A storage container system includes a storage container having a frustoconical roof defining a central opening and a lid assembly mounted to the roof of the storage container. The lid assembly includes a rail guide member mounted to the roof of the storage container and oriented such that a center longitudinal axis of the rail guide member has a same pitch as the roof and a lid rotatably coupled to the rail guide member and configured to slide along the rail guide member between open and closed positions over the opening, where when the lid is in an open position, an upper surface of the lid has a same pitch as the roof.

A transportable container apparatus includes an elongate container having a central axis and a base attached to a bottom end of the container. The container and base are substantially symmetrical about the central axis and the container is oriented substantially vertically with the base resting on a ground surface when in a working position. The container having an upper container section with upper walls substantially parallel to the central axis and a lower container section with lower walls substantially parallel to the central axis. The upper container section includes a sloping hopper at a bottom thereof to direct granular material into the lower container section. A floor of the container is sloped toward an outlet port defined in a ported wall of the lower container section such that granular material stored in the container slides down the floor to the outlet port.

A hopper has a gate pivotable to open and close the lower opening of a hopper body, wherein opposing side parts more spaced apart than a width of the body are extending from the gate, and the opposing side parts of the gate are externally fitted pivotably to fulcrum shafts protruding from outer side surfaces of the hopper body. The hopper further includes regulating members interposed between the outer side surfaces of the body and the opposing side parts of the gate. The regulating members are configured to regulate movements of the gate in pivotal directions thereof and are detachably engaged with the fulcrum shafts circumferentially around the fulcrum shafts.