Siemens SD660

Siemens SD660 (Types 2 and 3)
A train of SD660s on the Steel Bridge in Portland, Oregon
Interior of an SD660
Manufacturer	Siemens
Built at	Sacramento, California
Constructed	1996–2005
Entered service	1997
Number built	79
Number in service	79
Successor	Siemens S70/S700
Fleet numbers	Type 2: 201–252 Type 3: 301–327
Operators	TriMet
Specifications
Car length	91.93 ft (28.02 m) over couplers
Width	8.71 ft (2.65 m)
Height	13 ft (4.0 m)
Floor height	High floor section: 3.22 ft (980 mm) Low floor section: 1.18 ft (360 mm)
Low-floor	70%
Entry	Level
Doors	8 per car (4 per side)
Articulated sections	3
Wheelbase	5.90 ft (1,800 mm)
Maximum speed	55 mph (89 km/h)
Weight	108,000 lb (49 t)
Traction system	Siemens IGBT–VVVF[1]
Traction motors	4 × Siemens 175 kW (235 hp) 3-phase AC induction motor
Power output	700 kW (940 hp)
Acceleration	3 mph/s (1.3 m/s2)
Deceleration	3 mph/s (1.3 m/s2) (service) 5 mph/s (2.2 m/s2) (emergency)
Electric system(s)	Overhead line, 750 V DC
Current collector(s)	Pantograph
UIC classification	Bo′+2′+Bo′
AAR wheel arrangement	B-2-B
Minimum turning radius	82.02 ft (25.00 m) (horizontal) 820 ft (250 m) (crest vertical) 1,150 ft (350 m) (sag vertical)
Coupling system	Scharfenberg
Multiple working	Within type With Bombardier Type 1 [2][3]
Track gauge	4 ft 8+1⁄2 in (1,435 mm) standard gauge

The Siemens SD660, originally known as the Siemens SD600,^[4] is a double-articulated, 70%-low-floor light rail vehicle (LRV) manufactured by Siemens Transportation Systems. It was the first low-floor light rail vehicle to be used in the United States.^[5][6] It first entered service in 1997 with its only operator, TriMet, on the MAX light rail system in Portland, Oregon, United States.