Patented platforms for temporary installation within a boiler-furnace for generating electricity to facilitate manual inspection and (if necessary) repair of the furnace and its parts. The apparatus includes a generally horizontal platform upon which workers stand, and cables for raising and lowering the platform. The platform is manually assembled inside the boiler from relatively small construction elements, each of which is small enough to be inserted through a small access opening in the pressure vessel. A relatively large platform is constructed in a vertical mode, and subsequently rotated to its horizontal working orientation. In the preferred construction, adjustment of elevation of the platform is accomplished with an electro-hydraulic system which uses hydraulic fluid that is pressurized on the roof of the pressure vessel and used by winches mounted on or near the platform.
After the vessel has been suitably inspected (and repaired as necessary), the platform is removed in the reverse order in which it was installed: personnel are removed from the platform, it is tilted back to a vertical orientation and segments are then progressively removed from the lowermost edge until all of the platform is disassembled and the construction elements have been individually removed through the small access opening. The cables are then withdrawn through the roof of the vessel.