Furnace maintenance platform

A furnace having four enclosing walls and a roof, with steam generating tubes lining the walls, steam superheating tubes extending down into the furnace from the roof, a plurality of openings extending along opposite walls of the furnace at an elevation subjacent to the superheating tubes, a plurality of adjacent first beams, one each of said first beams having an inner end and an outer end and extending into the furnace through each one of the openings from opposing sides, the outer end of each first beam being supported outside of the furnace, a plurality of cables extending down from the furnace roof, the inner end of each first beam being supported by one of the cables, each cable containing a turnbuckle close to the first beams, which turnbuckles can be adjusted so as to support the first beams in a relative horizontal position, second beams extending perpendicularly between the respective inner ends of the first beams on an opposing side, and being secured to the upper surfaces thereof, so as to tie all of the first beam inner ends together on an opposing side, and boards extending between each adjacent first beams, and between each of the second beams across from each other, so that a platform is formed which covers substantially the entire cross-section of the furnace.