511 EM 385-1-1 Chapters 9-15

Sections

14-8. General Requirements.

Material Handling: Conveyors

Construct and install conveyors as per manufacturer's instructions, ensure safe access for maintenance, and ground them properly.
Do not maintain conveyors while in operation unless personnel are trained, and follow HEC procedures for non-routine maintenance.

Safety Devices and Guards

Install anti-runaway devices, brakes, backstops, or other safeguards on all conveyors where reversing or runaway are potential hazards, or the effects of gravity create a potential for hazardous uncontrolled lowering.
Install safety devices and warning systems, ensuring they are audible and provide sufficient warning before conveyor operation.
Guard all exposed moving parts, especially nip and shear points, and ensure lubrication points are safely accessible.
Provide adequate guarding or warnings for conveyors that cannot be enclosed, and ensure spill guards are in place if needed.

Access and Operating Controls

Provide safe crossovers or underpasses, and guard conveyors passing over public areas to catch dislodged materials.
Install emergency stop devices in hazardous areas, ensuring they are easily identifiable, accessible, and cannot be overridden.
Label and arrange controls clearly, ensuring conveyors won't resume after an emergency stop without manual reset.

Additional Features and Operations

Ensure counterweights and mobile conveyors are safely confined or equipped with locking devices to prevent hazards.
Guard hopper and chute openings, or provide warnings, and ensure dump hoppers are equipped with appropriate grating.
Operate conveyors within their design limits, check clearances, correct issues after emergency stops, and maintain cleanliness.

Knowledge Check Choose the best answer for the question.

14-5. Install anti-runaway devices, brakes, backstops, or other safeguards on all conveyors _____.

unless warning signs are posted on the equipment

in areas exposed to the public

where reversing or runaway are potential hazards

within 55 feet of other hazardous operations

You forgot to answer the question!

EM 385-1-1 Paragraph 14-8 (a.(9)–a.(9)(q-6).

14-2. General Requirements. (a.(9)–a.(9)(q-6).

a.  Material Handling.

(9)  Conveyors.

(a)  Construct and install conveyor and hauling systems according to the manufacturer's instructions.

(b)  Provide safe access to permit inspection, lubrication, repair, and maintenance activities.

(d)  Do not perform maintenance while a conveyor is in operation unless personnel are trained on the associated hazards (see para 14-3.b).

(e)  Use HEC procedures for maintenance and servicing activities other than routine lubrication which is done without removing guards (see chapter 12).

(f)  Safety Devices.

(f-1)  Install anti-runaway devices, brakes, backstops, or other safeguards on all conveyors where reversing or runaway are potential hazards, or the effects of gravity create a potential for hazardous uncontrolled lowering.

(f-2)  Design safety devices to prevent the conveyor from automatically restarting until the safety device has been manually reset.

(f-3)  Arrange safety devices to operate in such a manner that if power failure or a mechanical failure of the device occurs a hazardous condition will not result.

(f-4)  Equip conveyor systems with a time-delay audible and visual warning signal to be sounded immediately before starting of the conveyor.

(f-5)  Warning devices must be clearly audible at all points along the conveyor where personnel may be present.

(f-6)  Warning devices must be activated by the controller device that starts the conveyor and must continue for a period before the conveyor starts.

(f-7)  For overland conveyor systems, warning devices are required only at the transfer, loading, and discharge points and those points where personnel are normally stationed.

(f-8)  In areas not exposed to the public, provide clear, concise, and legible warning signs that indicate the conveyor system may start at any time if the function of the system would be seriously hindered or adversely affected by the required time delay, or if the intent of the warning may be misinterpreted.  These warning signs must say that danger exists, the conveyor may start without warning and personnel must keep clear. Post warnings signs along the conveyor in all areas that are not guarded or otherwise protected by their location.

(g)  Mechanically guard or guard by location all exposed moving machinery parts that present a hazard.

(g-1)  Guard all nip and shear points.

(g-2)  Provide guards at points where personnel could contact cables, chains, belts, and runaways of exposed bucket conveyors.

(g-3)  When lubricating while the conveyor is in motion, lubrication points must be accessible through guard openings that prevent fingers or other small tools from reaching the hazardous locations.

(g-4)  If guards need to be removed for adjustment or maintenance of the conveyor, use HEC procedures prior to removing the guards according to chapter 12.

(g-5)  In lieu of guarding individual nip and shear points, take-up mechanisms may be guarded by placing standard railings, or fencing and warning signs, around the area.

(g-6)  In the case of a trolley conveyor when mechanical or electrical guarding would render the conveyor unusable, conspicuously post prominent, and legible warnings in the area or on the equipment.  Additionally, where feasible, place barricades or mark lines on the ground to indicate the hazard area.

(g-7)  Unless guarded by location, provide sections of chain conveyors that cannot be enclosed without impairing the function with warning signs or personnel barriers.

(g-8)  Provide conveyors with spill guards, pan guards, or the equivalent if there is a potential for material to fall off the conveyor and endanger personnel or equipment.

(g-9)  At transfer, loading, and discharge points, prevent unconfined and uncontrolled free fall of material if the material would create a hazard to personnel. Free fall of material can result from flooding, ricocheting, overloading, trajectory, leakage, or a combination thereof.

(g-10) In the absence of a guard specifically erected to protect personnel, provide warnings to restrict unauthorized personnel from entering such hazardous areas.

(g-11) At all points along the conveyor, except where loads are removed from or placed on a conveyor or where a conveyor discharges to or receives material from another conveyor, make provisions to eliminate the possibility of loads or material being dislodged from the conveyor.

(g-12) Remove build-up of excess material from all points along the conveyor.

(h)  Access.

(h-1)  Provide crossovers or underpasses with safeguards for passage over or under all conveyors.  Do not cross over or under conveyors except where safe passageways are provided.

(h-2)  Install protective guards whenever conveyors pass next to, or over, work areas, roadways, highways, railroads, or other public passageways.  The guards must be designed to catch and hold any load or material that may fall off or become dislodged from the system.

(h-3)  Where conveyors are operated in tunnels, pits, and similar enclosures, provide ample room for safe access and operating space for all personnel.

(i)  Operating Controls.

(i-1)  Provide emergency stop buttons, pull cords, limit switches, or similar emergency devices at the following locations unless the design, construction, and operation of a conveyor is determined to be non-hazardous to personnel:  operator stations, loading arms, transfer points, and other potentially hazardous locations on the conveyor path not otherwise protected.

(i-2)  Emergency stop buttons must be RED in color, easily identifiable, and readily accessible. Do not protect them with collars or other devices that could affect their operation during an emergency.

(i-3)  Emergency stop devices must act directly on the control of the conveyor concerned and may not depend on the stopping of any other equipment.  For a multi- conveyor system, the emergency stop must stop all conveyors that are tied together.

(i-4)  Install emergency stop devices so that they cannot be overridden from other locations.

(i-5)  Starting controls must be GREEN in color and be protected from accidental activation.

(i-6)  Clearly label all controls to identify their function.

(i-7)  Arrange conveyor controls so that in case of an emergency stop the conveyor operations will not resume until the operator has manually reset or restarted the conveyor at the location where the emergency stop was initiated.

(i-8)  Arrange and locate control stations so that the operation of the equipment is visible from them.

(j)  Gates and Switches.

(j-1)  Provide power-positioned gate and switch sections with devices that will prevent these sections from falling in case of power failure.

(j-2)  Provide means on all gates and switch sections to prevent conveyed material from discharging into the open area created when lifting the gate or switch.

(k)  Counterweights.

(k-1)  Confine counterweights supported by belts, cables, chains, or similar means, inside an enclosure to prevent injury to personnel or include an arrangement that will restrain the falling weight in case of failure of the normal counterweight support.

(k-2)  Securely fasten counterweights attached to lever arms.

(l) When two or more conveying systems are interfaced, the interfaced areas must contain adequate guarding and safety devices.

(m)  Hoppers and Chutes.

(m-1)  Guard all openings to the hopper and chutes to prevent persons from accidentally stepping into them.  If guards are not practical, conspicuously post warning signs.

(m-2)  Equip dump hoppers that have a hopper flush with the floor and cannot be guarded with grating having a maximum opening of 4 inches (10.2 cm) and heavy enough to withstand any load imposed on it.  If the openings in the grating are larger or if no grating is provided, place temporary railing around ground level hoppers when dumping operation are not in progress.  During dumping operation, place warning signs in conspicuous locations warning personnel of an open pit.

(n)  Mobile Conveyors.

(n-1)  Provide mobile conveyors with brakes or other position locking devices where movement would present a hazard.

(n-2)  Design mobile conveyors to prevent runaway and remain stable against overturning under normal conditions of operation.

(n-3)  When an operator is required on a mobile conveyor, provide a platform or cab for their protection.

(o)  Portable Conveyors.

(o-1)  Provide portable conveyors with a safety device on the raising and lowering mechanism of the boom to hold the boom at any rated angle of inclination.

(o-2)  Portable conveyors must be stable so that the conveyor will not topple when used within the manufacturer's rating and in a manner in which it was intended or when being moved.

(p)  Screw Conveyors.

(p-1)  Do not operate the screw conveyor unless the conveyor housing completely encloses the conveyor’s moving elements and the power transmission guards are in place. If the conveyor must have an open housing as a condition of use, then guard the entire conveyor by railing, fence, or by location.

(p-2)  Construct feed openings for shovel, front-end loader, or other manual or mechanical equipment so that the conveyor screw is always covered by grating.  If grating cannot be used, guard the exposed section of the conveyor by a railing and conspicuously post warning signs.

(q)  Operation.

(q-1)  Use conveyors only for materials for which it was designed and within the rated capacities and speeds.

(q-2)  At installation of flight and apron conveyors, “jog” or hand run through at least one complete revolution to check design clearances prior to running under automatic power.

(q-3)  Before restarting a conveyor that has been stopped because of an emergency, conduct an inspection of the conveyor, determine the cause of the emergency stop, and make corrections.

(q-4)  Keep the area around loading and unloading points clear of obstructions that could create a hazard.

(q-5)  Maintain rotating drive pulleys and conveyor belts according to the manufacturer’s instructions.

(q-6)  Clean the conveyors as often as required to ensure safe operation.