AMTK10003

Acela Inspection Car

Note- most pictures are links to larger images Amtrak's Acela high speed trainset is scheduled for revenue speeds of up to 150 miles per hour. In order to maintain safety standards, the Federal Railroad administration (FRA) mandated that passenger railroad must be tested periodically, using like equipment. Since 1983, when Amtrak introduced the AMTK10002 inspection car, it has strived for ultimate perfection in track geometry inspection and analysis. In conjunction with the Acela trainset equipment in 2000, Amtrak introduced it's newest in the testing fleet, the AMTK10003.

The main component of the geometry testing system is the instrumented beam, suspended just above the rails. On either side are infrared laser camera boxes (1) that analyze the position of the rails as the car moves. Between them are housed lateral and vertical accelerometers and a pair of optical gyros in the "cas package"(2). The gyros are state-of-the-art design of the latest in space age optical technology. Below that is the Automatic Location Sensor (3) or ALD sensor.
The placement of the beam is apparent noting the three huge brake rotors (4) and the wheels (5) directly behind the instrumentation. Another view

Two small windows can be seen under the laser camera boxes, made by KLD Labs. One, at right angles to the rail, allows the infrared laser source to "paint" a line on the rail. The diagonal placed window is for the special camera that is tuned to see only the infrared light of the laser source. Complex algorithms calculate exact rail placement under each box as the train rolls along.

The ALD sensor is an inductive solid state device that senses masses of metal in the railbed and allows exact referencing to heavy metal objects such as switch apparatus and other railroad fixtures. On the end of one axle is a digital encoder that sends thousands of pulses per revolution of the wheel to the computers to determine exactly how far the car has gone and triggers data sampling exactly once every foot, up to the train's top speed of 150 MPH and beyond.

The car is dedicated totally to the job of testing. It is divided into three areas by major function. The largest is the instrumentation and testing area, wide open and covering fully half the car. Here technicians edit and publish data as it comes off the car's systems. Railroad maintenance supervisors learn the condition of their railroad and can review data that shows areas on their territory needing repair.

The system's computers are housed in two 6 foot high industrial component racks. All but one of the computers are dual processor pentiumII machines. Four use a windows operating system while three use QNX, a real time based unix-like operating system used for data acquisition and also Global Positioning Satellite tracking of the car. The tall racks also house analog to digital signal conditioning equipment and the controls for the KLD lasers.

The car is a self contained work platform with a full workshop area for field repairs. Spare parts and adequate tooling are maintained on board to permit almost any repair. the onboard crew of two or three technicians maintain and calibrate the vehicle and perform routine repairs themselves.

Since technicians can be expected to put in long hours with no ability to leave the car, an office and eating or lounge area is also aboard. The employees on board can grab a quick bite while finishing off necessary paperwork, and can relax in anticipation of the next test.
If you are interested in the equipment used for geometry testing on the 10003, see.....