted without a local partner. The former national shipping line Neptune Orient Lines would ship the trains to Singapore.
The C151 trains would be powered using the 750-volt direct-current third rail system and had thyristors to control the propulsion system for smoother passenger rides and greater energy efficiency. It had a regenerative braking system that fed electrical energy back into the power system, reducing overall energy consumption.
In July 1984, local media reported that Kawasaki Heavy Industries would supply a life-sized mock-up of the C151 carriage to be displayed at the National Exhibition at the World Trade Centre (now HarbourFront Centre). The S$500 million mock-up arrived in Singapore in October 1984 and was opened to the public in November of that year.
The MRTC management said it would utilise the mock-up C151 carriage to receive public feedback on the train's design, including the various seating arrangements. The 23-metre by 3.2-metre wide mock-up train carriage, fabricated in steel and weighed around 19 tonnes, took 15 weeks to build at Kawasaki's Kobe factory.
Following dialogue and feedback sessions conducted by MRTC, with the help of the mock-up C151 train carriage, MRTC announced in October 1985 that the C151 trains would use hard and contoured plastic seats instead of cushioned or steel ones and would be placed lengthwise along the sides of the carriage to facilitate boarding and alighting.
Arrival in Singapore and Testing & Commissioning Works
The first two C151 trains arrived in Singapore at the Tanjong Pagar Container Terminal on 27 May 1986. They were transported on trailers to the Bishan train depot for testing & commissioning works before they entered passenger service the following year.
The media reported on 8 July 1986 that the C151 train would commence its first official train test run at the Bishan train depot. A ceremonial trial run of the C151 train was conducted that day comprising 300 guests, including then-Minister for Communications and Information Dr Yeo Ning Hong, with a ribbon-cutting ceremony.
The first C151 trains entered passenger service on 7 November 1987, coinciding with the opening of Singapore's Mass Rapid Transit system and the first five stations of the North-South Line (NSL), following a launching ceremony officiated by then-Second Deputy Prime Minister Ong Teng Cheong and Dr Yeo Ning Hong.
Refurbishment and Upgrading
Voice Synthesisers
In early 1996, the C151 trains were fitted with Voice Synthesisers developed in-house by SMRT Trains, replacing manual announcements of stations made by train captains. The system emits clear and precise announcements, such as station calls and directions on changing trains at MRT interchanges. This comes after prototypes and early iterations of an automatic train-borne message announcement system were unveiled by SMRT Trains between 1990 and 1992.
Noise-Damped Wheels
From 1994 to 2000, the C151 trains were fitted with Noise-Damped Wheels following feedback from residents living near MRT tracks of rising noise levels from the C151 trains. The German-made wheels were fitted on all C151 trains at a cost of S$5.4 million and came with special absorbers that dampen vibrations on the wheel.
Mid-Life Refurbishment Programme
In 2004, SMRT said the C151 trains had reached mid-life and were due for an upgrade. It appointed Korea's Rotem Co. of the Hyundai Motor Group, together with Japan's Mitsui & Co., Ltd., and local firms RM Transit Technology Pte. Ltd. and dU LexBuild International Pte. Ltd. for a comprehensive mid-life refurbishment exercise. The C151 trains would be given face-lifts – aesthetic interiors with customer-friendly features – and equipment upgrades as well as service, operational, and safety improvements.
The 2.5-year Mid-life Refurbishment Programme from 2006 to 2008 was valued at a cost of S$142.7 million. The first upgraded train re-entered passenger service on 5 November 2006, with the remaining C151 trains refurbished and upgraded by 2 January 2009.
SMRT Active Route Map Information System
In mid-2010, the C151 trains were installed with the SMRT Active Route Map Information System (STARiS), first announced in November 2008 and developed in-house by SMRT Trains, which includes a light-emitting diode (LED) dynamic route map above each train door and textual vacuum florescent displays (VFD).
Upgrading and Improvement Programme
From 2010 to 2013, these C151 trains were put through an Upgrading and Improvement programme. The upgrades included new floorings, a large wheelchair symbol at the wheelchair bay, as well as having its builder and refurbishment plates fitted up.
Thales Re-Signalling Project
Between 2014 and 2015, all C151 trains were upgraded to be equipped with the Thales SelTrac Communications-Based Train Control moving-block signalling system under the Re-Signalling Project of Contracts 1652A and 1652B, awarded by SMRT Trains and Land Transport Authority (LTA) on 1 February 2012.
Following the upgrade, two seats at both ends of the C151 train are replaced with a signalling box to house the new signalling equipment ‐ the Vehicle On-Board Controller (VOBC) ‐ configured in hot standby. The Vehicle On-Board Controller at the front is usually the active one, with the rear one in a passive state, providing redundancy should one end fail by seamlessly switching to the other available Vehicle On-Board Controller.
Permanent Magnet Synchronous Motor Re-Tractioning Programme
SMRT announced on 4 July 2013 that its subsidiary would replace the original gate turn-off (GTO) thyristors in a four-quadrant chopper control propulsion system of all C151 trains with the energy-efficient insulated-gate bipolar transistor with variable voltage variable frequency (IGBT-VVVF) Permanent Magnet Synchronous Motors (PMSM) from Toshiba Corporation. Japan Transport Engineering Company (J-TREC) worked with Toshiba for underfloor equipment layout and system design works and on-site staff coaching for equipment replacement works.
Two prototype C151 trains fitted with PMSM underwent depot tests between February and April 2015 and mainline testing in June and July 2015. The two prototype C151 trains with PMSM entered passenger service on the Changi Airport extension of the East-West Line (EWL) on 30 July 2015. In addition to lower noise levels of around 12 decibels, the power consumption of PMSM trains was lower, up to 39 per cent, compared to the C151 trains with the original motor. PMSM trains were also able to feed up to 20 per cent more energy back into the network through regenerative braking.
With the successful attainment of key performance indicators, the contract for the full-fleet rollout was then awarded in January 2016, with the remaining 64 C151 trains to receive PMSM motors by December 2019. Only six C151 trains received the PMSM upgrade, with the remaining 60 C151 trains continuing to use their original DC motors.
Replacement and Decommissioning of C151 trains
The end-of-life (EOL) upgrade and refurbishment programme for C151 trains was put on hold on 26 October 2016 as the LTA stated its intentions to call a tender to replace all 66 first-generation C151 trains. Contract R151: Trains for North-South / East-West Lines was called on 13 April 2017, with the contract valued at around S$827 million subsequently awarded to German-based Bombardier Transportation (acquired by Alstom) on 25 July 2018 for initially 66 new Alstom Movia R151 trains.
Train 045/046 was the first C151 train to retire from its approximately 33-year service on 22 June 2020. As of October 2024, 49 of 66 C151 trains remain in passenger service.
LTA would work with several public and private organisations to retain and repurpose several trains for educational, training, or recreational purposes, giving decommissioned trains a new lease of life. LTA called for Contract R151D: Disposal of Decommissioned Trains on 16 May 2019 and subsequently awarded it to Toyotron (Pte.) Limited on 16 December 2019 at a value of S$828 million for its services to dismantle, scrap, and dispose of the retired trains.
