Apparatus enabling access to the interior surfaces bounding a large spaced comprises a pole adapted to extend vertically through the height of the space with its lower end located at the base of the space, at least one boom structure connected with said pole, a working platform connected to the end of said boom structure remote from said pole and the height of said boom structure is adjustable relative to said pole.
This is a continuation of application Ser. No. 826,121 filed Aug. 19, 1977, now abandoned, which in turn is a continuation of Ser. No. 623,632, filed Oct. 20, 1975 now abandoned.
In a steel truss an upper longitudinal beam and a lower longitudinal beam are interconnected at their respective ends by vertical posts, and between their ends by a plurality of mutually intersecting, obliquely extending struts and ties only. Each end post is composed of two parts of substantially equal lengths, which are interconnectable end to end, and each strut and tie is composed of two parts, which are interconnectable at the intersection between them, whereby the truss may be factory-made in sections of moderate size for convenient transportation to the building site, where the assembly of the same requires only a minimum of work.
A crane is comprised a foundation, a supporting pole elongating vertically from the foundation, an arm capable of rotatably moving on a plane parallel with the supporting pole, and a winding drum mounted at the tip end portion of the arm, the arm consisting of two arms elongating in parallel with each other, the drum being mounted between two arms. The crane is installed on the rooftop of a building or the like and capable of effectively pulling up an object from a narrow road onto a narrow rooftop and setting it up on a rooftop.
