Section 7.272. Shaftway construction  


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  • (a) New shaftways—general. Shaftways of freight elevators erected in buildings over two stories in height shall be constructed of fire-resistive material, except when overhead loads are carried on a steel or angle iron tower, or by the structural parts of the building, in which case fire-resistive curtain walls may be provided in lieu of such fire-resistive material. There shall be no opening except for necessary fire-resistive doors, windows or skylights. When basement machines are installed, and the openings in the shaftway walls for cables or sheaves exceed ten square feet, the machine rooms shall be constructed of fire-resistive material. When fire-resistive construction is not required the shaftways of freight elevators shall be enclosed with a solid or substantial grille or latticework on all sides from floor to ceiling, except at landing gates and doors. The open spaces in such grille or latticework shall be such that a ball two inches in diamtere will not pass, and the wire or material used shall not be less than No. 10 standard steel wire gauge (0.135 inch). When bordering on counterweight runways, or when moving parts are within four inches of such enclosures, the open spaces shall be such that a ball 3/8 inch in diameter will not pass. Machine room doors shall be locked at all times, except when repairs are being made or when the machinery is being inspected or serviced. Oil-electric pump units installed in basement areas will not require a machine room provided the controller is enclosed in a fire-resistive cabinet equipped with a lock and the pumping unit is properly guarded.

    (b) Existing shaftways—general. The shaftways of freight elevators, when not completely enclosed with fire-resistive or other construction, shall be encased with a solid or wire mesh enclosure to a height of at least 6 feet from the floor at all landings. If wire screen is used it shall not be greater than two inch mesh and of not less than No. 10 standard steel wire gauge 0.135 inch in diameter, When moving parts are within 4 inches of the shaftway enclosures, such enclosures shall be covered with wire screen of not more than 3/8 inch mesh, to a height of not less than 6 feet from the floor and to a distance of at least 6 inches to the right and left of such moving parts. When shaftways are equipped with automatic horizontal hatch covers, standard railings and toeboards may be substituted for the enclosure specified in this subsection, if they are located at least 12 inches from the line of the shaftway. When in the judgment of the Department, fire-resistive construction is necessary for the protection of the occupants of buildings or employes, such construction shall be provided.

    (c) Grillework and enclosing walls. The grillework and enclosing walls of freight elevator shaftways shall be flush with all floor openings at landings, as well as with the line of the elevator shaftway at each side; except that approved landing gates may be operated inside of the shaftway or enclosure.

    (d) Windows into shaftways. Windows in the outside walls of buildings opening into new freight elevator shaftways shall be constructed of fire-resistive materials. In all cases, windows shall be set in fixed sash. Elevator shaftway windows located within the first seven stories above a street or within four stories of the roof of an adjacent building shall be fitted with approved metal bars or rods at least 5/8 inch in diameter, spaced not more than 10 inches apart except where inside window protection is provided in accordance with subsection (e). Such window guards shall be provided in existing installations when, in the judgment of the Department, they are necessary.

    (e) Recesses in shaftway walls. Recesses other than for windows or recesses other than necessary for installation of elevator equipment, are not permitted. Beams, floor slabs or other building construction shall not project more than 4 inches inside the general line of the hoistway unless the top surface of the projection is beveled at an angle of not less than 75° with the horizontal. When setbacks occur in the enclosure wall, the top of the setback shall be beveled at an angle of not less than 75° with horizontal. Separator beams between adjacent elevators are not required to have bevels. The following also apply:

    (1) New installations. Recesses or offsets in shaftways of fireproof construction, except door lintels in the enclosing walk on the open sides of the car, shall be protected by substantial curtain walls, grating or vertical bars set flush with the interior walls of the shaftway, the distance between the vertical members not to exceed two inches. Such grating or bars shall be of metal. No part of the curtain walls, grating or bars shall be more than 7 inches from the car platform on any open side of the car. When the distance between the edge of the car top and rear shaftway wall exceeds 18 inches, a protective railing shall be installed the width of the car.

    (2) Existing installations. When the distance from car sill to shaftway wall on any open side of car exceeds 7 inches, curtain walls, fascia plates, vertical metal bars spaced not more than 2 inches, or a substantial metal grille of not more than 2 inch mesh, shall be provided, unless the car gate on that side is equipped with an approved interlock. When such clearance exceeds 15 inches, the car door shall be solid and equipped with an approved interlock or the shaftway constructed as specified.

    (f) Overhead loads. Overhead loads shall conform to the following:

    (1) All installations. When overhead loads are carried on angle iron towers or on structural parts of a building, such supports, as well as the supporting members, shall possess in strength a factor of safety of not less than six for steel, eight for concrete and ten for cast iron or timber. It is recommended that such factors of safety be applied to a total load assumed to be equal to the weight of all apparatus resting on the supports plus twice the weight of the maximum load to be suspended from the supports. When medium steel, cast iron, ash or yellow pine is used, sections shall be proportioned upon an ultimate tensile strength (in pounds per square inch) of 60,000 for medium steel, 16,000 for cast iron, 9,000 for ash and 9,000 for yellow pine. Cast iron shall not be used in tension.

    (2) New installations. When overhead loads are carried by bearing walls of brick, concrete or other approved materials, and such walls are erected independently of walls carrying building loads or resisting stresses, or when independent shaftway and building walls jointly carry loads, they shall be designed and constructed in accordance with the values governing safe bearing loads, as set forth in the following table:
    Safe Bearing Loads
    Brickwork


    Method
    Pounds per Square Inch
    Laid in lime mortar100
    Laid in Portland cement mortar200
    Laid in Rosedale cement mortar150
    Masonry


    Material
    Pounds per Square Inch
    Granite, capstone700
    Sandstone, squared350
    Sandstone, capstone350
    Stonework, squared175
    Rubble stonework in lime mortar 80
    Rubble stonework in cement mortar150
    Limestone, capstone500
    Square stonework250
    Rubble, in mortar 80
    Rubble, in cement mortar150
    Concrete (one part Portland, two parts sand and five parts broken stone)150
    Foundation Soils


    Material
    Tons per Square Foot
    Hard rock in native bed100
    Rock equal to ashlar masonry25—40
    Rock equal to best brick15—20
    Clay beds, dry and thick4—6
    Clay beds, moderately dry and thick 2—4
    Clay beds, soft1—2
    Gravel and coarse sand, well cemented8—10
    Sand, well cemented and compact4—6
    Sand, clean and dry2—4
    Quicksand, alluvial soils, etc.0.5—1

    (3) Existing installations. Existing shaftway construction is acceptable when, in the judgment of the Department, such construction is composed of materials of the proper strength and quality, in consideration of the fire hazards and the loads to which such walls or shaftway construction are subjected.

    (g) Other types of shaftways. Shaftways, in addition to conforming to the requirements of subsection (b), shall comply with the following:

    (1) Contiguous shaftways. When freight elevator shaftways are contiguous, and are required to be of fire-resistive construction, it is not necessary to erect walls between such shaftways. This applies equally to cases where freight and passenger elevator shaftways are contiguous.

    (2) Shaftways not extending to entire height of buildings. New freight elevator shaftways required to be of fire-resistive construction which do not extend to the entire height of a building, shall be protected by an unpierced covering, constructed of approved fire-resistive materials.

    (3) Shaftways used as thoroughfares. No new elevator shaftway shall be used as a thoroughfare when the elevator is above, below, or at the landing, except upon special permission of the Department. Existing shaftways used as thoroughfares may be required to be removed or reerected in new locations or their use as thoroughfares abandoned.

    (h) Required depth of shaftways. Freight elevator shaftways and counterweight runways shall be constructed with the pit floors and runways covered with concrete or other approved fire-resistive material to a thickness of at least four inches when the pit floor is located in the lowest cellar or basement. When the space below the shaftway is used as a passageway or is occupied by persons, or if unoccupied, is not secured against unauthorized access, the cars and counterweights shall be provided with governor-operated safeties, except that safeties operated as a result of the breaking of the suspension means may be used for dumbwaiters. Car and counterweight-buffer supports shall be of sufficient strength to withstand without failure the impact resulting from buffer engagement at governor-tripping speed or at 125% of rated speed where no governor is provided.

    (i) Shaftway enclosures. When elevators are operated outside of building walls the shaftway shall be enclosed to a height of at least 12 feet except that when such elevators have two or more car openings the shaftway enclosure shall be extended the full height of the car travel on the sides where such openings occur. Such enclosures may consist of substantial wire mesh.

    (j) Skylights and ventilators. Skylights and ventilators are permitted in freight elevator shaftways, provided the walls of the shaftways are continued to a point not less than three feet above the level of the roof. Skylights and glass ventilators shall be made of wire glass not less than 1/4 inch in thickness.

    (k) Penthouses. When penthouses are constructed over fire-resistive freight elevator shaftways, they shall be made of approved fire-resistive materials and a permanent means of entrance other than through the shaftway shall be provided. Penthouse doors shall be locked at all times, except when repairs are being made or when the machinery is being inspected or serviced. Penthouses shall have not less than a clear inside height of 6 feet and shall permit free access to all parts of machinery and apparatus therein. Existing penthouses are not required to be made fire-resistive unless existing conditions necessitate such construction. Access to all penthouses, overhead machinery, and machine rooms shall be provided by means other than through the shaftway.

Notation

Cross References

This section cited in 34 Pa. Code § 7.279 (relating to machinery); 34 Pa. Code § 7.291 (relating to general); and 34 Pa. Code § 7.295 (relating to hydraulic freight elevators).