Siemens SD-400
4101–4155
Built 1985–87, refurbished 2005–06 and renumbered 4201–4255
Car Specific Specifications
Manufacturer/Model: Siemens SD 400
Vehicle type: Double ended Articulated
Developed by:
Date in service:
Number of cars ordered: 55
Number of cars still in service (to date): 53
Number of trucks: 3, 2 powered, 1 dead
Number of axles: 6
Car Body
Manufacturer: Siemens Transportation Systems
Underframe: Low Alloy High Tensile Steel
Superstructure: Low Alloy High Tensile Steel
Interior Finish:
Floor: Rubber over Plywood
Steps:
Doors: Three High Level Doors and One Low Level Door per Side
Windows:
Seats: 62
Disabled Access: High Level Platforms / High Level Doors
Suspension, Propulsion, Braking
Trucks/Bogies:
Suspension: Rubber Chevron Springs (Primary), Air Spring System (Secondary)
Truck centers:
Wheels:28.34" new
Wheel base:
Track gauge: 62.5" (1,588 mm)
Motors: Dual DC-Chopper, Monomotor Two Motors per Car
Gear ratio:5.67:1 .
Gearbox: .
Slip/slide protection:
Service Brakes: Pneumatic Friction Brakes
Track Brakes:
Air compressor:
Traction Motor Rating: 205 kW (275 hp) (one hour rating, each motor)
Vehicle Capacity
Seated Load: 62
Design Load:62 seated, 108 standing
Crush Load:62 seated, 216 standing
Passenger Comfort
Heating: Baseboard
Air-conditioning: Sutrak HVAC, Compressor under car, condenser on top of car
Vehicle Dimensions
Length over couplers: 84 feet, 8 inches (25.81m)
Length over body ends:
Width: 8 feet, 9.6 inches (2.65m)
Height (rail to roof):
Height (rail to floor):
Pantograph operating range:
Empty weight per car: 85,800 lbs. (39,000 Kg)
Interior headroom: 6 feet, 9 inches
Interior width (articulated section):
Doorway width (minimum):
Doorway height:
Step height: None (High Level Platforms / High Level Doors)
Vehicle Performance
Maximum design speed: 50 mph, governed to 30
Maximum operating speed:30
Service acceleration on level tangent track: 3.0 mphps
Service braking on level tangent track: 3.7 mphps
Emergency braking on level tangent track:6 mphps
Electrical and Control Systems
Power Supply: 650 Volts DC
Low voltage power supply: 16.5 volts
Interior Lights: Flourescent
Motor Control: DC Chopper Control ( 2 Separate, 1 Filter )
Pittsburgh was the fourth city in North America to acquire Siemens equipment, following the successful deployment of the proven U2 design in Edmonton, Calgary, and of course, San Diego. Pittsburgh's U3 LRVs were later designated model SD400 by Siemens. The SD ("Siemens Duewag") nomenclature has replaced the U designation on subsequent North American car orders. Also, St. Louis, Missouri's Siemens LRVs also are classified as SD400s. They are the lone cities to use this particular codename.
Port Authority's chopper-controlled U3 cars are some six feet longer and 16,500+ pounds heavier than their U2 predecessors. The cars' monomotor trucks feature 275 hp motors to tackle Pittsburgh's drastic topography. Uneven wheel and gear wear have, not surprisingly, been a major problem, but Pittsburgh's monomotor cars are not unique in this regard.
The cars have three floor-level,double-stream doors per side, and one low-level single- stream door opposite the operator's area at either end. This somewhat unconventional arrangement was necessitated by Pittsburgh's mix of high-platform stations and low-platform stops. Fares are collected by attendants at some major stations, mostly during peak periods, but on-board fare collection still prevails. For this reason, fareboxes are stationed behind the drivers' semi-enclosed cabs, and operators must turn around to issue transfers and monitor passengers passing the farebox.
