OAR 437-004-0360
Fixed Ladders
(1)
Definitions. Fixed ladder terms mean:(a)
Cage. A guard sometimes referred to as a basket guard that is an enclosure fastened to the side rails of a fixed ladder or to a structure to encircle the climbing space of the ladder.(b)
Cleats. Ladder cross-pieces of rectangular cross-section placed on edge on which a person may step when climbing up or down.(c)
Fastenings. A device to attach a ladder to a structure, building, or equipment.(d)
Fixed ladder. A ladder permanently attached to a structure, building, or equipment.(e)
Grab bars. Individual handholds adjacent to or as an extension above ladders to provide access beyond the limits of the ladder.(f)
Individual-rung ladder. A fixed ladder with each rung individually attached to a structure, building, or equipment.(g)
Ladder. A device with steps, rungs or cleats between rails, for people to climb up or down.(h)
Ladder safety device. Any device, other than a cage or well, designed to eliminate or reduce the possibility of accidental falls, that may use life belts, friction brakes, and sliding attachments.(i)
Pitch. The included angle between the horizontal and the ladder, measured on the opposite side of the ladder from the climbing side.(j)
Rail ladder. A fixed ladder with side rails joined at regular intervals by rungs or cleats and fastened in full length or in sections to a building, structure, or equipment.(k)
Railings. Any one or a combination of those railings made according to OAR 437-004-0320 (Guarding Floor and Wall Openings and Holes). A standard railing is a vertical barrier along exposed edges of walking surfaces to prevent people from falling.(l)
Rungs. Ladder cross-pieces of circular or oval cross-section on which a person may step when climbing up or down.(m)
Side-step ladder. One from which a person getting off at the top must step sideways to reach the landing.(n)
Steps. The flat cross-pieces of a ladder on which a person may step when climbing up or down.(o)
Through ladder. A ladder from which a person getting off at the top must step through to reach the landing.(p)
Well. A permanent complete enclosure around a fixed ladder, that is attached to the walls of the well. Proper clearances for a well will give the climber the same protection as a cage.(2)
Design requirements. Design considerations: All ladders, appurtenances, and fastenings must meet these load requirements:(a)
The minimum design live load must be a single concentrated load of 200 pounds.(b)
Design consideration must include the number and position of additional concentrated live load units of 200 pounds each as determined from anticipated use.(c)
Consider the live loads caused by persons on the ladder to be concentrated at such points as will cause the maximum stress in the structural member being under evaluation.(d)
Use the weight of the ladder and attachments together with the live load when designing rails and fastenings.(e)
All wood parts of fixed ladders must meet the requirements of OAR 437-004-0340 (Portable Ladders)(3).(f)
For fixed ladders with wood side rails and wood rungs or cleats, used at an angle between 75° and 90°, and intended for use by no more than one person per section, single ladders in OAR 437-004-0340 (Portable Ladders)(8)(b)(A) are acceptable.(3)
Specific features.(a)
Rungs and cleats.(A)
All rungs must have a minimum diameter of 3⁄4 inch for metal ladders, except as in paragraph OAR 437-004-0360 (Fixed Ladders)(3)(g)(A) and a minimum diameter of 1-1⁄8 inches for wood ladders.(B)
The distance between rungs, cleats, and steps must be uniform and not more than 12 inches.(C)
The minimum clear length of rungs or cleats must be 16 inches.(D)
Rungs, cleats, and steps must not have splinters, sharp edges, burrs, or projections.(E)
The rungs of an individual rung ladder must not allow the climber’s foot to slide off the end. Figure 2 shows a suggested design. [Figure not included. See ED. NOTE.](b)
Side rails. Side rails that might be used as a climbing aid must be of such cross sections as to afford adequate gripping surface without sharp edges, splinters, or burrs.(c)
Fastenings. Fastenings must be an integral part of fixed ladder design.(d)
Splices. All splices must meet design requirements noted in (a) above. All splices and connections must have smooth transition with original members and no sharp or extensive projections.(e)
Electrolytic action. Protect dissimilar metals from electrolytic action when they are joined.(f)
Welding. All welding must be according to the “Code for Welding in Building Construction” (AWSD1.0-1966).(g)
Protection from deterioration. Paint or treat metal ladders and attachments to resist corrosion and rusting when necessary. Ladders with individual metal rungs imbedded in concrete, that serve as access to pits and to other areas under floors, must have rungs with a minimum diameter of 1 inch or paint or treatment to resist corrosion and rusting.(4)
Clearance. [Figure not included. See ED. NOTE.](a)
Climbing side. On fixed ladders, the perpendicular distance from the centerline of the rungs to the nearest permanent object on the climbing side of the ladder must be 36 inches for a pitch of 76°, and 30 inches for a pitch of 90° (fig. 3), with minimum clearances for intermediate pitches varying between these two limits in proportion to the slope, except as in (4)(c) and (e) below.(b)
Ladders without cages or wells. There must be a clear width of at least 15 inches each way from the centerline of the ladder in the climbing space, except when cages or wells are necessary.(c)
Ladders with cages or baskets. Subparagraphs (4)(a) and (b) above do not cover ladders with a cage or basket. They must conform to (5)(a)(E). Subparagraph (4)(a) above does not cover fixed ladders in smooth-walled wells. They must conform to (5)(a)(F).(d)
Clearance in back of ladder. The distance from the centerline of rungs, cleats, or steps to the nearest permanent object in back of the ladder must be not less than 7 inches, except that when there are unavoidable obstructions, there must be minimum clearances shown in Figure 4. [Figure not included. See ED. NOTE.](e)
Clearance in back of grab bar. The distance from the centerline of the grab bar to the nearest permanent object in back of the grab bars must be not less than 4 inches. Grab bars must not protrude on the climbing side beyond the rungs of the ladder that they serve.(f)
Step-across distance. The step-across distance from the nearest edge of the ladder to the nearest edge of equipment or structure must be not more than 12 inches, or less than 2-1⁄2 inches (fig. 5). [Figure not included. See ED. NOTE.](g)
Hatch cover. Counterweighted hatch covers must open a minimum of 60° from the horizontal. The distance from the centerline of rungs or cleats to the edge of the hatch opening on the climbing side must be not less than 24 inches for offset wells or 30 inches for straight wells. There must be no protruding potential hazards within 24 inches of the centerline of rungs or cleats; any such hazards within 30 inches of the centerline of the rungs or cleats must have deflector plates at an angle of 60° from the horizontal as shown in figure 6. The relationship of a fixed ladder to an acceptable counterweighted hatch cover is shown in figure 7. [Figures not included. See ED. NOTE.](5)
Special requirements.(a)
Cages, Wells and Ladder Climbing Safety systems.(A)
Cages, wells or laddders climbing safety systems must be on all ladders (except chimneys) where the length of climb is more than 24 feet but not more than 50 feet or the top of the ladder is more than 24 feet above the ground or nearest lower landing surface.(B)
Ladders with a length of climb more than 50 feet (except chimneys) must have a cage, well or climbing safety system and must meet one of the following two requirements:(i)
When using a cage or well the ladder must be in sections, horizonitally offset, with real platforms at least every 50 feet.(ii)
When using a climbing safety system the ladder must have rest platforms at least every 150 feet. [Figure not included. See ED. NOTE.](C)
Cages must extend at least 42 inches above the top of the landing, unless there is other acceptable protection.(D)
Cages must extend down the ladder to a point not less than 7 feet nor more than 8 feet above the base of the ladder. The bottom must flare not less than 4 inches or a portion of the cage opposite ladder must extend to the base.(E)
Cages must not extend less than 27 nor more than 28 inches from the center line of the rungs of the ladder. Cages must not be less than 27 inches in width. The inside must be clear of projections. Vertical bars must be at a maximum spacing of 40 degrees around the circumference of the cage; this will give a maximum spacing of approximately 9-1⁄2 inches, center to center.(F)
Ladder wells must have a clear width of at least 15 inches measured each way from the center line of the ladder. Smooth-walled wells must be a minimum of 27 inches from the center line of rungs to the well wall on the climbing side of the ladder. Where other obstructions on the climbing side of the ladder exist, there must be a minimum of 30 inches from the centerline of the rungs. [Figures not included. See ED. NOTE.](b)
Landing platforms.(A)
Where a person has to step a distance more than 12 inches from the center line of the rung of a ladder to the nearest edge of a structure or equipment, there must be a landing platform. The minimum step-across distance is 2-1⁄2 inches.(B)
All landings must have standard railings and toeboards, that give safe access to the ladder. Platforms must be not less than 24 inches wide and 30 inches long.(C)
One rung of any section of ladder must be at the level of the landing laterally served by the ladder. Where access to the landing is through the ladder, the rung spacing from the landing platform to the first rung below the landing must be the same as on the ladder.(c)
Ladder extensions. The side rails of through or side step ladder extensions must extend 3-1⁄2 feet above parapets and landings. For through ladder extensions, omit the rungs from the extension. There must be not less than 18 nor more than 24 inches clearance between rails. For side step or offset fixed ladder sections, at landings, the side rails and rungs must extend to the next regular rung beyond or above the 3-1⁄2 foot minimum (fig.11). [Figure not included. See ED. NOTE.](d)
Grab bars. Space grab bars by a continuation of the rung spacing when they are horizontal. Vertical grab bars must have the same spacing as the ladder side rails. Grab bar diameters must be the equivalent of the round rung diameters.(6)
Pitch.(a)
Preferred pitch. The preferred pitch of fixed ladders is between 75° and 90° with the horizontal (fig. 12). [Figure not included. See ED. NOTE.](b)
Substandard pitch. Fixed ladders are substandard if they are between 60° and 75° with the horizontal. Substandard fixed ladders are allowed only where necessary to meet conditions of installation.(c)
Scope of coverage in this section. This section covers only fixed ladders between 60° and 90° with the horizontal.(d)
Pitch more than 90°. No ladder may be more than 90° with the horizontal.(7)
Maintenance. All ladders must be in safe condition. Inspect ladders at intervals determined by use and exposure.
Source:
Rule 437-004-0360 — Fixed Ladders, https://secure.sos.state.or.us/oard/view.action?ruleNumber=437-004-0360.