C151

Kawasaki Heavy Industries (KHI) C151
A refurbished Kawasaki C151 train Interior of a Kawasaki C151's center motor car before refurbishment Interior of a refurbished Kawasaki C151's center motor car Inside the front driving car of a refurbished C151 train The interior of a refurbished C151 motor car
In service	7 November 1987 – present
Manufacturer	(with Nippon Sharyo, Tokyu Car, and Kinki Sharyo)
Built at	Kobe, Japan
Constructed	1986 – 1989
Refurbishment	Hyundai Rotem (with Mitsui, dU LexBuild and RM Transit Technology) 2006 – 2008
Number built	396 vehicles (passenger service) 4 vehicles (money train)
Number in service	396 vehicles (66 trainsets)
Number preserved	4 vehicles (money train)
Formation	6 cars per trainset DT–M1–M2–M2–M1–DT
Capacity	1920 passengers 372 seats (initial design) 208 seats (after refurbishment)
Operator(s)	SMRT Trains (SMRT Corporation)
Depot(s)	Bishan, Changi, Tuas, Ulu Pandan and East Coast(future)
Line(s) served	North South Line and East West Line
Specifications
Car body construction	Aluminium-alloy double-skinned construction
Car length	23.65 m (77.6 ft) (DT) 22.8 m (75 ft) (M1/M2)
Width	3,200 mm (130 in)
Height	3,690 mm (145 in)
Doors	1,450 mm (57 1⁄16 in), 8 per car
Maximum speed	90 km/h (56 mph) (design) 80 km/h (50 mph) (service)
Weight	217 t (214 long tons; 239 short tons) (DT) 38.3 t (37.7 long tons; 42.2 short tons) (M1) 38.4 t (37.8 long tons; 42.3 short tons) (M2)
Traction system	Original: 4-quadrant/GTO chopper control (Mitsubishi Electric) Upgraded: IGBT-VVVF (Toshiba, 055/056, 065/066, 109/110 and 131/132 only)
Traction motors	Original: Two-phase DC shunt-wound motor (Mitsubishi Electric) 145 kW (194 hp) 375 V 430 A 2050 rpm (1 hour rating) Upgraded: Permanent Magnet Synchronous Motor (Toshiba, 055/056, 065/066, 109/110 and 131/132 only)
Power output	2.32 MW (3,110 hp)
Transmission	Westinghouse-Natal (WN) drive; Gear ratio: 6.57 : 1
Acceleration	1.0 m/s2
Deceleration	1.0 m/s2 (service) 1.3 m/s2 (emergency)
Electric system(s)	750 V DC third rail
Current collection method	Collector Shoe
Bogies	H-frame Bolsterless (Siemens)
Braking system(s)	Electro-pneumatic, regenerative and rheostatic (Westinghouse Brake and Signal)
Safety system(s)	Current: Westinghouse Brake and Signal Company Ltd fixed block ATC with subsystems of ATO GOA 2 (STO), ATP and ATS Future: Thales SelTrac® Moving Block CBTC ATC with subsystems of ATO GOA 3 (DTO), ATP, NetTrac ATS, CBI
Coupling system	Scharfenberg
Track gauge	1,435 mm (4 ft 8 1⁄2 in)

The Kawasaki Heavy Industries C151, sometimes abbreviated to C151 or KHI C151 is the first generation Electric multiple unit rolling stock in operation on the North South and East West Lines of Singapore's Mass Rapid Transit (MRT) system. These are the oldest trains built for the system; they were introduced in 1987 and are still in operation. Sixty-six trainsets consisting of six cars each and a single money trainset consisting of four cars were purchased. These trains are operated by SMRT Trains.

These trains were manufactured from 1986 to 1989 in batches by a Japanese consortium consisting of , Nippon Sharyo, Tokyu Car Corp and Kinki Sharyo following a round of intense competitive bidding by rolling stock manufacturers from around the world. No visible differences can be found in any of these batches, which were built to agreed specifications.

The trains underwent a two-year mid-life interior refurbishment programme by Hyundai Rotem. After major train disruptions on 15 and 17 December 2011, further plans to upgrade its mechanical components to increase its reliability were made. The first trainset to receive this upgrade, which included a replacement traction system, entered service in July 2015.

In spite of SMRT having already purchased the traction system, plans were put on hold when LTA acquired all of SMRT rail assets in August 2016 under the New Rail Financing Framework. Due to concerns and issues with older trains, it was announced will be calling a tender to replace the 66 Kawasaki Heavy Industries C151 trains that have been operating for the last 29 years with brand new ones. On 13 April 2017, contract R151 was published for the replacement of these first-generation trains.

With construction of the Mass Rapid Transit system underway in 1983, Contract 151 called for the procurement of rolling stock—150 cars in Phase One and an option for 246 cars in Phase Two. In what Financial Times described as "a time when manufacturers were begging for orders" for the global rolling stock market, competition for the contract was intense. At least eight companies from around the world submitted bids for what they had nicknamed the "Big One". Bidders included Metro-Cammell with Singapore Automotive Engineering, Kawasaki Heavy Industries with three Japanese manufacturers, MAN AG with AEG, Siemens and Brown, Boveri & Cie, Francorail with Alsthom-Alantique, SOFRETU and Singapore Shipbuilding and Engineering, ASEA with Sembawang Shipyard, and a Bombardier Transportation-led consortium with Hawker Siddeley Canada and Brown Boveri Canada.