Abstract: A trailer for particulates, especially for fracturing sand, but also for other materials, has a clam shell gate, which sealingly engages when closed preventing egress of particulates. The gate is attached to a hopper which has an exterior control mechanism thus avoiding wear and tear from particulates. The hopper is an inverted pyramid with downward and inward inclined walls below the trailer. The trailer itself has a cargo compartment with forward and rear sloping walls and upright side walls. The sloping walls of the trailer and the inclined walls of the hopper are inclined at about 38° to the horizontal, which is greater than the angle of repose of fracturing sand to allow complete or near complete discharge of fracturing sand.

Abstract: A trailer for particulates, especially for fracturing sand, but also for other materials, has a clam shell gate, which sealingly engages when closed preventing egress of particulates. The gate is attached to a hopper which has an exterior control mechanism thus avoiding wear and tear from particulates. The hopper is an inverted pyramid with downward and inward inclined walls below the trailer. The trailer itself has a cargo compartment with forward and rear sloping walls and upright side walls. The sloping walls of the trailer and the inclined walls of the hopper are inclined at about 38° to the horizontal, which is greater than the angle of repose of fracturing sand to allow complete or near complete discharge of fracturing sand.

Abstract: A conventional dump trailer includes discharge members or doors which are typically mounted beneath the trailer. The movement of the doors is controlled by a control device of the present invention having a position sensor which is mounted on the trailer and a sensor actuator mounted on the discharge member. The amount of movement of a door is automatically limited at a preselected position. The control device allows for the discharge member to be further moved to further positions.

Abstract: A conventional dump trailer includes discharge members or doors which are typically mounted beneath the trailer. The movement of the doors is controlled by a control device of the present invention having a position sensor which is mounted on the trailer and a sensor actuator mounted on the discharge member. The amount of movement of a door is automatically limited at a preselected position. The control device allows for the discharge member to be further moved to further positions.