Abstract: A dragline comprising a main housing including a generally horizontal platform, a boom extending forwardly from the main housing, a bucket suspended from the boom, a winding drum mounted on the platform for rotation about a generally horizontal axis, a fairlead mechanism mounted on the platform forward of the drum, the fairlead mechanism including an upper sheave mounted on a generally C-shaped upper bracket for rotation relative thereto about a generally horizontal upper axis, the upper bracket opening rearwardly and being mounted on the platform for pivotal movement about a generally vertical axis, and a lower sheave mounted on a generally C-shaped lower bracket for rotation relative thereto about a generally horizontal lower axis rearward and below the upper axis, the lower bracket being substantially identical to the upper bracket, opening forwardly and being mounted on the platform for pivotal movement about the generally vertical axis, such that the vertical axis extends between the upper and lower shea

Abstract: A gear drive including an input gear having alternative first and second positions and which is selectively locatable at one of the first and second positions. The input gear includes a circumferential surface having a preselected first plurality of teeth when the input gear is located at the first position and a preselected second plurality of teeth larger than the first plurality of teeth when the input gear is located at the second position. A power source is connected to the input gear for rotating the input gear at a first rotational speed when the power source is connected to the input gear at the first position and at a slower second rotational speed when the power source is connected to the input gear at the second position. Output gears engage the input gear for receiving circumferential drive from the input gear which is at substantially the same velocity with the input gear located at both the first and second positions.

Abstract: An elevated track network guides self-propelled guided vehicles (with containers thereon) from an entry location where objects enter the system, to a storage zone defined by sets of compartmentalized storage racks wherein containers filled with objects are temporarily stored, and from thence to an exit location where retrieved objects leave the system. Each set of storage racks comprise four racks and two aisles, with two of the racks arranged back-to-back between the aisles and the other two racks on opposite sides of the aisles. Each storage rack comprises storage compartments arranged in horizontal rows and vertical columns. A track in the track network extends through and along an intermediate row in one of the back-to-back racks (pre-empting the compartments in that row). Each aisle accommodates a self-propelled aisle crane which services the racks on both sides of the aisle.