Abstract: A method and apparatus for operating a train positioner for moving one or more railroad cars of a unit train are disclosed. The positioner is engaged with the train while the positioner is stopped at an initial location. The positioner is moved and the train is accelerated to a constant speed. The energy expended by the positioner in accelerating the train to the constant speed is determined and apparent mass of the train is calculated from this energy. From the apparent mass of the train, a maximum force to which the positioner should be subjected, and a deceleration rate, a deceleration point adequate to stop the train by a predetermined, final location is calculated. The positioner is decelerated beginning at the deceleration point and at the deceleration rate until the train is stopped by a final location. In a preferred embodiment, the deceleration rate is also calculated from the apparent mass of the train and the maximum force to which the positioner should be subjected.

Abstract: An extensible and retractable telescopic chute for delivery of bulk materials includes a plurality of nestable chute segments, namely, an uppermost segment adapted to be attached to the discharge end of a bulk material handling machine, a lowermost chute segment and a plurality of intermediate chute segments therebetween. A yoke member surrounds the lowermost chute segment and is attached thereto. A pair of sheave support posts upwardly extend on opposed sides of the yoke member. Each of the posts carry a rotatable sheave wheel which are respectively adapted to operably engage a wire rope of the hoist mechanism of the material handling machine. The yoke member bears the loading weight of the nested chute segments as the telescopic chute is retracted so as to avoid sidewall deformation of the lowermost segment. The vertically extending sheave support posts locate the sheave wheels well above a center of gravity of the nested chute segments to stabilize the chute assembly above a vertical axis.