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.]