Abstract: A hollow walled structure (22) includes a shell (36) having a wall defining an interior compartment (46). A first support, in the form of a baffle (48), is disposed within the interior compartment (46) and engages the shell (36) at two locations (52, 54). A second support, in the form of a post (83), engages the shell (36) and extends through the interior compartment (46) to intersect the baffle (48). The shell (36), baffle (48), and post (83) are formed concurrently from a thermoplastic material by a rotational molding process. The rotational molding process can entail operations of pre-heating interior portions of the mold, delivering heat to the interior portions of the mold, and/or filling the mold with excess thermoplastic material prior to preheating the mold. The rotationally molded structure (22) has sufficient strength to function as a tank for carrying a liquid (34) in a liquid transport apparatus (20).

Abstract: An apparatus (20) for cleaning a surface (22) includes a clean fluid tank (26) containing a cleaning fluid (46) and configured for delivery of the fluid (46) to the surface (22). The clean fluid tank (26) has a first outer surface (76). A waste fluid tank (30) is coupled with the clean fluid tank (26) and has a second outer surface (78). The second surface (78) abuts the first surface (76) to form a conduit (84) between the first and second surfaces (76, 78), the conduit (84) being in fluid communication with the waste fluid tank (30). Vacuum motors (94) and (108), in communication with the conduit (84), operate to vacuum waste fluid (164) and air (116) into the waste fluid tank (30). The air (116) is expelled from the waste fluid tank (30) via the conduit (84).