Labor & Industries (L&I), Washington State

Machine Safety Chapter 296-806, WAC

Effective Date: 01/01/05

WAC 296-806-420 Conveyors

For printing

PUSHER-BAR CONVEYORS

WAC 296-806-42054  

Guard pusher-bar conveyors

You must

• Provide a guard when hazards exist at each of these points:
  • – At the discharge point where the bar passes through the bed
  • – Where there's a shear point between the return pusher bar and a frame member

ROLLER CONVEYORS

WAC 296-806-42056

Prohibit walking on roller-type conveyors

You must

• Prohibit employees from walking on the rolls of roller-type conveyors.
• Tread plates or other types of walkways can be used between the rollers as a walking surface for operators when performing their duties.

WAC 296-806-42058

Use speed controls for roller and wheel conveyors

You must

• Avoid safety hazards created by unit or package speeds by one of the following methods:
  • – Limiting the length of the sloped run
  • – Using speed retarders or brakes
  • – Other means of providing speed control
• Make sure rollers and wheels are free running to prevent locked wheels from steering or pulling materials to one side or off the conveyor.

WAC 296-806-42060

Safeguard belt-driven live roller conveyors

You must

• Guard belt and roller nip points by one of the following methods:
  • – Space load-carrying rollers to prevent access to the belt and roller nip points.
  • – Insert rods or plates between the rollers to prevent access to the belt and roller nip points.
  • – Use rollers that pop out when something contacts the nip point.
  • – Distance safeguarding found in:
    • Make sure safeguarding by distance meets these requirements, WAC 296-806-20056.

Reference: For nip points and sheer hazards on power-driven (live) roller conveyors see Guard nip points on belt conveyors, WAC 296-806-42028.

SCREW CONVEYORS

WAC 296-806-42062

Guard screw conveyors

You must

• Enclose the rotating screw to prevent contact with the shear points where it passes the sides of the trough or casing
• Guard screw conveyors requiring an open housing by using one of the following:
  • – Make sure safeguarding by distance meets these requirements,
    WAC 296-806-20056
  • – Make sure guardrails used for safeguarding meet these requirements, WAC 296-806-20058
• Construct feed openings for shovel, front-end loader, or other manual or mechanical equipment so that the conveyor screw is covered by a grating.
  • – If the nature of the material is such that a grating can't be used, then the exposed section of the conveyor must be guarded by a railing and warning signs.

SKIP HOISTS

WAC 296-806-42064

Provide slack-cable switches on hoists

You must

• Provide and arrange slack cable switches to cut power to the drive and set the brake when the skip or counterweight hoisting ropes either:
  • – Develop slack
    or
  • – Lose tension due to sticking in the guides, over travel, or for any other reason.

WAC 296-806-42066

Block the skip bucket and counterweight guides

You must

• Make sure the skip bucket and counterweight are blocked in their guides when the brake or any part of the drive train between the brake and the drum shaft are being repaired or replaced.

WAC 296-806-42068

Protect against wire rope coming off sheaves

You must

• Fit all sheaves with sheave guards to prevent the wire rope from coming off under slack cable or similar conditions

SLAT AND ROLLER-SLAT CONVEYORS

WAC 296-806-42070

Safeguard slat and roller-slat conveyors

You must

• Provide either of these safeguards at the tail end of a slat conveyor if the slats are above the centerline of the chain:
  • – A guard over the hazardous tail end
    or
  • – Warning signs if guards are impractical because of material flowing over the tail sprocket
• Provide either of these safeguards when there's a gap between the slats wide enough to permit access to cross members below the slats:
  • – A continuous pan under the slats
    or
  • – Keep all cross members a safe distance from the slats

TOWED CONVEYORS

WAC 296-806-42072

Provide a safe method for disengaging the tow pin

You must

• Provide a method for the operator to disengage the tow pin from a conveyor pusher without being in front of the cart.

WAC 296-806-42074

Protect employees from moving carts on towed conveyors

You must

• Make sure runaway carts are unable to exit ramps and enter work areas.
• Have a barrier of sufficient strength and height on ramps with pedestrian or traffic aisles to prevent a runaway cart from entering the aisle.
• Have signs warning employees not to enter ramps that don't have pedestrian or traffic aisles.

 

WAC 296-806-42076

Provide clearances and warnings for carts on towed conveyors

You must

• Provide clearance space for personnel in all of the following:
  • – Between the sides of carts
  • – Between any load overhanging the side of a cart
  • – Any fixed or moving object
• Identify the cart path with floor stripes that are:
  • – Parallel to the cart path
  • – Arranged so one line is on each side of the path
  • – Located a safe distance from the edge of the cart or overhanging load
• Mark reduced clearance areas with appropriate warning signs.

Note: An example of a reduced clearance area is an area where a cart goes through a wall opening.

You must

• Place an appropriate warning on those areas where a cart may unexpectedly change direction, such as switching off the main line into a transfer conveyor or a spur.

Note: An example of an appropriate warning would be to use diagonal stripes on the floor between clearance lines.

You must

• Install a sign, signal, or other warning where carts start automatically.

WAC 296-806-42078

Mark projections above the floor

You must

• Mark the area around projections above the floor with appropriate diagonal stripes, warning signs, or both.

Note: This is especially important if projections above the floor are unpredictable or occur intermittently.