PDFWAC 296-307-28060
Materials used for guardrails and toeboards.
(1) A guardrail used to guard power transmission parts must be 42 inches tall, with a midrail between the top rail and the floor.
(2) Posts must be 8 feet apart or less. They must be permanent and substantial, smooth, and free from protruding nails, bolts, and splinters. If made of pipe, the post must be at least 1-1/4 inches inside diameter. If posts are made of metal shapes or bars, the section must be as strong as posts made of 1-1/2 by 1-1/2 by 3/16-inch angle iron. If posts are made of wood, the posts must be at least 2 by 4 inches. The upper rail must be 2 by 4 inches, or two 1 by 4 inch strips, one at the top and one at the side of the posts. The midrail must be at least 1 by 4 inches.
(3) The rails (metal shapes, metal bars, or wood), should be on the side of the posts that gives the best protection and support. Where panels are fitted with expanded metal or wire mesh (as noted in Table 1) the middle rails may be omitted. Where guard is exposed to contact with moving equipment, additional strength may be necessary.
(4) Toeboards must be at least 4 inches tall, of wood, metal, or metal grill of a maximum 1-inch mesh. Toeboards at flywheel pits should be placed as close to edge of the pit as possible.
Table P-1
TABLE OF STANDARD MATERIALS AND DIMENSIONS
Material | Clearance from moving part at all points (inches) | Largest mesh or opening allowable (inches) | Minimum gauge (U.S. Standard) or thickness (inches) | Minimum height of guard from floor or platform level (feet) |
Woven wire | Under 2 2-4 Under 4 4-15 | 3/8 1/2 1/2 2 | No. 16 No. 16 No. 16 No. 12 | 7 7 7 7 |
Expanded metal | Under 4 4-15 | 1/2 2 | No. 18 No. 13 | 7 7 |
Perforated metal | Under 4 4-15 | 1/2 2 | No. 20 No. 14 | 7 7 |
Sheet metal | Under 4 4-15 | No. 22 No. 22 | 7 7 | |
Wood or metal strip crossed | Under 4 4-15 | 3/8 2 | Wood 3/4 Metal No. 16 Wood 3/4 Metal No. 16 | 7 7 |
Wood or metal strip not crossed | Under 4 4-15 | 1/2 width 1 width | Wood 3/4 Metal No. 16 Wood 3/4 Metal No. 16 | 7 7 |
Standard rail | Min. 15 Max. 20 |
Table P-2
HORIZONTAL OVERHEAD BELTS, ROPES, AND CHAINS
7 FEET OR MORE ABOVE FLOOR OR PLATFORM
Width 0"-14" inclusive | Material | |||
MEMBERS | ||||
Framework | 1 1/2" x 1 1/2" x 1/4" | Angle iron | ||
Filler (belt guards) | 1 1/2" x 3/16" | Flat iron | ||
Filler and vertical side member | No. 20 A.W.G. | Solid sheet metal | ||
Filler supports | 2" x 5/16" flat iron | Flat and angle | ||
Guard supports | 2" x 5/16" | Flat iron | ||
FASTENINGS | ||||
Filler supports to framework | (2) 3/16" | Rivets | ||
Filler flats to supports (belt guards) | (1) 5/16" | Flush rivets | ||
Filler to frame and supports (chain guards) | 3/16" | Rivets spaced | ||
Guard supports to framework | (2) 3/6" | Rivets or bolts | ||
Guard and supports to overheard ceiling | 1/4" x 3 1/2" lag screws or 1/2" bolts | Lag screws or bolts | ||
DETAILS-SPACING, ETC. | ||||
Width of guards | One-quarter wider than belt, rope, or chain drive | |||
Spacing between filler supports | 20" center to center | |||
Spacing between filler flats (belt guards) | 2" apart | |||
Spacing between guard supports | 36" center to center | |||
OTHER BELT GUARD FILLING PERMITTED | ||||
Sheet metal fastened as in chain guards | No. 20 A.W.G. | Solid or perforated | ||
Woven Wire, 2" mesh | No. 12 A.W.G. | |||
CLEARANCE FROM OUTSIDE OF BELT, ROPE, OR CHAIN DRIVE TO GUARD | ||||
Distance center to center of shafts | Up to 15' inclusive | Over 40' | ||
Clearance from belt, or chain to guard | 16" | 120" | ||
Width over 14" to 24" inclusive | Material | |||
MEMBERS | ||||
Framework | 2" x 2" x 5/16" | Angle iron | ||
Filler (belt guards) | 2" x 3/16" | Flat iron | ||
Filler and vertical side member | No. 18 A.W.G. | Solid sheet metal | ||
Filler supports | 2" x 3/8" flat iron | Flat and angle | ||
Guard supports | 2" x 3/8" | Flat iron | ||
FASTENINGS | ||||
Filler supports to framework | (2) 3/6" | Rivets | ||
Filler flats to supports (belt guards) | (1) 5/16" | Flush rivets | ||
Filler to frame and supports (chain guards) | 8" centers on sides and 4" centers on bottom | |||
Guard supports to framework | (2) 7/16" | Rivets or bolts | ||
Guard and supports to overheard ceiling | 5/8" x 4" lag screws or 5/8" bolts | Lag screws or bolts | ||
DETAILS-SPACING, ETC. | ||||
Width of guards | ||||
Spacing between filler supports | 16" C. to C | |||
Spacing between filler flats (belt guards) | 2 1/2" apart | |||
Spacing between guard supports | 36" C. to C | |||
OTHER BELT GUARD FILLING PERMITTED | ||||
Sheet metal fastened as in chain guards | No. 18 A.W.G. | Solid or perforated | ||
Woven wire, 2" mesh | No. 10 A.W.G. | |||
CLEARANCE FROM OUTSIDE OF BELT, ROPE, OR CHAIN DRIVE TO GUARD | ||||
Distance center to center of shafts | Over 15' to 25' | Over 40' inclusive | ||
Clearance from belt/chain to guard | 10" | 20" | ||
Width over 24" | Material | |||
MEMBERS | ||||
Framework | 3" x 3" x 3/8" | Angle iron | ||
Filler (belt guards) | 2" x 5/16" | Flat iron | ||
Filler and vertical side member | No. A.W.G. | Solid sheet metal | ||
Filler supports | 2 1/2" x 2 1/2" x 1/4" angle | Flat and angle | ||
Guard supports | 2 1/2" x 3/8" | Flat iron | ||
FASTENINGS | ||||
Filler supports to framework | (3) 1/2" | Rivets | ||
Filler flats to supports (belt guards) | (2) 3/8" | Flush rivets | ||
Filler to frame and supports (chain guards) | ||||
Guard supports to frame work | (2) 5/8" | Rivets or bolts | ||
Guard and supports to overhead ceiling | 3/4" x 6" lag screws or 3/4" bolt | Lag screws or bolts | ||
DETAILS-SPACING, ETC. | ||||
Width of guards | ||||
Spacing between filler supports | 16" C. to C. | |||
Spacing between filler flats (belt guards) | 4" apart | |||
Spacing between guard supports | 36" C. to C. | |||
OTHER BELT GUARD FILLING PERMITTED | ||||
Sheet metal fastened as in chain guards | No. 18 A.W.G. | Solid or perforated | ||
Woven wire, 2" mesh | No. 8 A.W.G. | |||
CLEARANCE FROM OUTSIDE OF BELT, ROPE, OR CHAIN DRIVE TO GUARD | ||||
Distance center to center of shafts | Over 25' to 40' inclusive | Over 40' | ||
Clearance from belt, or chain to guard | 15" | 20" |
[Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, and 49.17.060. WSR 20-21-091, § 296-307-28060, filed 10/20/20, effective 11/20/20. Statutory Authority: RCW 49.17.040. WSR 98-24-096, § 296-307-28060, filed 12/1/98, effective 3/1/99. WSR 97-09-013, recodified as § 296-307-28060, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. WSR 96-22-048, § 296-306A-28060, filed 10/31/96, effective 12/1/96.]