Abstract: A maintenance vehicle and associated method for measuring and correcting the level of a railroad track in a single pass. An instrument carriage, or frog, is towed by and in fixed relationship to the maintenance vehicle. The frog carries at least one inclinometer to measure at least one of longitudinal level and crossfall. As the vehicle periodically stops to work the track e.g. tamping or stoneblowing), the inclinometers are provided with the settling time necessary for accurate readings. In an additionally disclosed method, the track is measured and modeled prior to working using a primary measurement system and is then measured and modeled a second time while the track is worked using the frog.

Abstract: An apparatus and method is provided for measuring the wear in the cross-sectional profile of a railroad rail. A carriage is adapted for travel along the length of the rail and includes means for moving transversely with respect to its direction of travel in response to wear in the railhead of the rail. Distance sensors fixedly mounted to the carriage sense the changes in distances from the carriage to the rail as the carriage moves in a direction transverse to the direction of travel. The sensors relate the changes in these distances to wear in the top and gauge sides of the railhead.

Abstract: A track inspection car supported on railroad track by flanged wheels mounted on a truck, and having means for engaging a tractor-truck at one end and wheels with highway tires at the other. The wheels are relatively vertically displaceable by selectively inflating pneumatic springs for converting the car from on-track operation to an off-track trailer-truck configuration. A pair of ultrasonic sensor probes are mounted on the wheel truck coupled to a computer in the car. The car also includes an on-track driving motor, a driver station, a computer operators station, an observer's station, and a water supply for creating a fluid acoustical coupling between the sensors and the rails.

Abstract: A railroad track tamper control system of the type wherein the grade rail is jacked relative to a reference line, the level rail is cross leveled to the grade rail before tamping, and the tamper frame is relatively independent of the jacking; in which a cross level sensor is mounted on the main tamper frame to free it from jacking vibrations and vertical position sensors measure the jacked elevations of both the grade and level rails relative to the tamper frame. The system cross levels the level rail by comparing the elevation of the grade and level rails relative to the tamper frame and adjusting that comparison by any out-of-cross level of the frame sensed by the cross level sensor.