Implementations of slip linkages are shown and described, including two-part and three-part implementations. Implementations of these linkages provide connections between elements with at least one translation degree of freedom, sometimes referred to as a prismatic joint or slider or telescopic joint. Such implementations may be utilized in connection with covers for roll-off containers or dumpsters, such as retractable container covers.

A cover drive system comprises a flexible cover or tarp, a front cover arm, a rear cover arm, and a towel bar. The front cover arm includes first and second sections connected together by a flex member. A drive system is attached to the front cover arm and is configured to deploy and retract a tarp cover. The drive system includes a transmission with a disconnect that permits manual operation of the tarp covering system without removing the drive motor. The rear cover arm includes a rear flex member that permits normal operation of a rear trailer end panel when configured as a hinged tailgate or door. The tarp is supported by a plurality of bows that can accommodate relative movement of trailer side walls during operation. In certain embodiments, the rear cover arm may be substituted with a tarp tensioner. The tarp tensioner includes a tensioning assist spring and block-and-tackle to assist in retracting the tarp from a deployed state.

Methods and apparatuses for shipping of fabricated rectangular wooden modules used for construction of a wood frame structure and for shipping of other bulky items are described. In particular, the disclosure features a modified shipping container for shipping the fabricated rectangular wooden modules and methods of loading, transporting, and unloading the fabricated rectangular wooden modules. The modified shipping container features a removable header system and a removable cover. The fabricated rectangular wooden modules include a module length axis, a module width axis, a bounded wood perimeter, and joists or rafters oriented perpendicularly to the module length axis, and are stacked as cargo in the interior of the container such that joists or rafters of the fabricated rectangular wooden modules are substantially vertical and the length axes of the modules are substantially parallel to a length axis of the container.

Methods and apparatuses for shipping of fabricated rectangular wooden modules used for construction of a wood frame structure and for shipping of other bulky items are described. In particular, the disclosure features a modified shipping container for shipping the fabricated rectangular wooden modules and methods of loading, transporting, and unloading the fabricated rectangular wooden modules. The modified shipping container features a removable header system and a removable cover. The fabricated rectangular wooden modules include a module length axis, a module width axis, a bounded wood perimeter, and joists or rafters oriented perpendicularly to the module length axis, and are stacked as cargo in the interior of the container such that joists or rafters of the fabricated rectangular wooden modules are substantially vertical and the length axes of the modules are substantially parallel to a length axis of the container.

The disclosure provides an article of manufacture that includes a rectangular horizontal member, a vertical member bisecting a length of the horizontal member and forming a T-junction at the horizontal member, first and second sloped members spanning from a top of the vertical member to opposing ends of the horizontal member, and first and second support members spanning from the T-junction between the vertical member and horizontal member to work points on an underside of each of the first and second sloped members. The article of manufacture can be assembled on the ground at a construction site from prefabricated units shipped together in parallel planar orientation in a shipping container to provide a truss unit for forming the roof of a structure.