Safety recommendations to minimize risks in the woodyard

 

NOTE:  Do not operate any equipment before becoming familiar with the design and operation of that equipment and the surrounding machinery/environment. Make sure to read all of the OEM safety documents.

 

Woodyard machinery is designed to minimize risks. Design features include:

• using the "risk reduction by design" principle throughout the design process, 
• guards and fences positioned to limit access to hazardous locations,
• warning signs and colors used to draw attention to hazards or moving equipment, 
• shut-off valves, limit switches and logic program interlocks which prevent improper operation, and
• emergency stop controls located in danger areas, for use in case of life-threatening situations.

However, despite safety-conscious equipment designs, operators must still exercise extreme caution around woodyard machinery.

This article addresses general safety issues related to typical woodyard operations. The safety recommendations listed here are not all inclusive, but can be used to reinforce a mill's safety program.

General woodyard safety recommendations

Operators should make themselves familiar with the function and purpose of each safety feature and make sure that none are ever disabled. If any safety features are not functioning properly, the equipment should not be operated until repairs are made and all safety features are restored.

 

CAUTION:  The operating staff should be well trained and all new employees should be trained and familiarized with the operating or maintenance work they are assigned to do. The employees should be aware of what to do in an emergency.

 

Heed warning and safety notices posted on the machine and in the area. They are installed to warn personnel of possible danger. Observe all instructions. Never remove warning signs. Replace them when worn.

Routinely check the structural integrity and operation of all equipment:

• Check the operation of all emergency stops, electrical interlocks, and related limit switches on a regular basis to assure proper operation. Safety faults must be repaired and cleared by qualified personnel before resuming operation. Check for proper operation of all alarm signals, flashing lights, and alarm horns. Check alarm screens for any alarms and correct faults as needed.
• Check that all fluid systems are functioning correctly (motors, pumps, hoses, cylinders, pressure). Check for air and oil leaks. Replace worn parts.
• Check for mechanical integrity and wearing of components. Parts prone to occasional failure include rolls, wires, drive shafts and chains. Loose or worn components may fail, creating flying debris hazards. Check fasteners securing the frames and other components to the foundations. Report loose plates on manholes and clean-out holes.
• Make sure that all warning signs, barriers, guards, and safety fences/gates are in place and in good working order before starting the machinery. They have been installed to protect personnel.

Handle the equipment at the control console with care. Do not place objects on the keyboard, color display, or pointing device (joystick or trackball). All equipment is susceptible to failure if placed in contact with liquids or excessive heat and/or humidity. Allow adequate air flow around the units at all times. Operate the keyboard and pointing device with reasonable pressure.

Keep the area around the machine clean, and free from obstructions of any kind:

• Make sure that all controls are completely accessible.
• Keep foreign articles off footwalks and out of walkways to prevent personnel from tripping and falling into machinery.
• Wipe up spilled oil, grease, water, kerosene, or other solutions which may cause a person to slip.

To prevent accidents, avoid working in the vicinity of the machine during operations except when absolutely necessary. When tasks require operators to work in the immediate vicinity of the machine, use extreme caution.

Use appropriate personal protective equipment (PPE):

• With the exception of the control room, all personnel in the machine area should wear a hard hat, ear plugs, eye protection with side shields, and steel-toe shoes.
• Appropriate gloves should be worn when handling sharp items or harmful substances such as hot steam, hydraulic oil, grease, or detergents.
• A helmet light or other appropriate lighting should be used when working in enclosed or dark areas.
• A safety harness should be worn when working in areas where protective devices have been removed for maintenance.

Do not exceed machine specifications. The equipment provided is designed only for the intended conditions. Equipment failure from exceeding specifications (speed, roll sizes, etc.) could result in serious injury or death. Excessive speed can lead to damaging vibration.

Beware of moving equipment even when apparently stopped.

Any nip point on this equipment is a danger area. Keep clothing and all parts of the body away from ingoing nips, conveyors, drive shafts, chains, chipper knives, and rotating or loading mechanisms. There is a hazard of being drawn in or crushed. Do not wear any loose clothing which could become entangled in nips.

Never place any body parts (hands, head, feet) through openings on the framework.

Be especially cautious when standing or working in the vicinity of belt or conveyor nips. Keep all parts of the body away from belt drives.

Prior to starting the machinery, check that no person or object is near moving parts and that all personnel have exited specified danger areas.

Do not overreach. Keep proper footing at all times. Be especially careful in inclement weather to avoid falls. The continuously wet environment creates an extremely hazardous condition for footing. Surfaces are slippery. Use non-skid surfaces wherever possible in operating areas.

Never remove guards or other protective devices except during maintenance. Make sure that all equipment is replaced before operation is resumed.

Hazards located beyond reach from designated operator positions are not required to have guarding. Do not use ladders, stools, or other devices to reach these areas unless the entire machine has been locked out.

Do not walk, stand, or reach under any moving component unless all fluid and electrical supply circuits are locked out and the component is properly supported. Unexpected movements could cause serious injuries or death.

Stop the machinery immediately if a sharp increase in vibration is noted. This may indicate machine damage which could result in flying debris or components.

Do not touch steam joints, hoses or valves. Surface temperatures can exceed 194 °F. Touching these components will cause burns.

To improve safety at work and working conditions, special attention should be paid to cleanliness by keeping floors and equipment and their surroundings tidy.

When moving around in the mill area, use only marked walkways and service routes. The service platforms of a woodroom consist of walkways and service areas. They are generally located near the machines which usually have dangerous points or zones. Therefore, mind your step when going on the platforms and pay attention to the warning signs. When moving around on the service platforms, beware of strong winds especially at high levels.

 

WARNING:  Do not climb on the railings. Do not open the locking access gates to dangerous zones without permission of the control room. It is strictly forbidden to throw or drop any objects from the platforms unless there is an area below particularly reserved for this purpose and barred with guard railings. Make sure the area is clear of people before dropping anything. When doing service or repair work on the machines be careful not to load the platforms more than permitted in the applicable standards. Before entering a tunnel or similar structure, make sure the ventilation is adequate.

 

CAUTION:  If you notice a loose grating, step or railing or any other danger spot on the walkways, inform the maintenance staff immediately.

 

NOTE:  Regularly check all service platform screw joints for tightness, for instance: fastening of gratings and steps, fastening of stairs and ladders & fastening of railings.

 

NOTE:  When carrying tools etc., note that the walkway widths may vary, especially the stairways which are usually narrower than the actual platforms.

 

Wood handling operational safety

It is obligatory to wear a safety helmet within the operating range of a log handling crane.

When unloading logs from wagons or lorries, use safe ladders or platforms to climb into or down from a wagon or vehicle.

It is forbidden to walk or work under a suspended load or on its travel path.

Beware of any working machines and vehicles in the log and chip storage yards.

Check that there is no debris, snow or other similar material accumulated in the structures because such material might prevent operation.

Be sure to continuously record the operation events and disturbances to be able to analyze them afterwards if necessary.

Debarking, chipping, flaking and screening

During operation, pay attention to the material flow and try to keep the capacity as even as possible.

If it is necessary to step on the log belt conveyor when clearing a jam in the chipper, make sure that unintentional start of the belt is prevented and use a safety harness.

Pay attention to potential risks when clearing a jam with a crane.

Be sure to wear a safety helmet and safety shoes and to use appropriate tools when clearing a jam.

It is forbidden to enter the barking drum without the supervisor's permission.

Pay attention to the danger of the pile collapsing when working on bark and chip piles.

The conveyor structures must be cleaned at least once a week. Special attention should be paid to the adjustment and cleaning of the cleaning scrapers.

Chipper

The master power switch must be tagged and locked out at all times when chipper is not in operation or whenever servicing chipper.

Do not remove or loosen chipper hood when chipper disc is rotating.

Do not operate unless all drive equipment is properly guarded.

All parts fastened to chipper disc must be installed using correct torque on all holding bolts and capscrews. See OEM instruction manual.

Knife Change: Containers should be used to transport disc knives. Safety gloves and safety glasses should be worn during knife change. Rawhide or lead head hammers and proper scraping tools should be provided.

Chipper disc to be rotated by manpower only following each knife change to check for proper running clearance of chipper disc assembly.

When checking spout and bedknife relationship or checking spout for wear, a safety belt is to be used by the man performing this function (only after turning off master power switch).

Ear protection must be worn by the chipper operator.

Fire retardant gloves, apron, and face shield must be used by personnel babbitting chipper disc knives.

Do not weld on chipper shaft.

Do not weld on chipper disc without formal instructions from the chipper manufacturer.

The chipper manufacturer cannot be held responsible for chipper operation unless new or repaired parts are furnished by the chipper manufacturer.

 

IMPORTANT:  A chipper warnings decal is affixed to all chippers at time of manufacture. This decal must remain on the chipper at all times and should not be painted over. In the event it is inadvertently removed or defaced, the chipper manufacturer will replace it free of charge.

 

Risks

Risks during repair work:

• the machine starts at the wrong time
• remote control
• safety devices are switched off
• risks due to mechanical parts such as conveyors, rollers, belts etc.

Risks due to material flow:

• material jammed in hoppers, chutes etc.
• stones, scrap metal and other foreign objects in material flow
• material spillage over conveyor edges
• careless removal of material from conveyors

Incorrect operation or action:

• All incorrect methods of operation present a potential accident risk.
• Conveyor belt misalignment, for instance, is caused by some factor which should be eliminated first to make the belt function correctly.
• Bear in mind that the reaction time of an individual working on conveyors is about 1 second, during which time a conveyor belt, for instance, runs 1 to 3 m forward. It is impossible to make the belt stop instantly but it will run another 5 to 15 m even when the conveyor has been switched off.
• For low-speed conveyors the stopping time is shorter but similar caution should be used.
• When loading logs onto a conveyor, grave danger is caused by logs rolling over conveyor edges; frozen logs are especially slippery.
• Strict attention should be paid to chipper infeed: it is strictly forbidden to clear any jams from the chipper spout unless the chipper has stopped completely.
• In the barking drum discharge point, dropping logs present a potential hazard if any efforts are made to raise the running capacity beyond the design values.
• If knives are not replaced in time, the result often is jamming or blockage and their removal presents a potential hazard.

Before equipment start-up

WARNING:  Check the equipment and make sure the safety guards are in place and there is nothing else to prevent the start-up. If the equipment to be started up is not within sight or has no camera monitoring system, make sure it can be safely started by spot-checking on site (or by walkie-talkie).

 

On equipment start-up, the start-up alarm system should provide a signal (sound/light) for 10 seconds, after which should be a 10 second pause before the first equipment starts.

During operation

DANGER:  The material (logs, chips, bark, fines etc.) infeed and discharge should be arranged in such a way that they do not jam the machine. If the machine does get jammed, however, extreme caution should be taken when clearing the jam. Lack of caution may be fatal.

 

WARNING:  Avoid standing near the machines. Careless movement near the machines or climbing onto any machine may be fatal. It is strictly forbidden to touch any moving or rotating parts. Do not remove any jamming material while the machine is running. A safety helmet and other personal protectors should be worn (for instance ear defenders when exposed to noise).

 

The drive unit safety guards and machine covers should be in place and the service and inspection doors closed to avoid any injury or damage caused by squeezing, jamming etc.

It is strictly forbidden to exceed the performance capacities specified for the machines.

Observe the machines daily, because malfunction or machine failures may result in dangerous situations.

For more information on safe woodyard operations, contact your Valmet representative.