21. Each elevator shall be operated by two (2) plungers. Plungers shall be twenty (20) inches diameter and shall be constructed from steel pipe or tubing with a three-fourth (3/4") inch thick wall. The outside of the plungers shall be accurately turned and polished. Where joints are necessary, they shall be made by a closely fitting internal sleeve, screwed into each piece of tubing, and made tight with hydraulic cement. The sleeve shall be of sufficient length to develop the full strength of the tubing.
22. At the head of each plunger there shall be attached a cast steel platten, for attaching the structural steel platform members. Plattens shall be black open-hearth steel castings, free from defects and shall be carefully annealed before machining.
23. To the bottom of each plunger there shall be attached a cast stool plug, with a projecting flange to provide a positive stop at the top limit of travel.
24. Each cylinder shall be built of twenty-four (24”) inch 0.D. steel pipe with a welded head at the lower end. The upper cylinder head and stuffing box shall be of close grained gray cast iron, attached to the cylinder by a belting flange, set flush with the elevator pit floor. The complete cylinder assembly shall be tested at four hundred (400) pounds water pressure and all leaks corrected before installation, and the pipe shall receive two (2) coats of asphaltum, applied hot.
25. Plunger packing and Control Piping:
Plunger packing shall be of an approved non-compressing type and arranged for easy replacement. Connections to control valves shall be five (5) inch extra strong pipe with extra heavy two hundred and fifty (250) pound fittings.
26. Location and Installation of Cylinder Assemblies:
Cylinder assemblies shall be accurately located in the holes for their reception, and the space around then closely pocked with sand to within eighteen inches (18") of the top. The remaining space shall then be filled with grout.
27. Platform Frames:
Each platform shall be supported on a structural steel frame, extending the full length of the platform. The floor system shall consist of suitable beams framed to girders. The framing of the floor beams shall be such that full provision shall be made for the revolving stage, as hereinafter described, and sufficient headers shall be used to develop the lateral stiffness of the girders. All connections other than those of the floor system shall be hot riveted with rivets not less than seven-eighth (7/8") inch diameter.
28. Wood Flooring:
Wood nailing strips shall be attached to the floor beams for attaching wood flooring.
29. Floor shall be first grade hard maple, fifty-three thirty-seconds (53/32") inches by two and one-quarter (2-1/4") inches, dressed and matched and end matched T. & G., in minimum lengths of four (4'-0") feet, and to meet the requirements of the Maple Flooring Manufacturers Association. The platform shall be designed to support
a uniformly distributed live load of one-hundred (100) pounds per square foot, and under the normal working load of twenty-five (25) pounds per square foot, the maximum deflection shall not exceed one-eighth (1/8") inch.
30. All steel work shall receive one (1) shop coat of red lead paint.
31. The elevator contractor shall furnish a sheet metal guard five (5') feet deep around the underside of each elevator, and shaped to form a beveled toe guard at the point where it joins the platform. The canvas masking drop shall be attached to the lower edge of the sheet
metal extending eight (8') feet below to completely mask in the openings when the elevators are at high level; also to have telescope-braced brackets back of canvas to keep the canvas rigid, this applies to both sides and both ends of the elevators.