Abstract: An apparatus for detecting an increase to a selected level of the height of a bed of particulate solids in a shuttle car for the transportation of particulate solids. The apparatus including a support member adapted to be rotatably supported through or on a wall of the shuttle car for rotation about its longitudinal axis with its first end inside the shuttle car and its second end outside the shuttle car, a relatively flat plate member positioned on the first end of the support member in a plane generally parallel to the longitudinal axis on the support member so that the plate member is biased to extend vertically downwardly from the support member and a level indicator operatively connected to the second end of the support member so that when the plate member is rotatably urged toward a horizontal position by the increased height of particulate solids an indication of such increased height is provided to the shuttle car operator.