Alstom Metropolis C830
C830 trains at Kim Chuan Depot
Interior of the Alstom Metropolis C830 on the Circle line
In service	28 May 2009; 14 years ago (2009-05-28) – present
Manufacturer	Alstom
Built at	Valenciennes, France
Family name	Metropolis
Constructed	2006 – 2008
Entered service	28 May 2009; 14 years ago (2009-05-28)
Number built	120 Vehicles (40 Sets)
Number in service	120 Vehicles (40 Sets)
Formation	3 per trainset Mc1–T–Mc2
Fleet numbers	801 – 840
Capacity	931 passengers 148 seats
Operators	SMRT Trains Ltd (SMRT Corporation)
Depots	Kim Chuan
Lines served	CCL  Circle line
Specifications
Car body construction	Welded aluminium
Train length	70.1 m (229 ft 11+7⁄8 in)
Car length	23.65 m (77 ft 7+1⁄8 in) (Mc) 22.8 m (74 ft 9+5⁄8 in) (T)
Width	3.21 m (10 ft 6+3⁄8 in)
Height	3.68 m (12 ft 7⁄8 in)
Floor height	1,110 mm (43+3⁄4 in)
Doors	1,450 mm (57+1⁄8 in), 8 per car, 4 per side
Wheel diameter	850–775 mm (33.5–30.5 in)[1]
Wheelbase	2.5 m (8 ft 2 in)[1]
Maximum speed	90 km/h (56 mph) (design) 78 km/h (48 mph) (service)
Weight	120 t (120 long tons; 130 short tons) (unladen) 199 t (196 long tons; 219 short tons) (fully laden)
Axle load	16 t (16 long tons; 18 short tons)[1]
Traction system	Alstom ONIX IGBT–VVVF
Traction motors	8 × Alstom 4LCA 2138[2] 150 kW (200 hp) asynchronous 3-phase AC
Power output	1.2 MW (1,600 hp)
Acceleration	1.1 m/s2 (3.6 ft/s2)
Deceleration	1.3 m/s2 (4.3 ft/s2) (Emergency)
Electric system(s)	750 V DC third rail
Current collector(s)	Collector shoe
UIC classification	Bo′Bo′+2′2′+Bo′Bo′
Bogies	Alstom B25[1]
Braking system(s)	Regenerative and pneumatic
Safety system(s)	Alstom URBALIS 300 moving block CBTC ATC under ATO GoA 4 (UTO), with subsystems of ATP, Iconis ATS and Smartlock CBI[3][4]
Coupling system	Scharfenberg
Track gauge	1,435 mm (4 ft 8+1⁄2 in) standard gauge

The Alstom Metropolis C830 is the first generation of communication-based train control (CBTC) electric multiple unit rolling stock in operation on the Circle line of Singapore's Mass Rapid Transit (MRT) system since 2009. Alstom was contracted in 2000 (as part of turnkey contract Contract C830) by the Land Transport Authority (LTA) in Singapore to supply the trains for the Circle line.

Operational history and overview

Despite being similar to the fully underground North East line, the decision was made to power the three-car trains along the Circle line by third rail instead of overhead catenary. 40 trainsets of three cars each were purchased for the Circle line. For the train's tender, Alstom was awarded the contract on 28 December 2000, beating seven pre-qualified contractors.^[5]

The front of the train features an extra window cut into the emergency exit door unlike the C751A trains, giving passengers a view of the tunnel.^[6]

Driverless operation

The C830 is fully driverless under normal circumstances, using CBTC which does not require traditional "fixed-block track circuits" for determining train position. Instead, they rely on "continuous two-way digital communication" between each controlled train and a wayside control center, which may control an area of a railway line, a complete line, or a group of lines. Recent studies consistently show that CBTC systems reduce life-cycle costs for the overall rail property and enhance operational flexibility and control.^[7]

Train formation

The coupling configuration of a C830 in revenue service is Mc1–T–Mc2.

The car numbers of the trains range from 801x to 840x, where x depends on the carriage type. Individual cars are assigned a four-digit serial number by the rail operator SMRT Trains. A complete three-car trainset consists of one trailer (T) and two driving motor (Mc) cars permanently coupled together. For example, set 801 consists of carriages 8011, 8012 and 8013.

• The first digit is always an 8.
• The second and third digits identify the set number.
• The fourth digit identifies the car number, where the first car has a 1, the second has a 2 and the third has a 3.
• Alstom built sets 801 – 840.